Researchers Database

NAGAOKA, Shinichi

    Graduate School of Science and Engineering Engineering for Production and Environment Professor
    Graduate School of Science and Engineering (Science) Professor
Last Updated :2020/10/27

Researcher Information

Degree

  • D. Sc.(Kyoto University)

URL

J-Global ID

Research Interests

  • Core Excitation Dynamics   Photochemistry   Physical Chemistry   Chemical Education   

Research Areas

  • Nanotechnology/Materials / Basic physical chemistry

Academic & Professional Experience

  • 2006/04 - Today  Graduate University of Science and Engineering, Ehime UniversityProfessor
  • 2007/10 - 2008/03  Graduate School of Engineering, Mie UniveristyPart-Time Lecturer
  • 2005/08 - 2006/03  Faculty of Science, Ehime UniversityProfessor
  • 2001/04 - 2005/07  Faculty of Science, Ehime UniversityAssociate Professor
  • 2004/02 - 2004/03  The University of the AirPart-Time Lecturer
  • 1999/07 - 2002/06  Hiroshima Synchrotron Radiation Center, Hiroshima UniversityVisiting Researcher
  • 2001/04 - 2001/09  Institute for Solid State Physics, the University of TokyoVisiting Researcher
  • 1999/05 - 2001/03  Faculty of Science, Ehime UniversityPart-TIme Lecturer
  • 1999/04 - 2001/03  Institute for Molecular Science極端紫外光科学研究系Associate Professor
  • 1989/10 - 1999/03  Faculty of Science, Ehime UniversityAssociate Professor
  • 1994/07 - 1995/01  Department of Chemistry, University of Minnesota, USAVisiting Professor
  • 1989/04 - 1989/10  The Graduate University for Advanced StudiesResearch Associate
  • 1985/10 - 1989/10  Institute for Molecular Science分子集団研究系Research Associate
  • 1983/04 - 1985/09  Hokkaido University, Research Institute for Applied ElectricityDivision of ChemistryResearch Associate
  • 1982/04 - 1983/03  Japanese Society for Promotion of ScienceGraduate Fellowship

Education

  • 1980/04 - 1983/03  Kyoto University  Doctoral Program, Graduate School of Science  Division of Chemistry
  • 1978/04 - 1980/03  Kyoto University  Master Program, Graduate School of Science  Division of Chemistry
  • 1974/04 - 1978/03  Kyoto University  Faculty of Science  Department of Chemistry

Association Memberships

  • ビタミンE研究会   分子科学会   THE VACUUM SOCIETY OF JAPAN   日本ビタミン学会   分子科学研究会   日本化学会   Japan Society for Molecular Science (略称JSMS)   The Vitamin Society of Japan   The Chemical Society of Japan   

Published Papers

  • Y. Shinde, S. Yamamoto, K. Mukai, S. Nagaoka
    Chem. Lett. 日本化学会 in press 2020/11 [Peer-reviewed]
     Scientific journal
  • Shin ichi Nagaoka, Osamu Takahashi, Yasumasa Hikosaka
    Chemical Physics Elsevier 534 110756  0301-0104 2020/06 [Peer-reviewed]
     Scientific journal 
    © 2020 Elsevier B.V. L23VV Auger decays caused by Si:2p core-level photoionization in Cl3SiSi(CH3)3 vapor have been studied by means of photoelectron Auger-electron coincidence spectroscopy. Upon the Si:2p photoionization, Cl3Si(CH2)nSi(CH3)3 (n = 0–2) shows two core-photoelectron emissions that are distinguishable by the silicon site. Cl3SiCH2CH2Si(CH3)3 (n = 2) and so forth, which have a long inter-site bridge, remember the initially core-ionized silicon-site and show site-specific fragmentation. In contrast, Cl3SiSi(CH3)3, which has direct Si[sbnd]Si bonding (n = 0), forgets the initially core-ionized silicon-site and shows negligible site-specificity in the final fragmentation stage. A reduction of the site specificity in Cl3SiSi(CH3)3 starts during a Si:L23VV Auger decay and its reduction process can be explained in terms of an interatomic-Coulombic-decay-like mechanism. Another site-specificity reduction, caused by inter-site energy randomization, occurs after every Si:L23VV Auger decay.
  • Hisako Sato, Kazuyoshi Takimoto, Masaru Kato, Shin Ichi Nagaoka, Kenji Tamura, Akihiko Yamagishi
    Bulletin of the Chemical Society of Japan 93 (2) 194 - 199 0009-2673 2020/02 [Peer-reviewed]
     Scientific journal 
    © 2020 The Chemical Society of Japan. An ultrathin film was prepared by hybridizing a cationic Ir(III) complex with exfoliated nanosheets of clay minerals such as natural montmorillonite (denoted by MON) or synthetic saponite (denoted by SAP). The utilized Ir(III) complex with two long alkyl chains was [Ir(dfppy)2(dc9bpy)]+ (fppyH = 2-(2¤,4¤-difluorophenyl)pyridine; dc9bpy = 4,4¤-dinonyl-2,2¤-bi-pyridine) (denoted by DFPPY). Hybridization was performed at an air-water interface between a floating monolayer of the Ir(III) complex and the nanosheets exfoliated in an aqueous subphase. The hybrid floating film thus formed was transferred onto a hydrophilic quartz plate by a vertical dipping method. The emission from the deposited films exhibited rapid reversible change of intensity in response to the introduction or evacuation of oxygen gas in the pressure range of 0.1101.3 kPa and the temperature range from 253 K to 313 K. The lifetime of the emission decay was measured as a function of oxygen pressure, confirming the occurrence of dynamic quenching of excited Ir(III) complexes by oxygen molecules.
  • Kazuo Mukai, Masayuki Hirata, Junya Ito, Taiki Shiomi, Kiyotaka Nakagawa, Shin Ichi Nagaoka
    Journal of Oleo Science 日本油化学会 69 (1) 7 - 22 1345-8957 2020/01 [Peer-reviewed]
     Scientific journal 
    © 2020 by Japan Oil Chemists’ Society. Recently, singlet-oxygen (1O2) quenching and aroxyl-radical (ArO・) scavenging rates (kQ and kS, respectively) of eight vegetable oils were measured in the ethanol/chloroform/D2O solution. Furthermore, the kQ and kS values and concentrations of four tocopherols and four tocotrienols contained in the vegetable oils were measured. In this study, the concentrations of nine fatty acids (including stearic, oleic, linoleic, and linolenic acids) comprising the above-mentioned eight vegetable oils were determined by gas chromatography. The kQ and kS values for ethyl stearate, ethyl oleate, ethyl linoleate, methyl linolenate, and glyceryl trioleate in the ethanol/chloroform/D2O solution were measured by UV-vis spectrophotometry. Based on the results obtained for the above-mentioned fatty acid esters, the kQ and kS values were estimated for nine fatty acids. Furthermore, comparisons of kQ values observed for the vegetable oils with the sum of AO-i AO-i the product {∑kQ [AO-i]} of the kQ values obtained for each antioxidant-i (AO-i) and the concentrations ([AO-i]) of AO-i (i.e., four tocopherols (& four tocotrienols) and nine fatty acids) contained in vegetable oils were performed. Based on the results, a detailed comparison of the contributions of the tocopherols (and tocotrienols) and the fatty acids to the1O2-quenching rate constants (kQ) was performed. This indicated that both the tocopherols (and tocotrienols) and the fatty acids contribute to the1O2-quenching. A similar comparison was conducted for the ArO・-scavenging rate constants (kS). The results suggested that only the tocopherols (and tocotrienols) contained in the oils contributed to the ArO・-scavenging, with negligible contribution from the fatty acids.
  • K. Mukai, K. Nagai, A.Ouchi, T. Suzuki, K. Izumisawa, S. Nagaoka
    Int. J. Chem. Kinetics Wiley 51 (9) 643 - 656 0538-8066 2019/09 [Peer-reviewed]
     Scientific journal 
    © 2019 Wiley Periodicals, Inc. Measurements of aroxyl radical (ArO • )-scavenging rate constants ((Formula presented.)) of antioxidants (AOHs) (α-tocopherol (α-TocH) and three catechins (CatHs) (ie, epicatechin (EC), epigallocatechin (EGC), and epigallocatechin gallate (EGCG)) were performed in ethanol solution, using stopped-flow spectrophotometry. (Formula presented.) values were measured not only for each AOH, but also for the mixtures of two AOHs (α-TocH and CatH). A notable synergistic effect that the (Formula presented.) value of α-TocH increases 1.29, 1.84, and 1.65 times under the coexistence of constant concentrations of EC, EGC, and EGCG, respectively, was observed for the solutions including α-TocH and CatH. Similarly, (Formula presented.) values of CatHs (EC, EGC, and EGCG) increased 1.72, 2.25, and 2.34 times under the coexistence of constant concentrations of α-TocH, respectively. UV-Vis absorption of α-tocopheroxyl radical (α-Toc • ) (λ max  = 428 nm), which had been produced by reaction of α-TocH with ArO • , decreased remarkably under the coexistence of α-TocH and CatHs due to the fast α-TocH-regeneration reaction by CatHs. The result suggests that the prooxidant reaction due to α-Toc • is suppressed by the coexistence of CatHs. By analyzing the formation and decay curves of α-Toc • , it has been ascertained that one molecule of EGCG having three OH groups at B-ring may rapidly regenerate three molecules of α-Toc • to α-TocH.
  • Shin ichi Nagaoka, Naofumi Nakayama, Hiroyuki Teramae, Umpei Nagashima
    Chemical Physics 522 77 - 83 0301-0104 2019/06 [Peer-reviewed]
     Scientific journal 
    © 2019 Elsevier B.V. Ionization energies of catechins were calculated by using B3LYP density functional method with 6-31G** basis set. Then, conformations of catechins were extensively explored. Geometry optimizations starting from the explored conformers were made not only for the neutral species but also for the radical cation. The ionization energy of each catechin was estimated as the energy difference between the most stable geometries obtained for the neutral species and radical cation. Tendency of experimental oxidation potential in catechins is well reproduced by this calculation, and the ionization energy correlates well with the singlet-oxygen quenching efficiency in case that stereochemistry of attachment at the 3-position is common. Electron transfer from catechins plays an important role in the singlet-oxygen quenching, free-radical scavenging and recycling from vitamin E radical to vitamin E. The reason for discrepancy among antioxidant efficiencies with regard to the ionization energy dependence is explained.
  • T. Kakiuchi, K. Ikeda, K. Mase, S. Nagaoka
    Surf. Sci. 681 9 - 17 0039-6028 2019/03 [Peer-reviewed]
     Scientific journal 
    © 2018 The effect on the local valence electronic states of Sin+ suboxide components (n = 2, 3, and 4) of hafnium deposited on a low-index Si(110) substrate is investigated by Si-L23VV Auger electron Sin+-2p photoelectron coincidence spectroscopy (Si-L23VV-Sin+-2p APECS), and the chemical states and stabilities are discussed. Hafnium-covered Si(110) is immediately oxidized to HfO2 and SiO2 because hafnium serves as an effective catalyst for Si oxidation. Therefore, a HfO2/Sin+-(sub)oxide/Si(110) [HfO2/Sin+/Si(110)] structure is easily formed (n = 1, 2, 3, and 4). Oxygen diffusion from HfO2 layers toward the Si(110) substrate is promoted by annealing at 923 K. Oxygen atom desorption from the HfO2/Sin+/Si(110) surface occurs after annealing at 1073 K, and HfSi2 islands (i-HfSi2) are formed with a partly exposed Si(110)-16 × 2 double domain (DD) surface. i-HfSi2 shows low reactivity toward O2 molecules, whereas the exposed Si(110)-16 × 2 DD surface is immediately oxidized. Here, a i-HfSi2/Sin+-(sub)oxide/Si(110) (i-HfSi2/Sin+/Si(110)) structure is formed. Furthermore, we measure the Si-L23VV-Sin+-2p APECS spectra of Sin+ in the HfO2/Sin+/Si(110) and the i-HfSi2/Sin+/Si(110) structures (n = 2, 3, and 4) to evaluate the local valence electronic states of the Sin+ (sub)oxide components. The binding energy at the valence band maximum (BEVBM) of Sin+ in the i-HfSi2/Sin+/Si(110) structure is lower than 1.5 ± 0.7 eV as compared to that in the HfO2/Sin+/Si(110) structure (n = 2, 3, and 4). The local valence electric states of the nearest neighbors and the second neighbors through oxygen of Sin+ are determined to affect those of the Sin+ atom (n = 2, 3, and 4). The Sin+ atoms in the i-HfSi2/Sin+/Si(110) structure can directly bond to hafnium atoms as the nearest neighbors and most commonly have Sim+ atoms in lower ionic valence states as second neighbors (m < 4), whereas the Sin+ atoms in the HfO2/Sin+/Si(110) structure cannot form this bond. In addition, the existence of Hf silicide and Si in lower ionic valence states can reduce the band gap of the HfO2/Si(110) structure.
  • T. Kokubo, S. Nagaoka, H. Teramae, U.Nagashima:
    J. Comput. Chem. Jpn. 日本コンピュータ化学会 18 (4) 169 - 175 2019 [Peer-reviewed]
     Scientific journal
  • Kazuo Mukai, Ayaka Ohara, Junya Ito, Masayuki Hirata, Eri Kobayashi, Kiyotaka Nakagawa, Shin-Ichi Nagaoka
    Journal of oleo science 68 (1) 21 - 31 1345-8957 2019/01 [Peer-reviewed]
     Scientific journal 
    A kinetic study of the reaction of singlet oxygen (1O2) with eight vegetable oils 1-8 containing different concentrations of tocopherols (Tocs) and tocotrienols (Toc-3s) was performed. The second-order rate constants (kQ) for the reaction of 1O2 with vegetable oils 1-8 (rice bran, perilla, rape seed, safflower, grape seed, sesame, extra virgin olive, and olive oils) were measured in ethanol/chloroform/D2O (50:50:1, v/v/v) solution at 35°C using UV-vis spectrophotometry. Furthermore, comparisons of kQ values determined for the above oils 1-8 with the sum of the product {∑kQAO-i [AO-i]/105} of the kQAO-i values obtained for each antioxidant (AO-i) and concentration (in mg/100 g) ([AO-i]/105) of AO-i (Tocs and Toc-3s) contained in the oils 1-8 were performed. The observed kQ values were not reproduced by the kQ values calculated using only the concentrations of the four Tocs and Toc-3s. These results suggest that the contribution of fatty acids contained in the oils 1-8 is also necessary to fully explain the kQ values. Recently, the second-order rate constants (kS) for the reaction of aroxyl radical (ArO・) with the same vegetable oils 1-8 were measured in the same solvent at 25℃ using stopped-flow spectrophotometry (Ref. 23). The kS values obtained could be well explained as the sum of the product {Σ kSAO-i [AO-i]/105} of the kSAO-i and the [AO-i]/105 of AO-i (Tocs and Toc-3s) contained in the vegetable oils.
  • S. Nagaoka, T. Kokubo, H. Teramae, U. Nagashima
    J. Chem. Educ. 95 (9) 1579 - 1586 0021-9584 2018/09 [Peer-reviewed]
     Scientific journal 
    © 2018 American Chemical Society and Division of Chemical Education, Inc. At an advanced stage of learning quantum chemistry, undergraduate students usually encounter simple Hückel-molecular-orbital (HMO) theory, whose primitive approach gives very useful insight into the electronic structure of π-conjugated molecules. However, on one hand, computational HMO software, when programmed without using molecular symmetry, does not necessarily output chemically reasonable shapes of degenerate molecular-orbitals in benzene. On the other hand, separately inputting the molecular symmetry into the HMO calculation is mathematically redundant (i.e., duplicate information input). To solve this problem, in this study, a Microsoft Excel macro for obtaining reasonable HMOs of highly symmetric molecules such as benzene was developed. Furthermore, two other Excel macros for readily drawing quantitative contour plots of HMOs were created as student-friendly tools. The practical training in simple HMO theory proposed in the present report using these three macros will be very useful for undergraduate teaching of quantum chemistry in terms of clearly showing the theoretical concept.
  • K. Mukai, E. Ishikawa, A. Ouchi, S. Nagaoka, K. Abe, T. Suzuki, K. Izumisawa
    Lipids 53 (6) 601 - 613 0024-4201 2018/06 [Peer-reviewed]
     Scientific journal 
    © 2018 AOCS Recently, a new assay method that can quantify the singlet oxygen-absorption capacity (SOAC) of antioxidants (AO) and food extracts in homogeneous organic solvents has been proposed. In the present study, second-order rate constants (kQ) for the reaction of singlet oxygen (1O2) with vitamin E homologs (α-, β-, γ-, and δ-tocopherols [Toc] and α-, β-, γ-, and δ-tocotrienols [Toc-3]) were measured in an aqueous Triton X-100 (5.0 wt%) micellar solution (pH 7.4). Toc-3 showed kQvalues larger than those of Toc in a micellar solution, although Toc and Toc-3 showed the same kQvalues in a homogeneous solution. Similar measurements were performed for 5 palm oil extracts 1–5 and one soybean extract 6, which contained different concentrations of Toc, Toc-3, and carotenoids. It has been clarified that the1O2-quenching rates (kQ) (that is, the relative SOAC value) obtained for extracts 3–6 may be explained as the sum of the product (Formula presented.) of the rate constant ((Formula presented.)) and the concentration ([AO-i]/100) of AO-i contained. The UV–vis absorption spectra of Toc and Toc-3 were measured in a micellar solution and chloroform. The results obtained demonstrated that the kQvalues of AO in homogeneous and heterogeneous solutions vary notably depending on (1) polarity (dielectric constant [ε]) of the reaction field between1O2and AO, (2) the local concentration of AO, and (3) the mobility of AO in solution. The results suggest that the SOAC method is applicable to the measurement of1O2-quenching activity of general food extracts in a heterogeneous micellar solution.
  • Kazuo Mukai, Yuki Bandoh, Junya Ito, Eri Kobayashi, Kiyotaka Nakagawa, Shin ichi Nagaoka
    JAOCS, Journal of the American Oil Chemists' Society 95 (6) 731 - 742 0003-021X 2018/06 [Peer-reviewed]
     Scientific journal 
    © 2018 AOCS A detailed kinetic study was performed for the reaction of the aroxyl radical (ArO•) with eight vegetable oils 1–8, which contain different concentrations of α-, β-, γ-, and δ-tocopherols and -tocotrienols (-Tocs and -Toc-3s). The second-order rate constants (ks) and aroxyl radical absorption capacity (ARAC) values for the reaction of ArO• with vegetable oils 1–8 (rice bran 1, perilla 2, rapeseed 3, safflower 4, grape seed 5, sesame 6, extra virgin olive 7, and olive oils 8) were measured in ethanol/chloroform/D2O (50:50:1, v/v/v) solution at 25 °C using stopped-flow spectrophotometry. The ks value (16.1 × 10−3 L g−1 s−1) of rice bran oil 1 with the highest activity was 8.0 times larger than that (2.02 × 10−3) of olive oil 8 with the lowest activity. The concentrations (in mg 100 g−1) of α-, β-, γ-, and δ-Tocs and -Toc-3s contained in the vegetable oils 1–8 were determined using high performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS). From these results, it was clarified that the ArO•-scavenging rates (ks) (i.e., the relative ARAC value) obtained for the vegetable oils 1–8 may be well explained as the sum of the product (Formula presented.) of the rate constant ((Formula presented.)) and the concentration ([AOH-i]/105) of AOH-i (Tocs and Toc-3s) included in vegetable oils. The results suggest that the ARAC assay method might be used in the evaluation of antioxidant activity of general food extracts.
  • Shin-ichi Nagaoka, Yuki Bandoh, Umpei Nagashima, Keishi Ohara
    JOURNAL OF PHYSICAL CHEMISTRY A 121 (42) 8069 - 8079 1089-5639 2017/10 [Peer-reviewed]
     Scientific journal 
    Singlet-oxygen (O-1(2)) quenching, free-radical scavenging, and excited-state intramolecular proton-transfer (ESIPT) activities of hydroxyflavones, anthocyanidins, and 1-hydroxyanthraquinones were studied by means of laser, stopped-flow, and steady-state spectroscopies. In hydroxyflavones and anthocyanidins, the O-1(2) quenching activity positively correlates to the free radical scavenging activity. The reason for this correlation can be understood by considering that an early step of each reaction involves electron transfer from the unfused phenyl ring (B-ring), which is singly bonded to the bicyclic chromen or chromenylium moiety (A- and C-rings). Substitution of an electron-donating OH group at B-ring enhances the electron transfer leading to activation of the O-1(2) quenching and free-radical scavenging. In 3-hydroxyflavones, the OH substitution at B-ring reduces the activity of ESIPT within C-ring, which can be explained in terms of the nodal-plane model. As a result, the 102 quenching and free-radical scavenging activities negatively correlate to the ESIPT activity. A catechol structure at B-ring is another factor that enhances the free-radical scavenging in hydroxyflavones. In contrast to these hydroxyflavones, 1-hydroxyanthraquinones having an electron-donating OH substituent adjacent to the O-H-O = C moiety susceptible to ESIPT do not show a simple correlation between their O-1(2) quenching and ESIPT activities, because the OH substitution modulates these reactions.
  • Kazuo Mukai, Maya Yoshimoto, Masaharu Ishikura, Shin-ichi Nagaoka
    JOURNAL OF PHYSICAL CHEMISTRY B 121 (32) 7593 - 7601 1520-6106 2017/08 [Peer-reviewed]
     Scientific journal 
    A kinetic study of the reaction between an aroxyl radical (ArO center dot) and fatty acid esters (LHs 1-5, ethyl stearate 1, ethyl oleate 2, ethyl linoleate 3, ethyl linolenate 4, and ethyl arachidonate 5) has been undertaken. The second order rate constants (k(s)) for the reaction of ArO center dot with LHs 1-5 in toluene at 25.0 degrees C have been determined spectrophotometrically. The k(s) values obtained increased in the order of LH 1 < 2 < 3 < 4 < 5, that is, with increasing the number of double bonds included in LHs 1-5. The k(s) value for LH 5 was 2.93 X 10(-3) M-1 s(-1). From the result, it has been clarified that the reaction of ArO center dot with LHs 1-5 was explained by an allylic hydrogen abstraction reaction. A similar kinetic study was performed for the reaction of ArO center dot with six carotenoids (Car-Hs 1-6, astaxanthin 1, beta-carotene 2, lycopene 3, capsanthin 4, zeaxanthin 5, and lutein 6). The k(s) values obtained increased in the order of Car-H 1 < 2 < 3 < 4 < 5 < 6. The ks value for Car-H 6 was 8.4 x 10(-4) M-1 s(-1). The ks values obtained for Car-Hs 1-6 are in the same order as that of the values for LHs 1-5. The results of detailed analyses of the ks values for the above reaction indicated that the reaction was also explained by an allylic hydrogen abstraction reaction. Furthermore, the structure-activity relationship for the reaction was discussed by taking the result of density functional theory calculation reported by Martinez and Barbosa into account.<bold> </bold>
  • S. Nagaoka, H. Teramae, U. Nagashima
    J. Comput. Chem. Jpn Int. Ed. 3 2016-0068  2189-048X 2017/06 [Peer-reviewed]
     Scientific journal
  • Takuhiro Kakiuchi, Yuya Yoshizaki, Hiroyuki Kubota, Yuki Sato, Shin-ichi Nagaoka, Kazuhiko Mase
    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN PHYSICAL SOC JAPAN 86 (5) 054704  0031-9015 2017/05 [Peer-reviewed]
     Scientific journal 
    A Si(110)-16 x 2 single-domain (SD) surface is investigated in a site-selective way using Si L23VV Auger-electron Si-2p photoelectron coincidence spectroscopy (Si-L23VV-Si-2p APECS) and Si-2p photoelectron Si-L23VV Auger-electron coincidence spectroscopy (Si-2p-Si-L23VV PEACS). The Si(110)-16 x 2 SD consists of five Si-2p surface components (SC1-SC5) and has four semiconducting surface states (S-1-S-4). The Si-L2VV-Si-2p(1/2) APECS spectrum of the Si(110)-16 x 2 SD measured in coincidence with Si-2p(1/2) photoelectrons of SC3, SC4, and SC5 shows two small shoulders in the higher Auger electron kinetic energy (AeKE) region. These shoulders suggest Auger processes involving the surface states S-1 and S-3. The spectral weights of SC3, SC4, and SC5 Si-2p components are greatly enhanced in the Si-2p-Si-L23VV PEACS spectrum measured at Auger electrons with an AeKE of +5.0 eV relative to the Si L23VV peak. On the other hand, the spectral weights of SC1 and SC2 Si-2p components in the Si-2p-Si-L23VV PEACS spectrum show a maximum peak at a relative AeKE of +3 eV. These results directly support the correlations between the five surface components (SC1-SC5) and four surface states (S-1-S-4) in the adatom-buckling model for the Si(110)-16 x 2 SD proposed by Sakamoto et al.
  • Kazuo Mukai, Aya Ouchi, Nagao Azuma, Shingo Takahashi, Koichi Aizawa, Shin-ichi Nagaoka
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 65 (4) 784 - 792 0021-8561 2017/02 [Peer-reviewed]
     Scientific journal 
    Recently, a new assay method for the quantification of the singlet oxygen absorption capacity (SOAC) of antioxidants (AOs) and food extracts in homogeneous organic solvents was proposed. In this study, second-order rate constants (k(Q)) for the reaction of singlet oxygen (O-1(2)) with eight different carotenoids (Cars) and alpha-tocopherol (alpha-Toc) were measured in an aqueous Triton X-100 (5.0 wt %) micellar solution (pH 7.4, 35 degrees C), which was used as a simple model of biomembranes. The k(Q) and relative SOAC values were measured using ultraviolet visible (UV-vis) spectroscopy. The UV-vis absorption spectra of Cars and alpha-Toc were measured in both a micellar solution and chloroform, to investigate the effect of solvent on the k(Q) and SOAC values. Furthermore, decay rates (k(d)) of O-1(2) were measured in 0.0, 1.0, 3.0, and 5.0 wt % micellar solutions (pH 7.4), using time-resolved near-infrared fluorescence spectroscopy, to determine the absolute k(Q), values of the AOs. The results obtained demonstrate that the k(Q) values of AOs in homogeneous and heterogeneous solutions vary notably depending on (0 the polarity [dielectric constant (epsilon)] of the reaction field between AOs and O-1(2), (ii) the local concentration of AOs, and (iii) the mobility of AOs in solution. In addition, the k(Q) and relative SOAC values obtained for the Cars in a heterogeneous micellar solution differ remarkably from those in homogeneous organic solvents. Measurements of k(Q), and SOAC values in a micellar solution may be useful for evaluating the O-1(2) quenching activity of AOs in biological systems.
  • Shin-ichi Nagaoka, Takuhiro Kakiuchi, Joji Ohshita, Osamu Takahashi, Yasumasa Hikosaka
    JOURNAL OF PHYSICAL CHEMISTRY A 120 (50) 9907 - 9915 1089-5639 2016/12 [Peer-reviewed]
     Scientific journal 
    Site-specific electron relaxations caused by Si:2p core-level photoionizations in F3SiCH2CH2Si(CH3)(3) and Cl3SiCH2CH2Si(CH3)(3) vapors have been studied by means of the photoelectron Auger electron coincidence spectroscopy. F3SiCH2CH2Si(CH3)3 shows almost 100% site-specificity in fragmentation-caused by the Si:2p ionization. However, substitution of Cl for F of F3SiCH2CH2Si(CH3)(3) considerably reduces the site-specificity at the Si atom bonded to three halogen atoms, with the site-specificity at the Si site bonded to three methyl groups remaining largely unchanged. The site specificity reduction in Cl3SiCH2CH2Si(CH3)(3) is considered to take place during the transient period between Si:L23VV Auger electron emission and the subsequent fragmentation. The reason for the reduction can be explained in terms of some differences between these two molecules in the L23VV Auger decay at the Si site bonded to the three halogen atoms.
  • S. Nagaoka, H. Teramae, U. Nagashima
    Royal Australian Chemical Institute, Aust. J. Educ. Chem. 75 8 - 15 1445-9698 2016/09 [Peer-reviewed]
     Scientific journal 
    Adding a polarization function to a basis set for a molecular orbital calculation is frequently useful for producing accurate representations of chemical bonding. Adding a diffuse function is also important when considering anions. This article explains practical training that could greatly promote intuitive understanding of the general idea of adding these functions. In the training, students draw contour plots of molecular orbitals supplemented with and without each of the polarization and diffuse functions by using Microsoft Excel and visualize the effect of each addition
  • I. H. Suzuki, Y. Bandoh, T. Mochizuki, H. Fukuzawa, T. Tachibana, S. Yamada, T. Takanashi, K. Ueda, Y. Tamenori, S. Nagaoka
    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 49 (16) 165102  0953-4075 2016/08 [Peer-reviewed]
     Scientific journal 
    Cascade Si LVV Auger electron spectra at the photoexcitation of the Si 1s electron in a SiCl4 molecule have been measured using an electron spectrometer combined with monochromatized undulator radiation. In the instance of the resonant excitation of the Si 1s electron into the vacant molecular orbital a peak with high yield is observed at about 106 eV, an energy considerably higher than the energies of the normal LVV Auger electron. This peak is presumed to originate from the participator decay from the state with two 2p holes and one excited electron into the state with one 2p hole and one valence hole. Following the normal KL23L23 Auger transition, the cascade spectrum shows several peak structures, e.g. 63 eV, 76 eV and 91 eV. The peak at 91 eV is probably assigned to the second step Auger decay into states having a 2p hole together with two valence holes. These findings are similar to experimental results of SiF4. The former two peaks (63 eV and 76 eV) are ascribed to Auger transitions of Si atomic ions produced through molecular ion dissociation after the first step cascade decays, although the peak heights of atomic ions are lower than those of SiF4.
  • Kazuo Mukai, Kanae Nagai, Yoshifumi Egawa, Aya Ouchi, Shin-ichi Nagaoka
    JOURNAL OF PHYSICAL CHEMISTRY B 120 (29) 7088 - 7097 1520-6106 2016/07 [Peer-reviewed]
     Scientific journal 
    Detailed kinetic studies have been performed for reactions of aroxyl (ArO center dot) and alpha-tocopheroxyl (alpha-Toc(center dot)) radicals with five catecholamines (CAs) (dopamine (DA), norepinephrine (NE), epinephrine (EN), and 5- and 6-hydroxydopamine (5- and 6-OHDA)) and two catechins (epicatechin (EC) and epigallocatechin gallate (EGCG)) to clarify the free-radical-scavenging activity of CAs. Second order rate constants (k(s) and k(r)) for reactions of ArO center dot and alpha-Toc(center dot) radicals with the above antioxidants were measured in 2-propanol/water (5:1, v/v) solution at 25.0 degrees C, using single and double-mixing stopped-flow spectrophotometries, respectively. Both the rate constants (k(s) and k(r)) increased in the order NE < EN < DA < EC < 5-OHDA < EGCG < 6-OHDA. The k(s) and k(r) values of 6-OHDA are large and comparable to the corresponding values of ubiquinol-10 and sodium ascorbate, which show high free-radical-scavenging activity. The ultraviolet visible absorption of alpha-Toc(center dot) (lambda(max) = 428 nm), which was produced by the reaction of alpha-tocopherol (alpha-TocH) with ArO center dot, disappeared under the coexistence of CAs due to the alpha-TocH-regeneration reaction. The results suggest that the CAs may contribute to the protection from oxidative damage in nervous systems, by scavenging free radicals (such as lipid peroxyl radical) and regenerating alpha-TocH from the alpha-Toc(center dot) radical.
  • Shin-ichi Nagaoka, Akiko Nitta, Ai Suemitsu, Kazuo Mukai
    RSC ADVANCES ROYAL SOC CHEMISTRY 6 (53) 47325 - 47336 2046-2069 2016/05 [Peer-reviewed]
     Scientific journal 
    Recycling reactions of natural vitamin E (alpha-tocopherol) by catechins contained in green tea were studied with a double-mixing stopped-flow spectrophotometer. The second-order reaction rate constants of the catechins and deuterated analogues were determined by using a simulation, the activation energies were obtained from the temperature dependences, and the deuterium kinetic-isotope effects were examined. From these results, a tunneling effect was found to play an important role in the vitamin E recycling reactions by the catechins, and the structure-activity relationship was clarified. Furthermore, conditions under which the tunneling effect manifests itself in various vitamin E recycling reactions in biological systems and foods were suggested. A new alpha-tocopherol-recycling capacity assay-method was also proposed, and named an ATREC assay-method after the acronym.
  • Kazuo Mukai, Aya Ouchi, Shin-ichi Nagaoka, Masahiko Nakano, Kazuto Ikemoto
    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 80 (1) 178 - 187 0916-8451 2016/01 [Peer-reviewed]
     Scientific journal 
    Measurements of the reaction of sodium salt of pyrroloquinoline quinone (PQQNa(2)) with vitamin C (Vit C) were performed in phosphate-buffered solution (pH 7.4) at 25 degrees C under nitrogen atmosphere, using UV-vis spectrophotometry. The absorption spectrum of PQQNa(2) decreased in intensity due to the reaction with Vit C and was changed to that of pyrroloquinoline quinol (PQQH(2), a reduced form of PQQ). One molecule of PQQ was reduced by two molecules of Vit C producing a molecule of PQQH(2) in the buffer solution. PQQH(2), thus produced, was recycled to PQQ due to air oxidation. PQQ and Vit C coexist in many biological systems, such as vegetables, fruits, as well as in human tissues. The results obtained suggest that PQQ is reduced by Vit C and functions as an antioxidant in biological systems, because it has been reported that PQQH(2) shows very high free-radical scavenging and singlet-oxygen quenching activities in buffer solutions.
  • Kazuo Mukai, Eri Ishikawa, Takumi Abe, Aya Ouchi, Shin-ichi Nagaoka, Kazumasa Murata, Teruo Miyazawa, Kiyotaka Nakagawa
    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 日本農芸化学会 79 (12) 2063 - 2072 0916-8451 2015/12 [Peer-reviewed]
     Scientific journal 
    Measurements of singlet oxygen (O-1(2)) quenching rates (k(Q) (S)) and the relative singlet oxygen absorption capacity (SOAC) values were performed for seven rice bran extracts 1-7, which contained different concentrations of antioxidants (AOs) (such as alpha-, beta-, gamma-, and delta-tocopherols and -tocotrienols, three carotenoids (lutein, beta-carotene, and zeaxanthin), and gamma-oryzanol), in ethanol at 35 degrees C using UV-vis spectrophotometry. The concentrations of four tocopherols and four tocotrienols, three carotenoids, and gamma-oryzanol contained in the extracts were determined using HPLC-MS/MS, UV-HPLC, and UV-vis absorption spectroscopy, respectively. Furthermore, comparisons of k(Q) (S) (Obsd.) values observed for the above extracts 1-7 with the sum of the product {Sigma k(Q)(AO-i) (S) [AO-i]} of the k(Q)(AO-i) (S) values obtained for each AO-i and the concentration ([AO-i]) of AO-i contained in extracts 1-7 were performed. From the results, it has been ascertained that the SOAC method is applicable to general food extracts to evaluate their O-1(2)-quenching activity.
  • Kazuo Mukai, Asuka Nakamura, Shin-ichi Nagaoka, Aya Ouchi, Nagao Azuma
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 88 (10) 1503 - 1510 0009-2673 2015/10 [Peer-reviewed]
     Scientific journal 
    Measurement of the quenching rate constant (k(Q)) of singlet oxygen (O-1(2)) by a-tocopherol was performed in ethanol solution including four kinds of alkali and alkaline earth metal salts (NaClO4, Mg(ClO4)(2), MgCl2, and CaCl2) by varying concentrations of metal salts. A remarkable effect of metal salts on the k(Q) value of alpha-tocopherol was observed. The O-1(2)- quenching rate constant (k(Q)) decreased notably with increasing concentrations of metal salts, and reached a constant value for each salt at high concentration of the salt. For example, the k(Q) value (9.48 x 10(7) M(-1)s(-1)) obtained in the presence of 20 mM of Mg(ClO4)(2) was 46% of that (2.06 x 10(8) M-1 s(-1)) in the absence of metal salt. The k(Q) value decreased in the order of no metal salt > NaClO4 > CaCl2 > MgCl2 approximate to Mg(ClO4)(2) at the same concentration of the metal salts. The metal salts having a smaller ionic radius and a larger charge of the cation gave a smaller k(Q) value. Effects of anions were negligible. These metal cations coexist with alpha-tocopherol in foods and biological systems, suggesting that the metal cations may give a notable effect to the O-1(2)-quenching rate constant (k(Q)).
  • Takuhiro Kakiuchi, Masashi Tahara, Kazuhiko Mase, Shin-ichi Nagaoka
    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 84 (4) 044711  0031-9015 2015/04 [Peer-reviewed]
     Scientific journal 
    The local valence electronic states of Si3N4 films grown on Si(111)-7 x 7 [Si3N4/Si(111)] have been investigated by coincidence spectroscopy. The Si L23VV Auger electron spectra (AES) measured in coincidence with the Sin+ 2p photoelectrons of beta-Si3N4(0001)/Si(111)-8 x 8 indicate that the binding energy of the local valence electronic state at Sin+ increases as n increases. Si4+ L23VV AES measured as a function of the beta-Si3N4(0001) thickness show that the binding energy at the valence-band maximum (BEVBM) of beta-Si3N4(0001) decreases by 1.6 +/- 0.5 eV as the Si3N4 thickness decreases from 3.6 to 0.7 angstrom. The large decrease is attributed to the hybridization of the valence electronic state of Si3N4 with those of neighboring subnitrides and to the formation of beta-Si3N4(0001) islands. The BEVBM value of the 3.6-angstrom-Si3N4/Si(111)-quadruplet decreases by 0.7 +/- 0.6 eV from that of 3.6-angstrom-beta-Si3N4(0001)/Si(111)-8 x 8. The decrease in BEVBM is attributed to the different interface structures.
  • Shin-ichi Nagaoka, Hikaru Endo, Keishi Ohara, Umpei Nagashima
    JOURNAL OF PHYSICAL CHEMISTRY B 119 (6) 2525 - 2532 1520-6106 2015/02 [Peer-reviewed]
     Scientific journal 
    Excited-state intramolecular proton-transfer (ESIPT) and singlet-oxygen (O-1(2)) quenching activities of intramolecularly hydrogen-bonded 1-(acylamino)anthraquinones have been studied by means of static and laser spectroscopies. The ESIPT shows a substituent effect, which can be explained in terms of the nodal-plane model. The ESIPT activity positively and linearly correlates with their O-1(2) quenching activity. The reason for this correlation can be understood by considering ESIPT-induced distortion of their ground-state potential surface and their encounter complex formation with O-1(2). Intramolecularly hydrogen-bonded hydroxyanthraquinones found in aloe also show a similar positive and linear correlation, which can be understood in the same way.
  • T. Arai, S. Nagaoka, U. Nagashima, H. Teramae
    Society of Computer Chemistry, Japan, J. Comput. Chem. Jpn. 日本コンピュータ化学会 14 (6) 209 - 210 1347-1767 2015 [Peer-reviewed]
     Scientific journal
  • Kenji Fukuzawa, Aya Ouchi, Shin-Ichi Nagaoka, Akira Shibata, Kazuo Mukai
    Journal of Nutritional Science and Vitaminology 日本ビタミン学会、日本栄養・食糧学会 60 (6) 443 - 446 1881-7742 2014/12 [Peer-reviewed]
     Scientific journal 
    Vitamin E is localized in membranes and functions as an efficient inhibitor of lipid peroxidation in biological systems. In this study, we measured the second-order rate constants (ks) for the reaction of tocotrienol homologues (α-, β-, γ-, and δ-Toc-3Hs) with the aroxyl radical (ArO•) used as a model for lipid peroxyl radicals (LOO•) in the membranes of egg yolk phosphatidylcholine (EYPC) vesicles by stopped-flow spectrophotometry, and compared them to those of tocopherol homologues (α-, β-, γ-, and δ-TocHs). The relative rate constants of Toc-3H homologues to α-Toc-3H in membranes (α/β/γ/δ=100/83.7/63.2/20.2) were not much different to those of TocH homologues to α-TocH (α/β/γ/δ=100/88.4/83.8/17.3). Each ks value of Toc-3H homologues in membranes was 60-80% of that of the corresponding TocH homologues except for the almost identical ks values of δ-homologues, but there was no difference in EtOH solution between each ks value of the corresponding homologues of Toc-3H and TocH. These results indicate that the difference of the alkyl-side chain structure of vitamin E causes a change in the mobility of vitamin E molecules and/or the location of their antioxidant OH-groups in membranes, resulting in lowered radical-trapping rates of Toc-3Hs. By use of the ratio of the kinh value of α-TocH with LOO• (3.20×106 M−1s−1) to the ks value of α-TocH with ArO• (8.05×104 M−1s−1) in chlorobenzene (that is, 39.8), the kinh value for the reaction of α-TocH with LOO• in membrane was estimated to be 1.03×105 M−1s−1.
  • Kazuo Mukai, Eri Ishikawa, Aya Ouchi, Shin-ichi Nagaoka, Tomomi Suzuki, Katsuhiro Izumisawa, Taisuke Koike
    BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY 日本農芸化学会 78 (12) 2089 - 2101 0916-8451 2014/12 [Peer-reviewed]
     Scientific journal 
    Measurements of the singlet oxygen (O-1(2)) quenching rates (k(Q) (S)) and the relative singlet oxygen absorption capacity (SOAC) values were performed for 11 antioxidants (AOs) (eight vitamin E homologues (alpha-, beta-, gamma-, and delta-tocopherols and -tocotrienols (-Tocs and -Toc-3s)), two vitamin E metabolites (alpha- and gamma-carboxyethyl-6-hydroxychroman), and trolox) in ethanol/chloroform/D2O (50:50:1, v/v/v) and ethanol solutions at 35 degrees C. Similar measurements were performed for five palm oil extracts 1-5 and one soybean extract 6, which included different concentrations of Tocs, Toc-3s, and carotenoids. Furthermore, the concentrations (wt%) of Tocs, Toc-3s, and carotenoids included in extracts 1-6 were determined. From the results, it has been clarified that the O-1(2)-quenching rates (k(Q) (S)) (that is, the relative SOAC value) obtained for extracts 1-6 may be explained as the sum of the product {sigma k(Q)(AO-i) (S) [AO-i]/100} of the rate constant (k(Q)(AO-i) (S)) and the concentration ([AO-i]/100) of AO-i (Tocs, Toc-3s, and carotenoid) included.
  • A. Sagan, S. Tajima, N. Nakayama, U. Nagashima, H. Teramae, S. Nagaoka
    Society of Computer Chemistry, Japan, J. Comput. Chem. Jpn. 13 (4) 250 - 256 1347-3824 2014/10 [Peer-reviewed]
     Scientific journal
  • Aya Ouchi, Shin-ichi Nagaoka, Tomomi Suzuki, Katsuhiro Izumisawa, Taisuke Koike, Kazuo Mukai
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 62 (32) 8101 - 8113 0021-8561 2014/08 [Peer-reviewed]
     Scientific journal 
    Measurements of aroxyl radical (ArO center dot)-scavenging rate constants (k(s)(AOH)) of antioxidants (AOHs) [alpha-, beta-, gamma-, and delta-tocopherols (TocHs) and -tocotrienols (Toc-3Hs)] were performed in ethanol solution via stopped-flow spectrophotometry. k(s)(AOH) values of alpha-, beta-, gamma-, and delta-Toc-3Hs showed good agreement with those of the corresponding alpha-, beta-, gamma-, and delta- TocHs. k(s)(AOH) values were measured not only for each antioxidant but also for mixtures of two antioxidants: (i) alpha-TocH with beta-, gamma-, or delta-TocH and (ii) alpha-TocH with alpha-, beta-, gamma-, or delta-Toc-3H. A synergistic effect in which the k(s)(AOH) value increases by 12% for gamma-TocH (or by 12% for gamma-Toc-3H) was observed for solutions including alpha-TocH and gamma-TocH (or gamma-Toc-3H). On the other hand, a cancel effect in which the k(s)(AOH) value decreases (a) by 7% for beta-TocH (or 11% for beta-Toc-3H) and (b) by 24% for delta-TocH (or 25% for delta-Toc-3H) was observed for solutions including two kinds of antioxidants. However, only a synergistic effect may function in edible oils, because contents of beta- and delta-TocHs (and beta- and delta-Toc-3Hs) are much less than those of alpha- and gamma-TocHs (and alpha- and gamma-Toc-3Hs) in many edible oils. UV-vis absorption of alpha-Toc(center dot), which was produced by reaction of alpha-TocH with ArO center dot, decreased remarkably for coexistence of alpha-TocH with beta-, gamma-, or delta-TocH (or beta-, gamma-, or delta-Toc-3H), indicating that the prooxidant effect of alpha-Toc(center dot) is suppressed by the coexistence of other TocHs and Toc-3Hs.
  • Shin-ichi Nagaoka, Hikaru Endo, Kanae Nagai, Osamu Takahashi, Yusuke Tamenori, Isao H. Suzuki
    JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA 195 18 - 25 0368-2048 2014/08 [Peer-reviewed]
     Scientific journal 
    A variety of photoelectron and Auger-electron spectra of 1,1,1-trimethyltrichlorodisilane vapor (Cl3SiSi(CH3)(3)) were measured by using monochromatized synchrotron radiation and a hemispherical electron energy analyzer. The measured spectra were interpreted with the aid of some calculations by means of the outer valence Green's function (OVGF) method or the density-functional-theory (DFT) method. Since Cl3SiSi(CH3)(3) consists of -SiCl3 and -Si(CH3)(3) moieties, the experimental core-electron binding-energies were compared with those of tetrachlorosilane and tetramethylsilane (SiCl4 and Si(CH3)(4), respectively). This comparison showed that electronic properties of Cl3SiSi(CH3)(3) hold a close correlation with those of SiCl4 and Si(CH3)(4). Si:L23VV, CI:L23VV and C:KVV Auger-electron spectra of Cl3SiSi(CH3)(3) also showed profiles close to those expected from the spectra of SiCl4 and Si(CH3)(4). The results obtained here were discussed in conjunction with electronic relaxation leading to site-specific fragmentation. (C) 2014 Elsevier B.V. All rights reserved.
  • Hisako Sato, Kenji Tamura, Keishi Ohara, Shin-ichi Nagaoka
    NEW JOURNAL OF CHEMISTRY 38 (1) 132 - 139 1144-0546 2014/01 [Peer-reviewed]
     Scientific journal 
    Mono- and multi-layered films comprised of amphiphilic cationic iridium(III) complexes hybridized with the exfoliated nanosheets of synthetic saponite were prepared by the modified Langmuir-Blodgett method. Three iridium(III) complexes with different emission maxima (lambda(max)) were used as incorporated complexes: [Ir(dfppy)(2)(dc9bpy)](+) (lambda(max) = 500 nm) (dfppyH = 2-(4',6'-difluorophenyOpyridine; dc9bpy = 4,4'-dinonY1-2,2'-bipyridine) [Ir(ppy)(2)(dc9bpy)](+) (lambda(max) = 550 nm) (ppyH = 2-phenylpyridine) and [Ir(piq)(2)(dc9bpy)](+) (lambda(max) = 590 nm) (piqH = 1-phenylisoquinoline) for blue, yellow and red emissions, respectively. Six triple-layered films with different layer sequences were fabricated by layer-by-layer deposition onto quartz substrates. Stationary emission spectra were recorded on the prepared films under vacuum and at various oxygen pressures Notably the change in the spectral shape at surrounding oxygen pressure depended remarkably on the layer sequence. Quenching by oxygen molecules was analyzed by applying a two-site model to the Stern-Volmer plots. The present nanometer-thick films were regarded as a benchmark for an optical device emitting different visible lights in response to oxygen pressure.
  • A. Sagan, S. Tajima, N. Nakayama, U. Nagashima, H. Teramae, S. Nagaoka
    Society of Computer Chemistry, Japan, J. Comput. Chem. Jpn. 12 (4) 230 - 234 1347-3824 2013/12 [Peer-reviewed]
     Scientific journal
  • A. Ouchi, K. Ikemoto, M. Nakano, S. Nagaoka, K. Mukai
    American Chemical Society, J. Agric. Food Chem. AMER CHEMICAL SOC 61 (46) 11048 - 11060 0021-8561 2013/11 [Peer-reviewed]
     Scientific journal 
    Measurements of aroxyl radical (ArO•)-scavenging rate constants (ksAOH) of antioxidants (AOHs: pyrroloquinolinequinol (PQQH 2), α-tocopherol (α-TocH), ubiquinol-10 (UQ 10H2), epicatechin, epigallocatechin, epigallocatechin gallate, and caffeic acid) were performed in dimethyl sulfoxide (DMSO) solution, using stopped-flow spectrophotometry. The ksAOH values were measured not only for each AOH but also for the mixtures of two AOHs ((i) α-TocH and PQQH2 and (ii) α-TocH and UQ10H2). A notable synergistic effect that the ksAOH values increase 1.72, 2.42, and 2.50 times for α-TocH, PQQH2, and UQ10H2, respectively, was observed for the solutions including two kinds of AOHs. Measurements of the regeneration rates of α-tocopheroxyl radical (α-Toc•) to α-TocH by PQQH2 and UQ 10H2 were performed in DMSO, using double-mixing stopped-flow spectrophotometry. Second-order rate constants (kr) obtained for PQQH2 and UQ10H2 were 1.08 × 105 and 3.57 × 104 M-1 s-1, respectively, indicating that the kr value of PQQH2 is 3.0 times larger than that of UQ10H2. It has been clarified that PQQH2 and UQ10H2 having two HO groups within a molecule may rapidly regenerate two molecules of α-Toc • to α-TocH. The result indicates that the prooxidant effect of α-Toc• is suppressed by the coexistence of PQQH2 or UQ10H2. © 2013 American Chemical Society.
  • Isao H. Suzuki, Hikari Endo, Kanae Nagai, Osamu Takahashi, Yusuke Tamenori, Shin-ichi Nagaoka
    JOURNAL OF CHEMICAL PHYSICS 139 (17) 174314  0021-9606 2013/11 [Peer-reviewed]
     Scientific journal 
    Spectator resonant Auger electron spectra with the Si 1s photoexcitation of Cl3SiSi(CH3)(3) have been measured using an electron spectroscopic technique combined with undulator radiation. The transition with the highest intensity in the total ion yield (TIY) spectrum, coming from excitation of a Si 1s electron on the Cl-side into a vacant valence orbital, generates the resonant Auger decay in which the excited electron remains in this valence orbital. Photoexcitation of 1s electrons into some Rydberg orbitals induces Auger shake-down transitions, because higher-lying Rydberg orbitals in the two Si atoms closely positioned hold spatially overlapping considerably. A broad TIY peak slightly above the 1s ionization thresholds appreciably yields resonant Auger decays in which a slow photoelectron is re-captured into a higher-lying Rydberg orbital. The normal Auger peak shape at this photon energy is distorted due to a post-collision interaction effect. These findings provide a clear understanding on properties of the excited orbitals which are ambiguous in the measurement of the TIY only. (C) 2013 AIP Publishing LLC.
  • Shin-ichi Nagaoka, Kanae Nagai, Yuko Fujii, Aya Ouchi, Kazuo Mukai
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 61 (42) 10054 - 10062 0021-8561 2013/10 [Peer-reviewed]
     Scientific journal 
    A new free radical absorption capacity assay method is proposed with use of an aroxyl radical (2,6-di-tert-butyl-4-(4'-methoxyphenyl)phenoxyl radical) and stopped-flow spectroscopy and is named the aroxyl radical absorption capacity (ARAC) assay method. The free radical absorption capacity (ARAC value) of each tocopherol was determined through measurement of the radical-scavenging rate constant in ethanol. The ARAC value could also be evaluated through measurement of the half-life of the aroxyl radical during the scavenging reaction. For the estimation of the free radical absorption capacity, the aroxyl radical was more suitable than the DPPH radical, galvinoxyl, and p-nitrophenyl nitronyl nitroxide. The ARAC value in tocopherols showed the same tendency as the free radical absorption capacities reported previously, and the tendency was independent of an oxygen radical participating in the scavenging reaction and of a medium surrounding the tocopherol and oxygen radical. The ARAC value can be directly connected to the free radical-scavenging rate constant, and the ARAC method has the advantage of treating a stable and isolable radical (aroxyl radical) in a user-friendly organic solvent (ethanol). The ARAC method was also successfully applied to a palm oil extract. Accordingly, the ARAC method would be useful in free radical absorption capacity assay of antioxidative reagents and foods.
  • A. Sagan, M. Nakayama, U. Nagashima, H. Teramae, S. Nagaoka
    Society of Computer Chemistry, Japan, J. Comput. Chem. Jpn. 12 (3) 190 - 195 1347-3824 2013/09 [Peer-reviewed]
     Scientific journal
  • Kazuo Mukai, Aya Ouchi, Saori Nakaya, Shin-ichi Nagaoka
    JOURNAL OF PHYSICAL CHEMISTRY B 117 (28) 8378 - 8391 1520-6106 2013/07 [Peer-reviewed]
     Scientific journal 
    Measurements of aroxyl radical (ArO center dot)-scavenging rate constants (k(s)(AOH)) of antioxidants (AOHs) (alpha-tocopherol (alpha-TocH), ubiquinol-10 (UQ(10)H(2)), and sodium ascorbate (Na+AsH-)) were performed in 2-propanol/water (2-PrOH/H2O, 5/1, v/v) solution using stopped-flow spectrophotometry. k(s)(AOH) values were measured not only for each AOH but also for the mixtures of two AOHs ((i) alpha-TocH and UQ(10)H(2) and (ii) alpha-TocH and Na+AsH-). A notable synergistic effect that the k(s)(AOH) values increase 1.6, 2.5, and 6.8 times for alpha-TocH, UQ(10)H(2), and Na+AsH-, respectively, was observed for the solutions including two kinds of AOHs. Furthermore, measurements of the regeneration rates of alpha-tocopheroxyl radical (alpha-Toc(center dot)) to alpha-TocH by UQ(10)H(2) and Na+AsH- were performed in 2-PrOH/H2O using double-mixing stopped-flow spectrophotometry. Second-order rate constants (k(r)) obtained for UQ(10)H(2) and Na+AsH- were 2.01 x 10(5) and 1.19 x 10(6) M-1 s(-1), respectively. In fact, UV-vis absorption of alpha-Toc(center dot) (lambda(max) = 428 nm), which had been produced by reaction of alpha-TocH with ArO center dot, disappeared under the existence of UQ(10)H(2) or Na+AsH- due to the above fast regeneration reaction. The result indicates that the prooxidant effect of alpha-Toc(center dot) is suppressed by the coexistence of UQ(10)H(2) or Na+AsH-. As alpha-TocH, UQ(10)H(2), and ascorbate monoanion (AsH-) coexist in relatively high concentrations in plasma, blood, and various tissues, the above synergistic effect, that is, the increase of the free-radical-scavenging rate and suppression of the prooxidant reaction, may function in biological systems.
  • M. Kimura, H. Fukuzawa, K. Sakai, S. Mondal, E. Kukk, Y. Kono, S. Nagaoka, Y. Tamenori, N. Saito, K. Ueda
    Physical Review A - Atomic, Molecular, and Optical Physics 87 (4) 043414  1050-2947 2013/04 [Peer-reviewed]
     Scientific journal 
    We identified interatomic Coulombic decay (ICD) channels in argon dimers after spectator-type resonant Auger decay 2p-13d→3p -23d,4d in one of the atoms, using momentum-resolved electron-ion-ion coincidence. The results illustrate that the resonant core excitation is a very efficient way of producing slow electrons at a specific site, which may cause localized radiation damage. We find also that ICD rate for 3p-24d is significantly lower than that for 3p-23d. © 2013 American Physical Society.
  • I. H. Suzuki, Y. Kono, K. Sakai, M. Kimura, K. Ueda, Y. Tamenori, O. Takahashi, S. Nagaoka
    Journal of Physics B: Atomic, Molecular and Optical Physics 46 (7) 075101  0953-4075 2013/04 [Peer-reviewed]
     Scientific journal 
    Spectator resonant Auger electron spectra with the Si 1s photoexcitation of SiCl4 have been measured using an electron spectroscopic technique combined with undulator radiation. The transition with the highest intensity in the total ion yield (TIY) spectrum, coming from excitation of a 1s electron into the 9t2 valence orbital, generates the resonant Auger decay in which the excited electron remains in the 9t2 orbital. A TIY peak positioned slightly above the 1s ionization threshold induces Auger decay in which the slow photoelectron is re-captured into a higher lying Rydberg orbital or the normal Auger peak shape is distorted due to a post-collision interaction effect. Another structure above the threshold, originating from a doubly excited state, yields the normal Auger peak with the distortion of peak shape and a resonant Auger peak with a higher kinetic energy. These findings provide a clear understanding of the properties of the excited orbitals which were ambiguous previously. © 2013 IOP Publishing Ltd.
  • Shin-ichi Nagaoka, Hidemitsu Uno, Dan Huppert
    JOURNAL OF PHYSICAL CHEMISTRY B 117 (16) 4347 - 4353 1520-6106 2013/04 [Peer-reviewed]
     Scientific journal 
    Time-resolved emission of aloesaponarin I was studied with the fluorescence up-conversion and time-correlated single-photon-counting techniques. The rates of the excited-state intramolecular proton transfer, of the solvent and molecular rearrangements, and of the decay from the excited proton-transferred species were determined and interpreted in the light of time-dependent density functional calculations. These results were discussed in conjunction with UV protection and singlet-oxygen quenching activity of aloe.
  • Aya Seike, Kaoru Yamagami, Yoshimasa Kakitani, Miki Kuwajima, Hiroki Uoyama, Shin-ichi Nagaoka, Takahiro Nakae, Shigeki Mori, Tetsuo Okujima, Hidemitsu Uno
    RSC ADVANCES ROYAL SOC CHEMISTRY 3 (9) 3006 - 3016 2046-2069 2013/03 [Peer-reviewed]
     Scientific journal 
    Ethyl 12-oxo-4,11-dihydro-4,11-ethanonaphth[2,3-f]isoindole-1-carboxylate (2) was prepared from 7-tert-butoxynorbornadiene and quantitatively converted to ethyl naphth[2,3-f]isoindole-1-carboxylate (3) by the thermal or photochemical cheletropic reaction. Ethyl naphth[2,3-f] isoindole-1-carboxylate (3) existed in a 2H-form both in solution and as a solid, and gradually dimerized to give a dianthradiazafulvalene derivative under aerobic conditions.
  • I. H. Suzuki, Y. Kono, A. Ikeda, M. Oi, T. Ouchi, K. Ueda, Y. Tamenori, O. Takahashi, S. Nagaoka
    Journal of Chemical Physics 138 (2) 024302  0021-9606 2013/01 [Peer-reviewed]
     Scientific journal 
    Cascade Si LVV Auger decays following KL23L23 Auger transitions have been measured in SiF4 molecule using an electron spectrometer combined with monochromatized undulator radiation. Molecular cascade processes from the two 2p holes states largely generate wide band structures in the spectra due to sequential electron emission leading to multiple valence holes. However, a peak with high yield is observed for the first time at about 103 eV, an energy being considerably higher than the energies of the normal LVV Auger electron, in the instance of the resonant excitation of Si 1s electron into the vacant molecular orbital. This peak is presumed to originate from the participator decay from the state with two 2p holes and one excited electron into the state with one 2p hole and one valence hole. A similar peak with less intensity is detected in the photoexcitation of the 1s electron into a Rydberg orbital. After the normal KL23L 23 Auger transition, the resultant cascade spectrum shows several peaks, e.g., 61 eV, 76 eV, and 82 eV. The former two peaks are assigned to the Auger transitions of Si atoms produced through molecular ion dissociation after cascade decays, and the latter is probably ascribed to the second step Auger decay into states having a 2p hole together with two valence holes. © 2013 American Institute of Physics.
  • Kazuhiko Mase, Eiichi Kobayashi, Akira Nambu, Takuhiro Kakiuchi, Osamu Takahashi, Kiyohiko Tabayashi, Joji Ohshita, Shogo Hashimoto, Masatoshi Tanaka, Shin-ichi Nagaoka
    SURFACE SCIENCE 607 174 - 180 0039-6028 2013/01 [Peer-reviewed]
     Scientific journal 
    Ion desorption from condensed F3SiCD2CH2Si(CH3)(3) induced by Si-2p core-level ionizations of the F3Si- and the -Si(CH3)(3) sites (Si[F] and Si[Me]) was investigated using photoelectron photoion coincidence (PEPICO) spectroscopy, Auger photoelectron coincidence spectroscopy (APECS) and Auger electron photoion coincidence (AEPICO) spectroscopy. A Si-2p-F+ PEPICO peak appeared selectively in the Si[F]-2p region. Si-2p-H+ PEPICO peaks were, on the other hand, observed in both the Si[Me]- and Si[F]-2p regions. The structure of the Si-L23VV-Si[F]-2p Auger photoelectron coincidence spectrum (APECS) was quite different from that of the Si-L23VV-Si[Me]-2p APECS. Ab initio molecular orbital calculations qualitatively reproduced the measured APECSs. The peak positions in the Si-L23VV-F+ AEPICO spectrum were in good agreement with those in the Si-L23VV-Si[F]-2p APECS. The Si-L23VV-H+ AEPICO spectrum, on the other hand, showed no characteristic peaks. Based on these results we have concluded that the site-specific F+ desorption is stimulated by Si [F]-L23VV Auger processes, and that both the Si[Me]- and Si[F]-L23VV Auger decays are responsible for the non-site-specific H+ desorption. (c) 2012 Elsevier B.V. All rights reserved.
  • Hiroyuki Teramae, Shin-ichi Nagaoka, Umpei Nagashima
    CHEMISTRY LETTERS 41 (12) 1642 - 1643 0366-7022 2012/12 [Peer-reviewed]
     Scientific journal 
    The threshold bond distances of electron transfer in the typical heteronuclear diatomic molecules, HF, LiH, and HeH+ have been studied in conjunction with the dipole moments by using ab initio molecular orbital method. The electron transfer begins at 3 angstrom for HF, 6 angstrom for LiH, and 4 angstrom for HeH+, and the dipole moments have their maxima at 1.2 angstrom for HF, 2.4 angstrom for LiH, and 0.8 angstrom after the electrostatic correction for HeH+.
  • Kazuya Morimoto, Takahiro Nakae, Keishi Ohara, Kenji Tamura, Shin-ichi Nagaoka, Hisako Sato
    NEW JOURNAL OF CHEMISTRY 36 (12) 2467 - 2471 1144-0546 2012/12 [Peer-reviewed]
     Scientific journal 
    Langmuir-Blodgett (LB) films were prepared by hybridizing a floating monolayer of an amphiphilic cationic iridium(m) complex with clay particles in a subphase. Two kinds of iridium(III) complexes were used: [Ir(dfppy)(2)(dc9bpy)](+) (denoted by DFPPY: dfppyH = 2-(4',6'-difluoro-phenyl)pyridine; dc9bpy = 4,4'-dinonyl-2,2'-bipyridine) with the maximum emission wavelength (lambda(max)) at 500 nm and [Ir(ppy)(2)(dc9bpy)](+) (denoted by PPY: ppyH = 2-phenylpyridine) with lambda(max) at 550 nm. Stationary emission spectra were recorded on the following films under vacuum: {DFPPY or PPY/clay}(n) (n = 1-3), {DFPPY/clay/PPY/clay} and {PPY/clay/DFPPY/clay}. The intensity of emission from {PPY/clay}(n) or {DFPPY/clay}(n) increased nearly in proportion to the layer number (n). Both DFPPY and PPY emitted simultaneously from {DFPPY/clay/PPY/clay}, indicating the low contribution of energy transfer. Contrarily PPY emitted exclusively from {PPY/clay/DFPPY/clay} as a result of the efficient quenching of excited DFPPY in the lower layer by PPY in the upper layer. The introduction of oxygen gas resulted in the decrease of emission for all films. Notably {DFPPY/clay/PPY/clay} exhibited a dual emitting character under an oxygen atmosphere, that is, the broad emission maximum was observed around 530 nm at lower oxygen pressure (0 < P-O2 < 4 kPa), while the emission peak shifted to 550 nm at higher oxygen pressure (P-O2 > 4 kPa).
  • Keishi Ohara, Kohji Doi, Yuka Niizaki, Shin-ichi Nagaoka
    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 249 1 - 8 1010-6030 2012/12 [Peer-reviewed]
     Scientific journal 
    A kinetic study on singlet oxygen (O-1(2)) quenching by 4-hydroxycinnamic acid derivatives (ferulic acid (FA) and caffeic acid (CA)) has been performed by measuring time-evolutions of O-1(2) phosphorescence at 1274 nm in ethanol, in an ethanol/acetone mixed solvent and in an ethanol/H2O mixed solvent under acidic, neutral and basic conditions. In organic solvents, the estimated second-order rate constants of O-1(2) quenching (k(Q)) were distributed between 10(5) and 10(6) M-1 s(-1): for example, in ethanol, 2.2 x 10(5) M-1 s(-1) for FA and 5.2 x 10(5) M-1 s(-1) for CA. On the other hand, the k(Q) values in ethanol/H2O solutions were enlarged from those in organic solvents, and varied largely with pH from 10(6) to over 10(8) M-1 s(-1). In the case of FA, the O-1(2) quenching activity decreased in the order of FA(2-) (at pH > 10)>> FA(-) (pH 5-9) > FA (pH < 4). The result suggests that deprotonation due to the acid-base equilibrium affects the O-1(2) quenching activity. For both of FA and CA, the phenolate anion under basic conditions (pH 10-12) showed the largest activity probably because of occurrence of the favored chemical quenching through the electron transfer from the phenolate anion to O-1(2). These behaviors would affect several antioxidant assays in vivo and in vitro targeting O-1(2). (C) 2012 Elsevier B.V. All rights reserved.
  • K Okada, T Terashima, A Suemitsu, I H Suzuki, S Nagaoka, K Tabayashi, Y Tamenori
    Journal of Physics: Conference Series IOP Publishing 388 (2) 022030 - 022030 1742-6588 2012/11 [Peer-reviewed]
     Scientific journal
  • Kazuo Mukai, Aya Ouchi, Shingo Takahashi, Koichi Aizawa, Takahiro Inakuma, Junji Terao, Shin-ichi Nagaoka
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 60 (32) 7905 - 7916 0021-8561 2012/08 [Peer-reviewed]
     Scientific journal 
    Measurements of the singlet oxygen (102) quenching rates (kg (S)) and the relative singlet oxygen absortpion capacity (SOAC) values were performed for 16 phenolic antioxidants (tocopherol derivatives, ubiquinol-10, caffeic acids, and catechins) and vitamin C in ethanol/chloroform/D2O (50:50:1, v/v/v) solution at 35 degrees C. It has been clarified that the SOAC method is useful to evaluate the O-1(2)-quenching activity of lipophilic and hydrophilic antioxidants having 5 orders of magnitude different rate constants from 1.38 X 10(10) M-1 s(-1) for lycopene to 2.71 X 10(5) for ferulic acid. The logarithms of the k(Q) (S) and the SOAC values for phenolic antioxidants were found to correlate well with their peak oxidation potentials (E-p); the antioxidants that have smaller E-p values show higher reactivities. In previous works, measurements of the k(Q) (S) values for many phenolic antioxidants were performed in ethanol. Consequently, measurements of the k(Q) (S) and relative SOAC values were performed for eight carotenoids in ethanol to investigate the effect of solvent on the O-1(2)-quenching rate. The k(Q) (S) values for phenolic antioxidants and carotenoids in ethanol were found to correlate linearly with the k(Q) (S) values in ethanol/chloroform/D2O solution with a gradient of 1.79, except for two catechins. As the relative rate constants (k(Q)(AO) (S)/k(Q)(alpha-Toc) (S)) of antioxidants (AO) are equal to the relative SOAC values, the SOAC values do not depend on the kinds of solvent used, if alpha-tocopherol is used as a standard compound. In fact, the SOAC values obtained for carotenoids in mixed solvent agreed well with the corresponding ones in ethanol.
  • A. Sagan, S. Nagaoka, H. Teramae, U. Nagashima
    Society of Computer Chemistry, Japan, J. Comput. Chem. Jpn. Society of Computer Chemistry, Japan 11 (2) 89 - 92 1347-1767 2012/08 [Peer-reviewed]
     Scientific journal 
    The nitrogen molecule N<sub>2</sub>has been regarded as a triple-bonded homonuclear diatomic molecule in many textbooks of physical chemistry. However, the character of the highest occupied molecular orbital HOMO (σ type or π type) is controversial in those textbooks. In this note, using RHF/6–311++G** calculation we show that the HOMO of N<sub>2</sub>is π type in the region close to the equilibrium (1.0703 Å ). In the region where the bond length is larger than 1.045 Å , the HOMO of N<sub>2</sub>is not σ type but π type.
  • Kazuo Mukai, Yutaro Kohno, Aya Ouchi, Shin-ichi Nagaoka
    JOURNAL OF PHYSICAL CHEMISTRY B 116 (30) 8930 - 8941 1520-6106 2012/08 [Peer-reviewed]
     Scientific journal 
    The measurements of the UV-vis absorption spectra of alpha-, beta-, gamma- and delta-tocopheroxyl (alpha-, beta-, gamma-, and delta-Toc(center dot)) radicals were performed by reacting aroxyl (ArO center dot) radical with alpha-, beta-, gamma- and delta-tocopherol (alpha-, beta-, gamma-, and delta-TocH), respectively, in acetonitrile solution including three kinds of alkali and alkaline earth metal salts (LiClO4, NaClO4, and Mg(ClO4)(2)) (MX or MX2), using stopped-flow spectrophotometry. The maximum wavelengths (lambda(max)) of the absorption spectra of the alpha-, beta-, gamma-, and delta-Toc(center dot) located at 425-428 nm without metal salts increased with increasing concentrations of metal salts (0-0.500 M) in acetonitrile and approached some constant values, suggesting (Toc(center dot)center dot center dot center dot M+ (or M2+)) complex formations. Similarly, the values of the apparent molar extinction coefficient (epsilon(max)) increased drastically with increasing concentrations of metal salts in ac:etonitrile and approached some constant values. The result suggests that the formations of Toc(center dot) dimers were suppressed by the metal ion complex formations of Toc' radicals. The stability constants (K) were determined for Li+, Na+, and Mg2+ complexes of alpha-, beta-, gamma-, and delta-Toc(center dot). The K values increased in the order of NaClO4 < LiClO4 < Mg(ClO4)(2), being independent of the kinds of Toc(center dot) radicals. Furthermore, the K values increased in the order of delta- < gamma < beta- < alpha-Toc(center dot) radicals for each metal salt. The alkali and alkaline earth metal salts having a smaller ionic radius of the cation and a larger charge of the cation gave a larger shift of the lambda(max) value, a larger epsilon(max) value, and a larger K value. The result of the DFT molecular orbital calculations indicated that the alpha-, beta-, gamma-, and delta-Toc(center dot) radicals were stabilized by the (1:1) complex formation with metal cations (Li+, Na+, and Mg2+). Stabilization energy (E-S) due to the complex formation increased in the order of Na+ < Li+ < Mg2+ complexes, being independent of the kinds of Toc(center dot) radicals. The calculated result also indicated that the metal cations coordinate to the O atom at the sixth position of alpha-, beta-, gamma-, and delta-Toc(center dot) radicals.
  • Computational Study of Excited-State Intramolecular-Proton-Transfer of o-Hydroxybenzaldehyde, o-Formyl-Substituted Phenols, and 5-Substituted Salicylaldehydes
    H. Teramae, S. Nagaoka, U. Nagashima
    Nova, Int. J. Chem. Modeling Nova 4 (2-3) 269 - 287 2012/03 [Peer-reviewed][Invited]
     Scientific journal
  • Kazuo Mukai, Masanori Oi, Aya Ouchi, Shin-ichi Nagaoka
    JOURNAL OF PHYSICAL CHEMISTRY B 116 (8) 2615 - 2621 1520-6106 2012/03 [Peer-reviewed]
     Scientific journal 
    A kinetic study of regeneration reaction of alpha-tocopherol (alpha-TocH) by ubiquinol-10 has been performed in the presence of four kinds of alkali and alkaline earth metal salts (LiClO4, NaClO4, NaI, and Mg(ClO4)(2)) in methanol and acetonitrile solutions, using double-mixing stopped-flow spectrophotometry. The second-order rate constants (k(r)'s) for the reaction of alpha-tocopheroxyl (alpha-Toc center dot) radical with ubiquinol-10 increased and decreased notably with increasing concentrations of metal salts in methanol and acetonitrile, respectively. The k(r) values increased in the order of no metal salt < NaClO4 similar to NaI < LiClO4 < Mg(ClO4)(2) at the same concentration of metal salts in methanol. On the other hand, in acetonitrile, the k(r) values decreased in the order of no metal salt > NaCIO4 similar to NaI > LiClO4 > Mg(ClO4)(2) at the same concentration of metal salts. The metal salts having a smaller ionic radius of cation and a larger charge of cation gave a larger k(r) value in methanol, and a smaller k(r) value in acetonitrile. The effect of anion was almost negligible in both the solvents. Notable effects of metal cations on the UV vis absorption spectrum of alpha-Toc center dot radical were observed in aprotic acetonitrile solution, suggesting complex formation between alpha-Toc center dot and metal cations. On the other hand, effects of metal cations were negligible in protic methanol, suggesting that the complex formation between alpha-Toc center dot and metal cations is hindered by the hydrogen bond between alpha-Toc center dot and methanol molecules. The difference between the reaction mechanisms in methanol and acetonitrile solutions was discussed on the basis of the results obtained. High concentrations of alkali and alkaline earth metal salts coexist with alpha-TocH and ubiquinol-10 in plasma, blood, and many tissues, suggesting the contribution of the metal salts to the above regeneration reaction in biological systems.
  • A. Sagan, S. Nagaoka, H. Teramae, U. Nagashima
    Society of Computer Chemistry, J. Comput. Chem. Jpn. 10 (4) 147 - 149 1347-1767 2011/12 [Peer-reviewed]
     Scientific journal
  • A. Sagan, U. Nagashima, T. Aoyama, S. Nagaoka
    Society of Computer Chemistry, J. Comput. Chem. Jpn. Society of Computer Chemistry, Japan 10 (3) 105 - 108 1347-1767 2011/12 [Peer-reviewed]
     Scientific journal 
    The molecular structure of alkali metal hydroxides, for example NaOH, is linear whereas the structure of H<sub>2</sub>O is bent. The main cause of the difference is analyzed by using ab initio Hartree-Fock SCF-MO calculation with 6-31G** basis set. H and OH in HOH make a highly covalent bond and the structure is bent. On the other hand, Na and OH in NaOH make a highly ionic bond like (Na<sup>+</sup>)(OH<sup>-</sup>). The Coulombic repulsion interaction between Na<sup>+</sup> and H in OH<sup>-</sup> makes the linear structure of NaOH.
  • Osamu Takahashi, Katsuyoshi Yamasaki, Shin-ichi Nagaoka, Kiyoshi Ueda
    CHEMICAL PHYSICS LETTERS 518 44 - 48 0009-2614 2011/12 [Peer-reviewed]
     Scientific journal 
    We calculated ionization potentials (IPs) to create single core-hole states and double ionization potentials (DIPs) to create double core-hole (DCH) states for a series of trihalosilyl-trimethylsilyl molecules bridged with hydrocarbons. From the calculated DIPs, IPs, and the hole-hole repulsion energies, we extracted the excess relaxation energies for the creation of DCHs at a single atomic site and interatomic relaxation energies for the creation of DCHs at two different sites. These excess and interatomic relaxation energies depend solely on the chemical environment around the atom(s) with core hole(s). We found that the interatomic relaxation is almost blocked by a dimethylene group (-CH(2)CH(2)-). (C) 2011 Elsevier B.V. All rights reserved.
  • Shin-ichi Nagaoka, Keishi Ohara, Miki Takei, Mari Nakamura, Mariko Mishima, Umpei Nagashima
    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 225 (1) 106 - 112 1010-6030 2011/12 [Peer-reviewed]
     Scientific journal 
    The UV protection and singlet-oxygen ((1)O(2)) quenching activity of intramolecularly hydrogen-bonded hydroxyanthraquinone derivatives found in aloe have been studied by means of laser spectroscopy. The UV protective activity provided by excited-state intramolecular proton-transfer (ESIFT) in these molecules correlates with their (1)O(2) quenching activity, and the UV protective molecules have high (1)O(2)-quenching function. The reason for this correlation can be understood by considering ESIPT-induced distortion of ground-state potential surfaces in encounter complexes with (1)O(2). (C) 2011 Elsevier B.V. All rights reserved.
  • A. Sagan, U. Nagashima, H. Teramae, S. Nagaoka
    Society of Computer Chemistry, Japan, J. Comput. Chem. Jpn. 10 (2) 75 - 77 1347-1767 2011/09 [Peer-reviewed]
     Scientific journal
  • Yutaro Kohno, Miyabi Fujii, Chihiro Matsuoka, Haruka Hashimoto, Aya Ouchi, Shin-ichi Nagaoka, Kazuo Mukai
    JOURNAL OF PHYSICAL CHEMISTRY B 115 (32) 9880 - 9888 1520-6106 2011/08 [Peer-reviewed]
     Scientific journal 
    The measurement of the UV-vis absorption spectrum of alpha-tocopheroxyl (alpha-Toc(center dot)) radical was performed by reacting aroxyl (ArO(center dot)) radical with alpha-tocopherol (alpha-TocH) in acetonitrile solution including four kinds of alkali and alkaline earth metal salts (MX or MX(2)) (LiClO(4), LiI, NaClO(4), and Mg(ClO(4))(2)), using stopped-flow spectrophotometry. The maximum wavelength (lambda(max)) of the absorption spectrum of the alpha-Toc(center dot) at 425.0 nm increased with increasing concentration of metal salts (0-0.500 M) in acetonitrile, and it approached constant values, suggesting an [alpha-Toc(center dot)- M(+) (or M(2+))] complex formation. The stability constants (K) were determined to be 9.2, 2.8, and 45 M(-1) for LiClO(4), NaClO(4), and Mg(ClO(4))(2), respectively. By reacting ArO(center dot) with alpha-TocH in acetonitrile, the absorption of ArO(center dot) disappeared rapidly, while that of alpha-Toc(center dot) appeared and then decreased gradually as a result of the bimolecular self-reaction of alpha-Toc(center dot) after passing through the maximum. The second-order rate constants (k(s)) obtained for the reaction of alpha-TocH with ArO(center dot) increased linearly with an increasing concentration of metal salts. The results indicate that the hydrogen transfer reaction of alpha-TocH proceeds via an electron transfer intermediate from alpha-TocH to ArO(center dot) radicals followed by proton transfer. Both the coordination of metal cations to the one-electron reduced anions of ArO(center dot) (ArO:(-)) and the coordination of counteranions to the one-electron oxidized cations of alpha-TocH (alpha-TocH(center dot+)) may stabilize the intermediate, resulting in the acceleration of electron transfer. A remarkable effect of metal salts on the rate of bimolecular self-reaction (2k(d)) of the alpha-Toc(center dot) radical was also observed. The rate constant (2k(d)) decreased rapidly with increasing concentrations of the metal salts. The 2k(d) value decreased at the same concentration of the metal salts in the following order: no metal salt > NaClO(4) > LiClO(4) > Mg(ClO(4))(2). The complex formation between alpha-Toc(center dot) and metal cations may stabilize the energy level of the reactants (alpha-Toc(center dot) + alpha-Toc(center dot)), resulting in the decrease of the rate constant (2k(d)). The alkali and alkaline earth metal salts having a smaller ionic radius of cation and a larger charge of cation gave larger K and k(s) values and a smaller 2k(d) value.
  • Shin-ichi Nagaoka, Hironobu Fukuzawa, Georg Pruemper, Mai Takemoto, Osamu Takahashi, Katsuhiro Yamaguchi, Takuhiro Kakiuchi, Kiyohiko Tabayashi, Isao H. Suzuki, James R. Harries, Yusuke Tamenori, Kiyoshi Ueda
    JOURNAL OF PHYSICAL CHEMISTRY A 115 (32) 8822 - 8831 1089-5639 2011/08 [Peer-reviewed]
     Scientific journal 
    In an aim to create a "sharp" molecular knife, we have studied site-specific fragmentation caused by Si:2p core photoionization of bridged trihalosilyltrimethylsilyl molecules in the vapor phase. Highly site-specific bond dissociation has been found to occur around the core-ionized Si site in some of the molecules studied. The site specificity in fragmentation and the 2p binding energy difference between the two Si sites depend in similar ways on the intersite bridge and the electro-negativities of the included halogen atoms. The present experimental and computational results show that for efficient "cutting" the following conditions for the two atomic sites to be separated by the knife should be satisfied. First, the sites should be located far from each other and connected by a chain of saturated bonds so that intersite electron migration can be reduced. Second, the chemical environments of the atomic sites should be as different as possible.
  • Takuhiro Kakiuchi, Narihiko Fujita, Kazuhiko Mase, Masatoshi Tanaka, Shin-ichi Nagaoka
    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 80 (8) 084703  0031-9015 2011/08 [Peer-reviewed]
     Scientific journal 
    The local valence electronic states of the surface, interface, and substrate for SiO2 ultrathin films thermally grown on a Si(100)-2x1 have been investigated using Si-L23VV Auger-electron Sin+-2p photoelectron coincidence spectroscopy (n represents the number of oxygen atoms bonded to the Si). A series of Si-L23VV Auger electron spectra (AES) measured in coincidence with Sin+-2p photoelectron indicate that the valence electronic states in the vicinity of the Sin+ sites shift to the deeper binding-energy side as n increases. Furthermore, the Si4+-L23VV AES measured as a function of the thickness of the SiO2, show that the valence-band maximum of SiO2 shifts similar to 1.6 eV toward the Fermi level when the thickness of the SiO2 film is decreased to 1.7-1.5 angstrom. This shift is attributed to a decrease in the number of Si4+ and an increase in the number of Si3+, Si2+, Si1+, and Si-0 in the vicinity of the topmost SiO2 layer.
  • K. Okada, A. Suemitsu, T. Terashima, Y. Iwasaki, Y. Tamenori, I. H. Suzuki, S. Nagaoka, K. Tabayashi
    JOURNAL OF MASS SPECTROMETRY 46 (7) 635 - 639 1076-5174 2011/07 [Peer-reviewed]
     Scientific journal 
    Total ion yield spectrum of perfluorocyclobutane (c-C4F8) has been measured in the C and F K-shell excitation regions. The peak assignments are presented based on angle-resolved photofragment ion mass spectrometry. The peaks at 291.34 and 688.5 eV are found to come from the transitions from the C 1s and the F 1s to the lowest unoccupied b(2)sigma(CF)* orbital, respectively. A photoelectron-photoion-photoion coincidence spectrum is acquired at 700.1 eV for clarifying the breakdown pathways of c-C4F82+. Two series of the pathways are identified; fission of F atom(s) followed by charge separation and elimination of CF2 or CF3 followed by charge separation. Copyright (C) 2011 John Wiley & Sons, Ltd.
  • Koichi Aizawa, Yuko Iwasaki, Aya Ouchi, Takahiro Inakuma, Shin-ichi Nagaoka, Junji Terao, Kazuo Mukai
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 59 (8) 3717 - 3729 0021-8561 2011/04 [Peer-reviewed]
     Scientific journal 
    Recently a new assay method that can quantify the singlet oxygen absorption capacity (SOAC) of antioxidants was proposed. In the present work, kinetic study of the reaction of singlet oxygen ((1)O(2)) with carotenoids and vegetable extracts has been performed in ethanol/chloroform/D(2)O (50:50:1, v/v/v) solution at 35 degrees C. Measurements of the second-order rate constants (k(Q)(S)) and the SOAC values were performed for eight kinds of carotenoids and three kinds of vegetable extracts (red paprika, carrot, and tomato). Furthermore, measurements of the concentrations of the carotenoids included in vegetable extracts were performed, using a HPLC technique. From the results, it has been clarified that the total (1)O(2)-quenching activity (that is, the SOAC value) for vegetable extracts may be explained as the sum of the product {Sigma k(Q)(Car-i)(S) [Car-i](1)} of the rate constant (k(Q)(Car-i)(S)) and the concentration ([Car (i)]) of carotenoids included in vegetable extracts.
  • K. Tabayashi, Y. Tsutsumi, M. Chohda, O. Takahashi, Y. Tamenori, I. Higuchi, I. H. Suzuki, S. Nagaoka, T. Gejo, K. Honma
    Journal of Physics: Conference Series Institute of Physics Publishing 288 012022  1742-6596 2011/04 [Peer-reviewed]
     International conference proceedings 
    Site-dependent C1s-core excitation spectra of small acetaldehyde (AAL) clusters have been studied under the cluster regime of beam conditions. The excitation spectra of the clusters were generated by monitoring the partial-ion-yields of cluster-origin fragments. Comparison of the cluster bands with the monomer bands revealed that the band intensities of C1s core-to-Rydberg transitions come to be strongly excitation-site dependent upon cluster formation showing significant reduction of C1sHCO→Ryd bands relative to the monomer bands. Computer modeling of X-ray absorption spectra using a density functional theory calculation demonstrated that the intensity reduction is the outcome of the site- and geometry-specific CH⋯O interaction where hydrogen-bonding association between the aldehyde (HCO) sites of different AAL molecules takes place exclusively within the clusters. As the representatives of small AAL clusters (n≥3), two types of molecular complexes (a planar cyclic trimer and a tetramer with a stack of two dimers) were derived to rationalize the site-dependence of the experimental C1s excitation spectra. Spectral simulation of the above complexes could reproduce the experimental site-dependence of the core-to-Rydberg band-features upon clusterization, indicative of significant contribution of these clusters under the present beam-stagnation condition.
  • Kenji Fukuzawa, Aya Ouchi, Akira Shibata, Shin-ichi Nagaoka, Kazuo Mukai
    CHEMISTRY AND PHYSICS OF LIPIDS 164 (3) 205 - 210 0009-3084 2011/03 [Peer-reviewed]
     Scientific journal 
    Vitamin E is localized in membranes and functions as an efficient inhibitor of lipid peroxidation in biological systems. In this study, we measured the reaction rates of vitamin E (alpha-, beta-, gamma-, delta-tocopherols, TocH) and tocol with aroxyl radical (ArO center dot) as model lipid peroxyl radicals in membranes by stopped-flow spectrophotometry. Egg yolk phosphatidylcholine (EYPC) vesicles were used as a membrane model. EYPC vesicles were prepared in the aqueous methanol solution (MeOH:H2O = 7:3, v/v) that gave the lowest turbidity in samples. The second-order rate constants (k(s)) for alpha-TocH in MeOH/H2O solution with EYPC vesicles were apparently 3.45 x 10(5) M-1 s(-1), which was about 8 times higher than that (4.50 x 10(4) M-1 s(-1)) in MeOH/H2O solution without EYPC vesicles. The corrected k(s) of alpha-TocH in vesicles, which was calculated assuming that the concentration of alpha-TocH was 133 times higher in membranes of 10 mM EYPC vesicles than in the bulk MeOH/H2O solution, was 2.60 x 10(3) M-1 s(-1), which was one-seventeenth that in MeOH/H2O solution because of the lower mobility of alpha-TocH in membranes. Similar analyses were performed for other vitamin E analogues. The k(s) of vitamin E in membranes increased in the order of tocol < delta-TocH < gamma-TocH similar to beta-TocH < alpha-TocH. There was not much difference in the ratios of reaction rates in vesicles and MeOH/H2O solution among vitamin E analogues [k(s)(vesicle)/k(s) (MeOH/H2O) = 7.7, 10.0, 9.5, 7.4, and 5.1 for alpha-, beta-, gamma-, delta-TocH, and tocol, respectively], but their reported ratios in solutions of micelles and ethanol were quite different [k(s)(micelle)/k(s)(EtOH) = 100, 47, 41, 15, and 6.3 for alpha-, beta-, gamma-, delta-TocH, and tocol, respectively]. These results indicate that the reaction sites of vitamin E analogues were similar in vesicle membranes but depended on hydrophobicity in micelle membranes, which increased in the order of tocol < delta-TocH < gamma-TocH similar to beta-TocH < alpha-TocH. (c) 2011 Elsevier Ireland Ltd. All rights reserved.
  • T. Kakiuchi, M. Tahara, S. Hashimoto, N. Fujita, M. Tanaka, K. Mase, S. Nagaoka
    American Physical Society, Phys. Rev. B 83 (3) 035320  2469-9950 2011/03 [Peer-reviewed]
     Scientific journal
  • I. H. Suzuki, Y. Kono, A. Ikeda, T. Ouchi, K. Ueda, O. Takahashi, I. Higuchi, Y. Tamenori, S. Nagaoka
    JOURNAL OF CHEMICAL PHYSICS 134 (8) 084312  0021-9606 2011/02 [Peer-reviewed]
     Scientific journal 
    Spectator resonant KL23L23 Auger electron spectra have been measured in the Si 1s photoexcitation region of Si(CH3)(4) using monochromatized undulator radiation combined with a hemispherical electron spectrometer. The broad peak with high intensity in a total ion yield spectrum, coming mainly from excitation of a 1s electron into the 6t(2) vacant orbital, induces a spectator Auger decay in which the excited electron remains in its excited orbital. The component on the higher energy side of this peak through 1s excitation into a Rydberg orbital produces resonant Auger decays in which the excited Rydberg electron moves into a slightly higher Rydberg orbital, or is partly shaken up to a significantly higher Rydberg orbital. These findings of Si(CH3)(4) indicate a clear contrast to those for SiF4, in which the 1s excitation into a Rydberg orbital induces a shake-down phenomenon as well as a shake-up one. The results of these molecules exhibit a clear splitting effect among excited orbitals which are smeared out by overlapping due to lifetime widths and due to densely populated levels in the 1s electron excitation spectrum. This is consistent with the calculation on photoexcitation within the framework of density functional theory. (C) 2011 American Institute of Physics. [doi:10.1063/1.3556942]
  • Keishi Ohara, Akihiro Ikeda, Shin-ichi Nagaoka
    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 218 (1) 93 - 100 1010-6030 2011/02 [Peer-reviewed]
     Scientific journal 
    The quenching kinetics of superoxide (O(2)(-center dot)) in water/oil (w/o) interface region of Aerosol OT reversed micelle has been investigated with a transient absorption method. Photodecomposition of alpha-tocopherol by 266 nm laser light in the presence of O(2) produced O(2)(-center dot) together with the tocopheroxyl radical (Toc(center dot)). The subsequent reaction between Toc(center dot) and O(2)(-center dot) occurred in the time region of 1-150 mu s after the photoexcitation. There. O(2)(-center dot) kinetics could be traced by monitoring the Toc(center dot) absorption. In an Aerosol OT reversed micelle solution containing vitamin C (VC), VC would be located in water droplets inside the reversed micelle and would react with both Toc(center dot) and O(2)(-center dot) at the w/o interface around the reversed micelle. The Toc(center dot) decay in the time region of 1-150 mu s was accelerated by addition of VC, suggesting that the O(2)(-center dot) quenching by VC progressed as well as the Tor quenching by VC. From a numerical simulation with treating the simultaneous rate equations for Toc(center dot) concentration by Runge-Kutta method, the rate constant for the O(2)(-center dot) quenching by VC could be estimated to be 6.9 x 10(7) M(-1) s(-1). This value is much larger than the corresponding value reported in homogeneous water solution, suggesting that the O(2)(-center dot) quenching by VC indeed occurred at the w/o interface of the reversed micelle. (C) 2010 Elsevier B.V. All rights reserved.
  • Hisako Sato, Kenji Tamura, Keishi Ohara, Shin-ichi Nagaoka, Akihiko Yamagishi
    NEW JOURNAL OF CHEMISTRY ROYAL SOC CHEMISTRY 35 (2) 394 - 399 1144-0546 2011/02 [Peer-reviewed]
     Scientific journal 
    The Langmuir-Blodgett films were prepared by hybridizing the clay minerals (synthetic saponite, synthetic hectorite and sodium montmorillonite)with the floating film of a cationic Ir(III) complex, [Ir(ppy)(2)(dc18bpy)](+) (ppy = 2-phenylpyridine; dc18bpy = 4,4'-dioctadecyl-2,2'-bipyridine). When the single-layered hybrid LB film was irradiated at 430 nm, it emitted light in the visible region, whose intensity responded reversibly to the pressure change of oxygen.
  • S. Nagaoka, H. Teramae, U. Nagashima
    Society of Compter Chemistry, Japan, J. Comput. Chem. Jpn. 9 (5) 241 - 248 1347-1767 2010/12 [Peer-reviewed]
     Scientific journal
  • I. H. Suzuki, Y. Kono, A. Ikeda, T. Ouchi, K. Ueda, O. Takahashi, I. Higuchi, Y. Tamenori, S. Nagaoka
    American Physical Society, Phys. Rev. A 82 (4) 045401  2469-9926 2010/10 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, H. Teramae, U. Nagashima
    Society of Computer Chemistry, Japan, J. Comput. Chem. Jpn. 9 (4) 177 - 182 1347-1767 2010/10 [Peer-reviewed]
     Scientific journal
  • Aya Ouchi, Koichi Aizawa, Yuko Iwasaki, Takahiro Inakuma, Junji Terao, Shin-ichi Nagaoka, Kazuo Mukai
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 58 (18) 9967 - 9978 0021-8561 2010/09 [Peer-reviewed]
     Scientific journal 
    A kinetic study of the quenching reaction of singlet oxygen ((1)O(2)) with eight kinds of carotenoids and alpha-tocopherol was performed in ethanol/chloroform/D(2)O (50:50:1, v/v/v) solution at 35 degrees C. The overall rate constants, k(Q) (= k(q) + k(r), physical quenching + chemical reaction), for the reaction of carotenoids with (1)O(2) were measured, using the competition reaction method, where endoperoxide was used as a singlet oxygen generator, 2,5-diphenyl-3,4-benzofuran (DPBF) as an UV-vis absorption prove, and alpha-tocopherol as a standard compound. The rate constants, k(Q) (S) and k(Q) (t(1/2)), were determined by analyzing the first-order rate constant (S) and the half-life (t(1/2)) of the decay curve of DPBF with carotenoids, respectively, showing good accordance with each other. Similar measurements were performed for tomato and carrot extracts. From the results, a new assay method that can quantify the singlet oxygen absorption capacity (SOAC) of antioxidants, including carotenoids, a-tocopherol, and vegetable extracts, has been proposed.
  • Keishi Ohara, Ryotaro Mitsumori, Mitsuharu Takebe, Daiki Kuzuhara, Hiroko Yamada, Shin-ichi Nagaoka
    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 215 (1) 52 - 58 1010-6030 2010/09 [Peer-reviewed]
     Scientific journal 
    A synthesized vitamin K model compound, NQ-6 (2-hexyloxy-1,4-naphthoquinone) showed weak fluorescence around 440 nm in ethanol. Addition of antioxidants such as vitamin E to a NQ-6 solution suppressed the NQ-6 emission quantitatively. A kinetic study on the quenching of the NQ-6 emission by hydrogen-donor type antioxidants (three tocopherol analogues, catechin, and 2,6-di-tert-butyl-4-methylphenol) in ethanol was performed. The quenching rate constant obtained from the Stern-Volmer plots for the steady-state fluorescence intensity was consistent with the second-order rate constant of each antioxidant for the free-radical scavenging. The NQ-6 emission is thought to be the delayed fluorescence caused by the thermal population to the excited singlet state from the triplet state. Thus, the fluorescence quenching occurred through a hydrogen atom transfer reaction from an antioxidant to NQ-6 in the excited triplet state ((3)NQ-6*). The second-order rate constant for the reaction between (3)NQ-6* and a-tocopherol was estimated to be 1.2 x 10(10) M(-1) s(-1) from the quenching parameter and the (3)NQ-6* lifetime in ethanol (1.2 mu s) measured with the transient absorption. From the high reactivity of (3)NQ-6* to the antioxidants and the amphiphilic property of NQ-6 as a vitamin K model, NQ-6 is applicable to the quantitative antioxidant assay as a new fluorescence probe. (C) 2010 Elsevier B.V. All rights reserved.
  • Osamu Takahashi, Isao H. Suzuki, Yutaro Kono, Akihiro Ikeda, Takao Ouchi, Kiyoshi Ueda, Itaru Higuchi, Yusuke Tamenori, Shin-Ichi Nagaoka
    Journal of Physics: Conference Series Institute of Physics Publishing 235 012018  1742-6596 2010/06 [Peer-reviewed]
     International conference proceedings 
    X-ray photo-absorption (XA) spectra of SiF4 and Si(CH 3)4 have been measured in the Si K-shell transition region using monochromatized undulator radiation and theoretical calculations have been performed within the framework of density functional theory. For SiF 4 main peak structures of the XA spectrum have been reproduced well with the calculation. Further we theoretically simulated a small peak of Si:1s→6a1 excitation, by sampling distorted geometries using classical trajectory calculations at the ground state, which is a forbidden transition under the dipole selection rule. For Si(CH3)4 only one peak was observed and reproduced well with the calculation, which was ascribed to the characteristic of broad Rydberg orbitals coupled with valence orbitals. © 2010 IOP Publishing Ltd.
  • Takuhiro Kakiuchi, Shogo Hashimoto, Narihiko Fujita, Masatoshi Tanaka, Kazuhiko Mase, Shin-ichi Nagaoka
    JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 79 (6) 064714  0031-9015 2010/06 [Peer-reviewed]
     Scientific journal 
    Valence electronic structures of a clean Si(100)-2x1 surface are investigated in a surface-site-selective way using Si-L23VV Auger electron-Si-2p photoelectron coincidence spectroscopy. The Si-L23VV Auger electron spectra measured in coincidence with Si-2p photoelectrons emitted from the Si up-atoms or Si 2nd-layer of Si(100)-2x1 suggest that the position where the highest density of valence electronic states located in the vicinity of the Si up-atoms is shifted by 0.8 eV towards lower binding energy relative to that in the vicinity of the Si 2nd-layer. Furthermore, the valence band maximum in the vicinity of the Si up-atoms is indicated to be shifted by 0.1 eV towards lower binding energy relative to that in the vicinity of the Si 2nd-layer. These results are direct evidence of the transfer of negative charge from the Si 2nd-layer to the Si up-atoms.
  • Aya Ouchi, Shin-ichi Nagaoka, Kazuo Mukai
    JOURNAL OF PHYSICAL CHEMISTRY B 114 (19) 6601 - 6607 1520-6106 2010/05 [Peer-reviewed]
     Scientific journal 
    A kinetic study of the regeneration reaction of vitamin E by ubiquinol was carried out by means of double-mixing stopped-flow spectroscopy. A substantial deuterium kinetic-isotope effect was observed on the second-order rate constant and the activation energy. In the regeneration reaction of alpha-tocopherol, deuteration of ubiquinol increased and decreased the activation energy and the second-order rate constant by 6.1 kJ/mol and a factor of 18.3, respectively. From this result, it is considered that proton tunneling plays an important role in the regeneration reaction of vitamin E by ubiquinol. The conditions under which the tunneling effect becomes an important factor were discussed in conjunction of our experimental results.
  • Takuhiro Kakiuchi, Shogo Hashimoto, Narihiko Fujita, Masatoshi Tanaka, Kazuhiko Mase, Shin-ichi Nagaoka
    SURFACE SCIENCE 604 (9-10) L27 - L30 0039-6028 2010/05 [Peer-reviewed]
     Scientific journal 
    Topmost-surface-sensitive Si-2p photoelectron spectra of a clean Si(1 0 0)-2 x 1 surface have been measured using Si-2p photoelectron Si-L(23)VV Auger coincidence spectroscopy (Si-2p-Si-L(23)VV PEACS). The escape depth of the PEACS electrons is estimated to be similar to 1.2 angstrom. The results support the assignments of the Si up-atoms, the Si down-atoms, the Si 2nd-layer, and the Si bulk proposed in previous researches. The Si-2p component with a binding energy of -0.23 eV relative to the bulk Si-2p(3/2) peak, is shown to originate mainly from the topmost surface. Site selectivity of PEACS is indicated to be achieved to some degree by carefully selecting the kinetic energy of the Auger electrons. Since PEACS can be applied to any surface, the present study opens a new approach to identify PES components. (C) 2010 Elsevier B.V. All rights reserved.
  • Keishi Ohara, Takashi Origuchi, Shin-ichi Nagaoka
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 83 (3) 246 - 253 0009-2673 2010/03 [Peer-reviewed]
     Scientific journal 
    The singlet oxygen (O-1(2)) behavior in emulsions dispersing natural vitamin E (VE) (alpha-, beta-, gamma-, and delta-tocopherols) was investigated by measuring time-profiles of O-1(2) phosphorescence. The O-1(2) rise and decay dynamics noticeably reflected the existence of VE oil-droplets. The decay rate constant (k(d)) in the a-tocopherol emulsion decreased with increase of VE concentration ([VE]), and became roughly constant in [VE] > 5 x 10(-4)M. This k(d) behavior correlated to the oil-droplet diameter measured by dynamic light scattering. The droplet diameter increased rapidly from 270 to 430 nm with increase of [VE], and reached the limit for dispersing in [VE] >= 5 x 10(-4) M. This result means that the O-1(2) surroundings became more hydrophobic with increase of droplet size. On the other hand, in the emulsions dispersing tocopherols other than alpha-tocopherol, the k(d) values were roughly constant, indicating that the oil-droplets did not contribute to O-1(2) quenching. The droplet diameter in the delta-tocopherol emulsion was around 212-243 nm and was much smaller than that in the alpha-tocopherol emulsion. The peculiar results observed in the alpha-tocopherol emulsion should be due to the large hydrophobicity of alpha-tocopherol which has two methyl-groups neighboring the OH group.
  • Keishi Ohara, Ayumi Shimizu, Yuki Wada, Shin-ichi Nagaoka
    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 210 (2-3) 173 - 180 1010-6030 2010/02 [Peer-reviewed]
     Scientific journal 
    In order to investigate effect of the inhomogeneous dispersion system on photogeneration and decay dynamics of the tocopheroxyl radical (Toc(center dot)), transient absorption and steady-state and time-resolved EPR measurements on photolysis of vitamin E (VE) were carried out. Tocopherol (TocH) is photo-decomposed through electron-detachment in the excited state and the subsequent proton releasing, which produce Toc(center dot) and the solvated electron (e(solv)(-)). The decay of Toc(center dot) is explained by (i) a rapid decay within 2 mu s by recombination between Toc(center dot) and e(solv)(-), (ii) a second-order decay observed in the range of 5-150 mu s by reaction between Toc(center dot) and the superoxide anion radical (O(2)(center dot-)), and (iii) a slow decay in >10 ms by bimolecular self-quenching of Toc(center dot). The Toc(center dot) decay in the VE emulsion was very different from that in the homogeneous solution. In the emulsion, the Toc(center dot) yield was small, the contribution of the reaction with O(2)(center dot-) was rather small, and the decay due to the bimolecular reaction of Toc(center dot) was much accelerated. In the emulsion, Toc(center dot) could not be detected by steady-state EPR, although it could in ethanol. These differences should be caused by the oil-droplet formation in the emulsion. From these results, we can expect that the photostability of the VE emulsion is superior to that of the VE homogeneous solutions. (C) 2010 Elsevier By. All rights reserved.
  • A. Ouchi, S. Nagaoka, U. Nagashima
    Society of Computer Chemistry, Japan, J. Comput. Chem. Jpn. 8 (4) 173 - 178 1347-1767 2009/12 [Peer-reviewed]
     Scientific journal
  • Keishi Ohara, Kaori Kikuchi, Takashi Origuchi, Shin-ichi Nagaoka
    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 97 (3) 132 - 137 1011-1344 2009/12 [Peer-reviewed]
     Scientific journal 
    Singlet oxygen ((1)O(2)) quenching by trolox C (TC, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), which is a water-soluble vitamin E analogue, in ethanol-water solutions and in aqueous SDS and CTAC micelles was studied by measuring the time-profiles of (1)O(2) phosphorescence at 1274 nm. The second-order rate-constant for (1)O(2) quenching by TC was determined in the ethanol-water solution to be 1.03 x 10(8), 6.22 x 10(7) and 6.23 x 10(7) M(-1) s(-1) at pH 2.0, 7.0, and 8.4, respectively. These values mean that the non-dissociated form of TC under acidic conditions has superior activity to the mono-anion form. In aqueous micelle systems, the decay rate of (1)O(2) at first decreased and then increased with increase of the concentration of TC. This behavior is explained in terms of the (1)O(2) quenching by TC in the bulk phase and in terms of shifting the environment surrounding (1)O(2) to lipophilic by dissolving TC in the hydrophobic region inside the micelle. The present investigation on (1)O(2) emission dynamics in inhomogeneous solutions made it possible to detect a little change in the solutions, which affects the environment around (1)O(2) , such as the micelle formation and dissolving solute in the micelle. (C) 2009 Elsevier B.V. All rights reserved.
  • Shin-ichi Nagaoka, Akiko Nitta, Yusuke Tamenori, Hironobu Fukuzawa, Kiyoshi Ueda, Osamu Takahashi, Takuhiro Kakiuchi, Yoshinori Kitajima, Kazuhiko Mase, Isao H. Suzuki
    JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA 175 (1-3) 14 - 20 0368-2048 2009/12 [Peer-reviewed]
     Scientific journal 
    A study on Auger-electron spectra of F3SiCH2CH2Si(CH3)(3) was performed by using monochromatized synchrotron radiation. The normal Si:L23VV Auger-electron spectrum was measured in the vapor phase and characterized through the ab initio molecular orbital calculation. The cascade Si:L23VV Auger-electron spectra were also obtained by L-23-holes creation through Si:KL23L23 Auger transitions after Si:1s photoexcitation in the vapor phase or its photoelectron emission in the condensed phase. Further the C:KVV and F:KVV Auger-electron spectra were measured and discussed in comparison with those of some related molecules. (C) 2009 Elsevier B.V. All rights reserved.
  • I. H. Suzuki, A. Nitta, H. Fukuzawa, K. Ueda, O. Takahashi, Y. Tamenori, S. Nagaoka
    JOURNAL OF CHEMICAL PHYSICS 131 (16) 164309  0021-9606 2009/10 [Peer-reviewed]
     Scientific journal 
    Excitation (total ion yield) and de-excitation (resonant photoemission) spectra have been measured in the Si 1s photoexcitation region of the F3SiCH2CH2Si(CH3)(3) molecule using monochromatized undulator radiation. Theoretical calculations within the framework of density functional theory have reproduced the observed total ion yield spectrum very well. The first peak at the lowest photon energy, coming from Si 1s excitation at the trimethyl side into a vacant orbital, induces spectator Auger decays in which the excited electron remains in its valence orbital. The second peak produced through excitation of Si 1s electron at the trifluoride side generates resonant Auger decays in which the excited valence electron remains predominantly also in the valence orbital or is partly shaken up into higher Rydberg orbitals. The third peak generated through Si 1s excitation at the trifluoride side produces resonant Auger decays in which the excited Rydberg electron remains or is partly shaken down to a lower lying valence molecular orbital. These findings exhibit a clear distinction between resonant Auger decays following photoexcitation of Si 1s electrons under different chemical environments. (C) 2009 American Institute of Physics. [doi:10.1063/1.3257639]
  • Aya Ouchi, Masaharu Ishikura, Kensuke Konishi, Shin-ichi Nagaoka, Kazuo Mukai
    LIPIDS American Oil Chemists' Society 44 (10) 935 - 943 0024-4201 2009/10 [Peer-reviewed]
     Scientific journal 
    A kinetic study of the prooxidant effect of alpha-tocopherol was performed. The rates of allylic hydrogen abstraction from various unsaturated fatty acid esters (ethyl stearate 1, ethyl oleate 2, ethyl linoleate 3, ethyl linolenate 4, and ethyl arachidonate 5) by alpha-tocopheroxyl radical in toluene were determined, using a double-mixing stopped-flow spectrophotometer. The second-order rate constants (k (p)) obtained are < 1 x 10(-2) M(-1) s(-1) for 1, 1.90 x 10(-2) M(-1) s(-1) for 2, 8.33 x 10(-2) M(-1) s(-1) for 3, 1.92 x 10(-1) M(-1) s(-1) for 4, and 2.43 x 10(-1) M(-1) s(-1) for 5 at 25.0 A degrees C. Fatty acid esters 3, 4, and 5 contain two, four, and six -CH(2)- hydrogen atoms activated by two pi-electron systems (-C=C-CH(2)-C=C-). On the other hand, fatty acid ester 2 has four -CH(2)- hydrogen atoms activated by a single pi-electron system (-CH(2)-C=C-CH(2)-). Thus, the rate constants, k (abstr)/H, given on an available hydrogen basis are k (p)/4 = 4.75 x 10(-3) M(-1) s(-1) for 2, k (p)/2 = 4.16 x 10(-2) M(-1) s(-1) for 3, k (p)/4 = 4.79 x 10(-2) M(-1) s(-1) for 4, and k (p)/6 = 4.05 x 10(-2) M(-1) s(-1) for 5. The k (abstr)/H values obtained for 3, 4, and 5 are similar to each other, and are by about one order of magnitude higher than that for 2. From these results, it is suggested that the prooxidant effect of alpha-tocopherol in edible oils, fats, and low-density lipoproteins may be induced by the above hydrogen abstraction reaction.
  • Umpei Nagashima, Shin-ichi Nagaoka
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 82 (10) 1248 - 1249 0009-2673 2009/10 [Peer-reviewed]
     Scientific journal 
    A reason for the greater chemical shift difference observed in a deep core level than a shallow level is presented.
  • Aya Ouchi, Shin-ichi Nagaoka, Kouichi Abe, Kazuo Mukai
    JOURNAL OF PHYSICAL CHEMISTRY B 113 (40) 13322 - 13331 1520-6106 2009/10 [Peer-reviewed]
     Scientific journal 
    A kinetic Study of the aroxyl (ArO.) radical-scavenging reaction of alpha-tocopherol (alpha-Toffl) has been performed in the presence of six kinds of alkali and alkaline earth metal salts (Lil, LiClO(4), Nal, NaClO(4), KI, and Mg(CIO(4))(2)) in methanol solution, using stopped-flow spectrophotometry. The decay rate of tile ArO. for tile reaction of alpha-TocH with ArO. increased linearly with increasing concentration of metal salts. The second-order rate constants (K(s)) for the reaction of a-TocH with ArO. increased in the order of no metal salt < KI similar to NaClO(4) similar to Nal < LiClO(4) < Mg(ClO(4))(2) < LiI at the same concentration of metal salts. For example, the k(s) values in methanol Solution including 4.00 x 10(-1) M of Lil and Mg(ClO(4))(2) were 3.04 and 1.30 times larger than that in the absence of metal salts, respectively. The alkali and alkaline earth metal salts having smaller ionic radius of cation and anion and larger charge of cation gave larger rate constants (Q. Effects of metal cations oil the UV-vis absorption spectra of the alpha-Toc center dot (and ArO center dot) radical were negligible in methanol solution, suggesting that the complex formation between the alpha-Toc center dot (and ArO center dot) radical molecule and metal cations is hindered by the hydrogen bond between radical and methanol molecules. The results indicate that the hydrogen transfer reaction of alpha-TocH proceeds via all electron transfer intermediate from a-TocH to ArO center dot radicals followed by proton transfer. Both the coordinations of metal cations to the one-electron reduced anions of ArO center dot (ArO: (-)) and of counteranions to the one-electron oxidized cations of alpha-TocH (alpha-TocH(+center dot)) may stabilize the intermediate, resulting in tile acceleration of electron transfer. On the other hand, the effect of metal salts on the rate of bimolecular self-reaction (2k(d)) of the alpha-Toc center dot radical was not observed. The result suggests that the hydrogen transfer reaction between two alpha-Toc center dot radical molecules proceeds via a one-step hydrogen atom transfer mechanism rather than via an electron-transfer intermediate. High concentrations of alkali and alkaline earth metal salts coexist with alpha-TocH in plasma, blood, and many tissues, suggesting the contribution of tile metal salts to the antioxidant actions of alpha-TocH.
  • Keishi Ohara, Yoko Ichimura, Shin-ichi Nagaoka
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 82 (6) 689 - 691 0009-2673 2009/06 [Peer-reviewed]
     Scientific journal 
    The second-order rate constants (k(Q)) of singlet-oxygen quenching by caffeic acid and related phenols were measured in ethanol and toluene. Caffeic acid derivatives deactivate singlet-oxygen largely by physical quenching at k(Q) = 10(6) - 10(7) M-1 s(-1) through the charge-transfer transition state.
  • I. H. Suzuki, A. Nitta, A. Shimizu, Y. Tamenori, H. Fukuzawa, K. Ueda, S. Nagaoka
    JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA 173 (1) 18 - 23 0368-2048 2009/06 [Peer-reviewed]
     Scientific journal 
    A variety of photoelectron spectra for gas phase F3SiC2H4Si(CH3)(3) molecule have been measured using monochromatized undulator radiation and a hemispherical electrostatic analyzer. Valence photoelectron spectrum shows many peaks for ionization from shallow and deep molecular orbitals in the binding energy region of 9-40eV. A calculation of ionization energies using the outer valence Green's function method indicates energies in agreement with experimental results below 17.5 eV. Spectra for Si L-shell electron emission show chemical shifts of Si atoms induced from different chemical environments around two Si atoms and also exhibit spin-orbit splitting for 2p photoelectrons. Further photoelectron spectra for C K-shell and F K-shell are discussed in comparison with those of related molecules. (C) 2009 Elsevier B.V. All rights reserved.
  • Shin-ichi Nagaoka, Hiroyuki Teramae, Umpei Nagashima
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 82 (5) 570 - 573 0009-2673 2009/05 [Peer-reviewed]
     Scientific journal 
    The excited-state intramolecular-proton-transfer of o-hydroxybenzaldehyde and its derivatives (o-formyl-substituted phenols) was studied by means of an ab initio molecular-orbital method. The computational results are consistent with the experimental fluorescence quantum yield and support the nodal-plane model. The energy difference between the ground state and the lowest excited (1)(pi,pi*) state decreases as the electron-withdrawing property of a substituent bonded to the carbonyl carbon of o-hydroxybenzaldehyde becomes stronger. However, the substituent effect does not largely distort the potential energy surface of o-formyl-substituted phenols.
  • Takuhiro Kakiuchi, Kazuo Mukai, Keishi Ohara, Shin-ichi Nagaoka
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 82 (2) 216 - 218 0009-2673 2009/02 [Peer-reviewed]
     Scientific journal 
    A study of the kinetics of the proton-transfer reaction in flavonoid in ethanol solution by means of stopped-flow spectroscopy indicated that proton tunneling plays an important role in the antioxidant reaction.
  • Aya Ouchi, Masahiko Nakano, Shin-ichi Nagaoka, Kazuo Mukai
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 57 (2) 450 - 456 0021-8561 2009/01 [Peer-reviewed]
     Scientific journal 
    Kinetic study of the aroxyl radical-scavenging action of pyrroloquinolinequinol [PQQH(2), a reduced form of pyrroloquinolinequinone (PQQ)] and water-soluble antioxidants (vitamin C, cysteine, glutathione, and uric acid) has been performed. The second-order rate constants (k(s)) for the reaction of aroxyl radical with PQQH(2) and water-soluble antioxidants were measured in Triton X-100 micellar solution (5.0 wt %) (pH 7.4), using stopped-flow and UV-visible spectrophotometers. The k(s) values decreased in the order PQQH(2) > vitamin C >> cysteine > uric acid > glutathione. The aroxyl radical-scavenging activity of PQQH(2) was 7.4 times higher than that of vitamin C, which is well-known as the most active water-soluble antioxidant. Furthermore, PQQNa(2) (disodium salt of PQQ) was easily reduced to PQQH(2) by reaction of PQQNa(2) with glutathione and cysteine in buffer solution (pH 7.4) under nitrogen atmosphere. The result suggests that PQQ exists as a reduced form throughout the cell and plays a role as antioxidant.
  • Keishi Ohara, Yoshimi Hashimoto, Chiaki Hamada, Shin-ichi Nagaoka
    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 200 (2-3) 239 - 245 1010-6030 2008/12 [Peer-reviewed]
     Scientific journal 
    The photochemical reactions of vitamin K (VK) with antioxidant vitamins (vitamin E (VE) and vitamin C (VC)) in aqueous hexadecyltrimethylammonium chloride (CTAC), sodium dodecyl sulfate (SDS), and Triton X-100 micelle systems, and in an aerosol OT (AOT) reversed micelle system were investigated by a time-resolved EPR (TR-EPR). The photolysis of VK with VE in the aqueous micelle solutions gave the TR-EPR spectra having strong intensity and net emissive polarization, suggesting that the excited triplet state of VK ((3)VK(center dot)) was rapidly quenched by VE coexisting inside the micelle. On the other hand. the photolysis of VK with VC in the aqueous SDS and CTAC micelle systems gave the spectra having weak intensity, showing that the reaction between (3)VK(center dot) and VC was inefficient in these micelle systems, probably because (3)VK(center dot) scarcely diffused Out from the micelle. The photolysis of VK with VC in the AOT reversed micelle solution gave the spin-correlated radical pair CIDEP spectrum. The result suggests that the long-lived radical pair was generated from the reaction between (3)VK(center dot) and VC in the water/oil interface region of the AOT micelle, although one of the reactants dissolved in the oil phase and another did in the separated water phase. (C) 2008 Elsevier B.V. All rights reserved.
  • S. Nagaoka, M. Takemoto, G. Prümper, H. Fukuzawa, Y. Tamenori, I. H. Suzuki, K. Ueda
    American Institute of Physics, J. Chem. Phys. 129 (20) 204309  0021-9606 2008/11 [Peer-reviewed]
     Scientific journal
  • Shuji Mitani, Aya Ouchi, Emi Watanabe, Yu Kanesaki, Shin-Ichi Nagaoka, Kazuo Mukai
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 56 (12) 4406 - 4417 0021-8561 2008/06 [Peer-reviewed]
     Scientific journal 
    Kinetic study of the aroxyl radical-scavenging action of catechins (epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), and epigallocatechin gallate (EGCG)) and related compounds (methyl gallate (MG), 4-methylcatechol (MC), and 5-methoxyresorcinol (MR)) has been performed. The second-order rate constant (k(s)) for the reaction of these antioxidants with aroxyl radical has been measured in ethanol and aqueous Triton X-100 micellar solution (5.0 wt %). The k(s) values decreased in the order of EGCG > EGC > MC > ECG > EC > MG >> MR in ethanol, indicating that the reactivity of the OH groups in catechins decreased in the order of pyrogallol B-ring > catechol B-ring > gallate G-ring > resorcinol A-ring. The structure-activity relationship in the free radical-scavenging reaction by catechins has been clarified by the detailed analyses of the pH dependence of k(s) values. From the results, the pK(a) values have been determined for catechins. The monoanion form at catechol B-and resorcinol A-rings and dianion form at pyrogallol B-and gallate G-rings show the highest activity for free radical scavenging. It was found that the free radical-scavenging activities of catechins are 3.2-13 times larger than that of vitamin C at pH 7.0.
  • K. Ohara, T. Origuchi, K. Kawanishi, S. Nagaoka
    Chemical Society of Japan, Bull. Chem. Soc. Jpn. 81 (3) 345 - 347 0009-2673 2008/03 [Peer-reviewed]
     Scientific journal
  • K. Mukai, A. Tokunaga, S. Itoh, Y. Kanesaki, A. Ouchi, K. Ohara, S. Nagaoka, K. Abe
    IOS, BioFactors IOS Press 32 (1-4) 49 - 58 1872-8081 2008 [Peer-reviewed]
     International conference proceedings
  • Shingo Itoh, Shin-Ichi Nagaoka, Kazuo Mukai
    JOURNAL OF PHYSICAL CHEMISTRY A 112 (3) 448 - 456 1089-5639 2008/01 [Peer-reviewed]
     Scientific journal 
    The rate constants (k(r)) of the regeneration reaction of 7-t-butyl-5-isopropyltocopheroxyl with ubiquinol-10 (UQ(10)H(2)), ubiquinol-0 (UQ(0)H(2)), alpha-, beta-, and gamma-tocopherolhydroquinones (alpha-, beta-, gamma-TQH(2)), 2,3,5-trimethyl-1;4-hydroquinone (TMQH(2)), vitamin K-3 hydroquinone (VK3H2), and vitamin C (Vit C) have been measured in 2-propanol/water and micellar solutions by a stopped-flow spectrophotometer. The k(r) values of these hydroquinones (HQs) in micellar solution remained constant at pHs of 6-9 and increased rapidly by increasing the pH value. The k(r) values decreased in the order of VK3H2 > gamma-TQH(2) >= alpha-TQH(2) > beta-TQH(2) >= UQ(10)H(2) >= TMQH(2) >UQ(0)H(2) >> Vit C at pHs of 6-9. These HQs are dibasic acids and can exist in three different molecular forms, depending on pH. By comparing the k(r) values with the mole fraction of each molecular form of the HQs, the reaction rate k(r1) for the undissociated form, k(r2) for the monoanion, and k(r3) for the dianion and the pK(a1) and pK(a2) values were determined. It has been found that the k(r) values of UQ(10)H(2), alpha-TQH(2), beta-TQH(2), and gamma-TQH(2) (plastoquinol model) are 460, 1430, 494, and 1530 times larger than that of Vit C at pH 7.0, respectively, although the values are similar to that of Vit C in 2-propanol/water. The biological HQs and Vit C coexist in many tissues of animals and plants, and thus, the relative antioxidant activities of HQs and Vit C have been tentatively discussed based on the products of k(r) values by concentrations in several tissues. The results suggest that these HQs show high activity for the tocopherol regeneration in biological systems.
  • G. Pruemper, X. J. Liu, H. Fukuzawa, K. Ueda, V. Carravetta, J. Harries, Y. Tamenori, S. Nagaoka
    XXV INTERNATIONAL CONFERENCE ON PHOTONIC, ELECTRONIC AND ATOMIC COLLISIONS IOP PUBLISHING LTD 88 012008  1742-6588 2007/12 [Peer-reviewed]
     International conference proceedings 
    When molecules are irradiated by x-rays complicated breakup reactions are initiated: inner shell excitation or ionization leads to a cascade of Auger decays resulting in multiple ionization and multiple bond breaks. During the last years high resolution electron ion coincidence spectroscopy has developed into a standard tool to analyse molecular break-up reaction pathways. If ion pairs or the momenta of the fragment ions are also recorded, a very detailed analysis of the break-up reaction becomes possible. A manifold of interesting processes can be studied. Here we will discuss site specific fragmentation of CH3F, F3Si-CH2-Si(CH3)(3), F3Si-CH2-CH2-Si(CH3)(3) and Cl3Si-Si(CH3)(3) and electron transfer during the break up of CH3F.
  • Shin-ichi Nagaoka, Akiko Fujii, Megumi Hino, Mai Takemoto, Misaki Yasuda, Mariko Mishima, Keishi Ohara, Akane Masumoto, Hidemitsu Uno, Umpei Nagashima
    JOURNAL OF PHYSICAL CHEMISTRY B 111 (45) 13116 - 13123 1520-6106 2007/11 [Peer-reviewed]
     Scientific journal 
    The UV protection and singlet oxygen quenching of aloesaponarin I have been studied by means of laser spectroscopy. The excited-state intramolecular proton transfer that provides the UV protection takes place along only one of the molecule's two intramolecular hydrogen bonds, and this can be understood by considering the nodal pattern of the wave function. The functional groups participating in the excited-state intramolecular proton transfer also play important roles in the singlet oxygen quenching. Aloesaponarin I has a quenching rate constant larger than that of vitamin E and has a long duration of action due to its resistance to UV degradation and chemical attacks by singlet oxygen and free radicals.
  • K. Mukai, T. Isozaki, S. Nagaoka
    Chemical Society of Japan, Bull. Chem. Soc. Jpn. 80 (7) 1331 - 1334 0009-2673 2007/07 [Peer-reviewed]
     Scientific journal
  • Shin-ichi Nagaoka, Takuhiro Kakiuchi, Keishi Ohara, Kazuo Mukai
    CHEMISTRY AND PHYSICS OF LIPIDS ELSEVIER IRELAND LTD 146 (1) 26 - 32 0009-3084 2007/03 [Peer-reviewed]
     Scientific journal 
    The rate constant and activation energy of the regeneration reaction of natural vitamin E by vitamin C were determined with a double-mixing stopped-flow spectrophotometer. The formation of vitamin C radical was observed in the absorption spectrum. The kinetic effect of methyl substitution on the aromatic ring of vitamin E radical indicates that partial charge-transfer plays a role in the reaction. Since a substantial deuterium kinetic isotope effect was not found, the tunneling effect may not play an important role under the present experimental conditions. (c) 2007 Elsevier Ireland Ltd. All rights reserved.
  • T. Ibuki, S. Itoh, Y. Tamenori, K. Okada, S. Nagaoka, Y. Morishita, I. H. Suzuki
    JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA 154 (3) 53 - 59 0368-2048 2007/02 [Peer-reviewed]
     Scientific journal 
    Atomic-like Auger electron emission was observed in resonant excitation of F1s electron into the sigma*(CSF) molecular orbital of CF3SF5. This finding means that an S-F bond forming the C-S-F linear skeleton in the ground state dissociates in the order of femto-seconds. The Auger electron emitted from the F atom showed a Doppler shift by using angle-resolved photoelectron spectroscopy. Asymmetry parameter for the leaving F atom relative to the linearly polarized electric vector was deduced to be beta = 1.9 at high photon energy of 688.7 eV and a value of beta = 1.1 by detuning the photon energy down to 686.8 eV. The variation of P on the exciting energies projects a profile that an axial recoil approximation effectively works for the ultrafast S-F dissociation when the F1s-(1)sigma,*s, state is generated at high energy level on the sigma*(CSF), potential curve but retardation effects between the F and CF3SF4 fragments become noticeable at low energy level where kinetic energy of the F atom gets smaller. (c) 2006 Elsevier B.V. All rights reserved.
  • S. Nagaoka, G. Prümper, H. Fukuzawa, M. Hino, M. Takemoto, Y. Tamenori, J. Harries, I. H. Suzuki, O. Takahashi, K. Okada, K. Tabayashi, X.-J. Liu, T. Lischke, K. Ueda
    American Physical Society, Phys. Rev. A 75 (2) 020502(R)  2469-9926 2007/02 [Peer-reviewed]
     Scientific journal
  • Kazuo Mukai, Aiko Tokunaga, Shingo Itoh, Yu Kanesaki, Keishi Ohara, Shin-ichi Nagaoka, Kouichi Abe
    JOURNAL OF PHYSICAL CHEMISTRY B 111 (3) 652 - 662 1520-6106 2007/01 [Peer-reviewed]
     Scientific journal 
    The reaction rates (k(s)) of vitamin E (alpha-, beta-, gamma-, delta-tocopherols, TocH), ubiquinol-10, and related antioxidants (tocol, ubiquinol-0, and hydroquinone) with aroxyl (ArO center dot) radical have been measured in micellar solution by stopped-flow spectrophotometer. The k(s) values increased in the order of hydroquinone < tocol < delta-TocH < ubiquinol-0 < gamma-TocH approximate to beta-TocH < ubiquinol-10 < alpha-TocH at pH 4 similar to 8. The antioxidants which have lower oxidation potentials showed higher reactivities. The k(s) values of alpha-, beta-, gamma-, delta-tocopherol, and tocol remained constant between pH 4 and 10, and decreased rapidly at pH 11 similar to 12 by increasing pH value. From the pH dependence of k(s) values, the pK(a) values (= 13.1 similar to 12.6) have been determined for these tocopherols. The k(s) values of ubiquinol-10 also remained constant between pH 4 and 9, and increased rapidly at pH 9.5. Ubiquinol-10 is dibasic acid and can exist in three different molecular forms, depending on the pH value. By comparing the k(s) values with the mole fraction of each molecular form of ubiquinol-10, the reaction rate k(s1) (= 1.21 x 10(5) M(-1)s(-1)) for the undissociated form, k(s2) (= 1.04 x 10(6) M(-1)s(-1)) for monoanion and k(s3) (= 0 M (-1)s (-1)) for dianion, and the pK(a1) and pK(a2) values (= 11.4 and 12.7) were determined. The k(s2) value is 8.6 times as large as the k(s1) value. Similar analyses were performed for ubiquinol-0 and hydroquinone. It was found that the relative ratio of k(s) values (100:21:20:2.9) of alpha-, beta-, gamma-, delta-tocopherols in micellar dispersion has good correlation with the relative biopotency ratios for rat fetal resorption, rat hemeolysis, and chicken muscle dystrophy. The relative antioxidant activities of alpha-tocopherol and ubiquinol-10 have been discussed based on the k(s) values obtained and their concentrations in serum and several tissues (heart, muscle, liver, kidney, and brain).
  • Hironobu Fukuzawa, Georg Prumper, Shin-ichi Nagaoka, Toshio Buki, Yusuke Tamenori, James Harries, XiaoJing Liu, Kiyoshi Ueda
    CHEMICAL PHYSICS LETTERS 431 (4-6) 253 - 256 0009-2614 2006/11 [Peer-reviewed]
     Scientific journal 
    We have studied site-specific fragmentation caused by F 1s photoionization of free CF3SF5 molecules. Energy-resolved electrons and mass-resolved ions were detected in coincidence. We found an enhancement of the CF3+ ion production in coincidence with photoelectrons emitted from F atoms in the SF5 group due to a reaction path leading to CF+-SF+ pair production. We found an enhancement of the CF+ and C+ ions due to F Is electron emission from the CF3 group. Site-selectivity was also observed for the CF+-SF+, CF+-SF+, CF+-SF+, C+-F+, C+-S+ and C+-SF+ ion pair production (c) 2006 Elsevier B.V. All rights reserved.
  • Kiyohiko Tabayashi, Keisuke Yamamoto, Osamu Takahashi, Yusuke Tamenori, James R. Harries, Tatsuo Gejo, Mitsuhiro Iseda, Takashi Tamura, Kenji Honma, Isao H. Suzuki, Shin-ichi Nagaoka, Toshio Ibuki
    JOURNAL OF CHEMICAL PHYSICS 125 (19) 194307  0021-9606 2006/11 [Peer-reviewed]
     Scientific journal 
    Inner-shell excitation spectra and fragmentation of small clusters of formic acid have been studied in the oxygen K-edge region by time-of-flight fragment mass spectroscopy. In addition to several fragment cations smaller than the parent molecule, we have identified the production of HCOOH center dot H(+) and H(3)O(+) cations characteristic of proton transfer reactions within the clusters. Cluster-specific excitation spectra have been generated by monitoring the partial ion yields of the product cations. Resonance transitions of O1s(C = O/OH) electrons into pi(*)(CO) orbital in the preedge region were found to shift in energy upon clusterization. A blueshift of the O1s(C = O)->pi(*)(CO) transition by similar to 0.2 eV and a redshift of the O1s(OH)->pi(*)(CO) by similar to 0.6 eV were observed, indicative of strong hydrogen-bond formation within the clusters. The results have been compared with a recent theoretical calculation, which supports the conclusion that the formic-acid clusters consist of the most stable cyclic dimer and/or trimer units. Specifically labeled formic acid-d, HCOOD, was also used to examine the core-excited fragmentation mechanisms. These deuterium-labeled experiments showed that HDO(+) was formed via site-specific migration of a formyl hydrogen within an individual molecule, and that HD(2)O(+) was produced via the subsequent transfer of a deuterium atom from the hydroxyl group of a nearest-neighbor molecule within a cationic cluster. Deuteron (proton) transfer from the hydroxyl site of a hydrogen-bond partner was also found to take place, producing deuteronated HCOOD center dot D(+) (protonated HCOOH center dot H(+)) cations within the clusters. (c) 2006 American Institute of Physics.
  • Keishi Ohara, Yoko Ichimura, Kumi Tsukamoto, Mayumi Ogata, Shin-ichi Nagaoka, Kazuo Mukai
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 79 (10) 1501 - 1508 0009-2673 2006/10 [Peer-reviewed]
     Scientific journal 
    A kinetic study involving 4-hydroxycinnamic acid derivatives (HCAs) was performed in order to clarify the mechanism for free radical-scavenging and vitamin E-regenerating. The second-order rate constants of the radical-scavenging reaction (k(s)) observed for caffeic acid derivatives are larger than those for ferulic acid derivatives. The result may be explained by i) the lower oxidation potential coming from the existence of the more electron-donating hydroxy group comparing with methoxy group, and ii) the stabilization effect of the corresponding radicals produced in the radical-scavenging reaction through intramolecular hydrogen bonding. The radical-scavenging activity of HCAs in ethanol mainly occurs via the hydrogen atom transfer from the phenolic OH-protons. The pH dependence of k(s) for ferulic acid in the aqueous Triton X-100 micelle solutions suggests the importance of the phenolic OH proton on the radical-scavenging reaction. On the other hand, the pH dependence of k(s) for caffeic acid and chlorogenic acid suggests the occurrence of intramolecular hydrogen bonding and an electron-transfer process in the radical-scavenging reaction.
  • T Ibuki, Y Tamenori, K Okada, M Takemoto, S Nagaoka, Y Morishita, IH Suzuki
    JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA 152 (1-2) 96 - 99 0368-2048 2006/06 [Peer-reviewed]
     Scientific journal 
    Ionization energies for valence electrons of CF3SF5 were measured in the 12-35 eV region by means of angle-resolved photoelectron spectroscopy. The observed ionization energies were basically consistent with previous ones measured by threshold photoelectron and HeI photoelectron spectroscopy, and the ionization levels at 22.60, 26.92 and 27.86 eV were newly observed. Asymmetry parameter derived at hv = 684.7 eV was a constant of beta = 1.02 +/- 0.04 in the ionization energy lower than 20 eV, suggesting that lone pair electron of F atom is probably released through 2p -> epsilon d like electron emission. Characters of the 22 valence bands were elucidated with the help of ab initio calculations and of the nature of valence orbitals for CF4 and SF6. (c) 2006 Elsevier B.V. All rights reserved.
  • Shin-ichi Nagaoka, Umpei Nagashima, Joji Ohshita
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 79 (4) 537 - 548 0009-2673 2006/04 [Peer-reviewed]
     Scientific journal 
    A detailed examination of the relationship between chemical shifts in ESCA (electron spectroscopy for chemical analysis) and NMR (nuclear magnetic resonance) is presented for two silicon sites of bridged trichlorosilyl-trimethylsilyl molecules [Cl3Si-CnHm-Si(CH3)(3) (n = 0-5 and m = 0-10)]. It is shown that the ESCA chemical shift of a silicon site mainly depends on the electronic environment within a mean radius of 1.168 angstrom of the nucleus and the NMR chemical shift depends on the electronic environment within a radius of more than 1.875 angstrom.
  • S Nagaoka, A Tamura, A Fujii, J Ohshita, K Okada, T Ibuki, IH Suzuki, H Ohashi, Y Tamenori
    INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 247 (1-3) 101 - 105 1387-3806 2005/12 [Peer-reviewed]
     Scientific journal 
    Ionic fragmentation caused by Si: 1s photoexcitation of 1-trifluorosilyl-2-trimethylsil yl ethane [F3SiCH2CH2Si(CH3)(3)] vapor was studied using monochromatized synchrotron radiation and a reflectron-type mass spectrometer. The total ion-yield spectrum in the Si: Is excitation region was found to be very similar to the superposition of the ion-yield spectra of Si(CH3)(4) and SiF4, showing that site-specific excitation occurred in this molecule. When the photon energy was scanned from low to high, the 1s -> sigma(*) excitation at the Si atom bonded to three CH3 groups suppressed the production of CH3+ and SiCH3+. The 1s -> sigma(*) excitation at the Si atom bonded to three F atoms, on the other hand, enhanced the production of F+ and SiF+ and suppressed the production of SiF3+. These results suggest that Si: 1s site-specific excitation causes site-specific fragmentation. The fragmentation caused by Si: 1s -> sigma(*) photoexcitation was also found to be more violent than that caused by Si:2p -> sigma(*) photoexcitation. (c) 2005 Elsevier B.V. All rights reserved.
  • S Nagaoka, K Mase
    SURFACE SCIENCE 593 (1-3) 276 - 282 0039-6028 2005/11 [Peer-reviewed]
     Scientific journal 
    We used the energy-selected-photoelectron photoion coincidence method, the resonance-Auger-electron photoion coincidence method and monochromatized synchrotron-radiation to study ion desorption caused by N 1s core-level photoexcitation of nitrous oxide (N2O) condensed and physisorbed on a Si(1 0 0) surface. The site-specificity was kept during the resonant Auger processes, that is, within the N 1s core-hole lifetime. However, the site-specific ion desorption was not clearly revealed, though some site-specificity had been reported in the vapor phase. The origin of the disappearance of the site-specificity was discussed in detail. (c) 2005, Elsevier B.V. All rights reserved.
  • K. Mukai, S. Noborio, S. Nagaoka
    Wiley, Int. J. Chem. Kinet. 37 (10) 605 - 610 1097-4601 2005/10 [Peer-reviewed]
     Scientific journal
  • S Nagaoka, Y Tamenori, M Hino, T Kakiuchi, J Ohshita, K Okada, T Ibuki, IH Suzuki
    CHEMICAL PHYSICS LETTERS 412 (4-6) 459 - 463 0009-2614 2005/09 [Peer-reviewed]
     Scientific journal 
    Ionic fragmentation caused by Si: Is photoionization of 1-trifluorosilyl-2-trimethylsilyiethane [F3SiCH2CH2 Si(CH3)(3)] vapor was studied by the energy-selected photoclectron photoion coincidence method and monochromatized synchrotron radiation. In the Is photoionization at the Si atom bonded to three F atoms, H+ exceeded the other ions in the peak height, and production of SiF3+ ion seemed to be reduced. On the other hand, the Is photoionization at the other Si atom bonded to three CH3 groups enhanced production of H+ ion with high kinetic energy. These results suggest that Si:1s photoionization causes site-specific fragmentation. (c) 2005 Elsevier B.V. All rights reserved.
  • T Ibuki, Y Shimada, R Hashimoto, S Nagaoka, M Hino, K Okada, IH Suzuki, Y Morishita, Y Tamenori
    CHEMICAL PHYSICS 314 (1-3) 119 - 126 0301-0104 2005/07 [Peer-reviewed]
     Scientific journal 
    Photodecomposition of K-shell excited CF3SF5 was investigated by means of photoelectron-photoion coincidence (PEPICO) and photoion-photoion coincidence (PIPICO) spectroscopy. In PEPICO mode to study site-selective fragmentation, the yield of CF3+ was high at the Cls -> sigma(CS)* excitation and that of SF3+ was considerable at the excitation into sigma(CF)*. When the F K-shell of SF5 was selectively excited, the formation of CF3+ was prominent. The atomic ions of S+ and F+ were overwhelmingly produced with some amounts of S2+ and S3+ ions at the S K-shell excitation. Formation of highly charged CF3SF5n+ (n = 2-4) ions was con firmed by PIPICO spectroscopy. The yields of CF3SF5n+ (n = 3,4) were low at the S1s -> sigma(*)(SF), excitation. Breakdown pathways of the CF3SF5n+ ions were discussed. (c) 2005 Elsevier B.V. All rights reserved.
  • K Okada, Y Yamana, T Ibuki, A Fujii, S Nagaoka, K Tabayashi, Y Shimada, Y Morishita, Y Tamenori, IH Suzuki, K Ohno
    JOURNAL OF ELECTRON SPECTROSCOPY AND RELATED PHENOMENA ELSEVIER SCIENCE BV 144-147 187 - 189 0368-2048 2005/06 [Peer-reviewed]
     Scientific journal 
    Photoabsorption cross-sections of CF2CH2 were measured in the carbon K-edge region and linear time-of-flight mass spectra were acquired at some photon energies across the two pi* peaks. The kinetic energy distributions of CH2+ and CF2+ with two components were deduced from the analysis of the mass spectra. The CH2+ ion with high kinetic energies increases with the extent of vibrational excitation of the C-F 1s -> pi* state, indicating that molecular vibrations play an important role in the photofragmentation of the inner-shell excited molecule. (c) 2005 Elsevier B.V. All rights reserved.
  • K Mukai, S Mitani, K Ohara, SI Nagaoka
    FREE RADICAL BIOLOGY AND MEDICINE 38 (9) 1243 - 1256 0891-5849 2005/05 [Peer-reviewed]
     Scientific journal 
    The reaction rates (k(r)) of 5,7-diisopropyl-tocopheroxyl radical (Toc(center dot)) with catechins (epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC), epigoallocatechin gallate (EGCG)) and related compounds (methyl gallate (MG), 4-methyleatechol (MC), and 5-Foethoxyresorcinol (MR)) have been measured by stopped-flow spectrophotorneter. The k(r), values increased in the order of MR << MG < EC < MC similar to ECG < FGC < EGCG in ethanol and 2-propanol/H2O (5/1, v/v) solutions, indicating that the reactivity of the OH groups in catechins increased in the order of resorcinol A-ring << gallate G-ring < catechol B-ring < pyrogallol B-ring. The catechins which have lower oxidation potentials show higher reactivities. The rate constants for catechins in micellar solution showed notable pH dependence with one or two peaks around pH 9-11, because of the dissociation of various phenolic hydroxyl protons in catechins. The Structure-activity relationship in the free-radical-scaveril-ing reaction by catechins has been clarified by the detailed analyses of the pH dependence of kr values. The reaction rates increased remarkably with increasing the anionic character of catechins, that is, the electron-donating capacity of catechins. The mono anion form at catechol B-and resorcinol A-rings and dianion form at pyrogallol B-and gallate G-rings show the highest activity for free-radical-scavenging. It was found that catechins (EC, ECG, EGC, and EGCG) have activity similar to or higher than that of vitamin C in vitamin E regeneration at pH 7-12 in micellar solution. (c) 2005 Elsevier Inc. All rights reserved.
  • K Ohara, W Mizukami, A Tokunaga, S Nagaoka, H Uno, K Mukai
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 78 (4) 615 - 621 0009-2673 2005/04 [Peer-reviewed]
     Scientific journal 
    A kinetic Study was performed for the free-radical scavenging actions of curcumin and half-curcumin, which has a half-structure of curcumin, in order to clarify the mechanism of free-radical-scavenging in curcumin. The second-order rate constants for radical-scavenging reactions of curcumin and half-curcumin were measured by a stopped-flow spectrophotometer in several organic solvents (methanol, ethanol, acetonitrile, chloroform, and benzene) and in aqueous Triton X-100 (5.0 wt %) micelle solutions at various pH. The difference in the rate constant and solvent dependence between curcumin and half-curcumin suggests that the enol structure with the intramolecular hydrogen-bond Of Curcumin strongly enhances the radical-scavenging activity. Furthermore, notable pH dependences were observed for the rate constants of curcumin and half-curcumin in micelle solutions, suggesting that the acid-base dissociation equilibrium of phenol-protons in curcumin and half-curcumin affects their radical-scavenging activities.
  • K Okada, M Kosugi, A Fujii, S Nagaoka, T Ibuki, S Samori, Y Tamenori, H Ohashi, IH Suzuki, K Ohno
    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 38 (4) 421 - 431 0953-4075 2005/02 [Peer-reviewed]
     Scientific journal 
    Resonant Auger transitions into (1)G(4)(.)nl states following Kr 2p(3/2) electron excitation have been measured using monochromatized undulator radiation and a hemispherical electron energy analyser. A clear identification of electron peaks was made for (1)G(4)(.)5s, (1)G(4)(.)4d, (1)G(4)(.)5d and so forth when the photon energy approached the ionization threshold. The fort-nation of the (1)G(4)(.)4d state was found over a relatively wide energy range across the threshold, because of the short lifetime of the 2p hole and of shake effects in electron emission processes. The angular dependence of these decays showed little effect on the polarization direction of the incident photon, which suggests that little anisotropy is related to that of the normal Auger transition into the (1)G(4) state.
  • S Tanaka, K Mase, S Nagaoka
    SURFACE SCIENCE 572 (1) 43 - 58 0039-6028 2004/11 [Peer-reviewed]
     Scientific journal 
    We used electron-ion coincidence spectroscopy to investigate the photostimulated ion-desorption from clean and water-chemisorbed TiO2 (110) and ZnO (10 (1) over bar0). Desorption of O+ from TiO2 ( 10) and ZnO (10 (1) over bar0) surfaces and that of H+ from water-chemisorbed TiO2 (110) and ZnO(10 (1) over bar0) surfaces were observed after O1s-excitaion. These are not due to the two-hole final state caused by the ordinal single-electron excitation and its normal Auger decay but mainly due to the n-hole (n > 2) final state which was provided by the multiple excitation/decay of the O1s electron. After metal-core excitation, meanwhile, ion (O+ and H+) desorption is observed from the clean and water-chemisorbed TiO2 (110) surfaces, but, not observed from clean or water-chemisorbed ZnO (10 (1) over bar0) surfaces. The ion desorption following the metal-core excitation cannot be fully explained by a similar mechanism to the KF model where the interatomic Auger decay prov'ides the change of the charging state of the oxygen. We therefore propose a new mechanism in which the charge trar sfer from the O2p orbital to the Ti3d orbital is induced by the Ti3d core hole potential and is responsible for the creation and desorption of the O+ ions. (C) 2004 Elsevier B.V. All rights reserved.
  • T Ibuki, Y Shimada, S Nagaoka, A Fujii, M Hino, T Kakiuchi, K Okada, K Tabayashi, T Matsudo, Y Yamana, IH Suzuki, Y Tamenori
    CHEMICAL PHYSICS LETTERS 392 (4-6) 303 - 308 0009-2614 2004/07 [Peer-reviewed]
     Scientific journal 
    Total photoabsorption cross-sections of trifluoromethyl sulfur pentafluoride, CF3SF5, were measured in the C, F and S K-shell regions by using a double ionization chamber and synchrotron radiation at the SPring-8 facility. The maximum cross sections were found to be 6.3, 5.0 and 1.1 Mb for the C, F and S K-edges, respectively. The spectral features in the F K-shell region were characterized by the photoabsorption spectra of CF4 and SF6 and those in the S K-shell region resemble the peaks of SF6. The observed peaks for CF3SF5 were tentatively assigned on the basis of a comparison with those for CF4 and SF6 measured simultaneously for references. (C) 2004 Elsevier B.V. All rights reserved.
  • IH Suzuki, A Fujii, S Nagaoka, M Kosugi, K Okada, T Ibuki, S Samori, Y Tamenori, H Ohashi
    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 37 (7) 1433 - 1441 0953-4075 2004/04 [Peer-reviewed]
     Scientific journal 
    Asymmetric and broadened peaks for the 2p(3/2) photoelectron and normal Auger electrons of L3M45M45 decays in Kr have been measured using monochromatized undulator radiation and a hemispherical electron energy analyser. Just above the ionization threshold, the photoelectron shows a tailing into lower energies and the normal Auger line of the (1)G(4) final state exhibits a tailing into higher energies. This finding that the tailings mirror each other originates from the post-collision interaction effect; that is, the slower photoelectron is overtaken by the normal Auger electron. Away from the threshold the tailing width and the shift of the Auger peak decrease, approaching a Lorentzian peak structure.
  • Y Tamenori, K Okada, S Tanimoto, T Ibuki, S Nagaoka, A Fujii, Y Haga, IH Suzuki
    JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS 37 (1) 117 - 129 0953-4075 2004/01 [Peer-reviewed]
     Scientific journal 
    Multiple-charged Kr ions have been studied using monochromatized synchrotron radiation combined with a coincidence technique. The multiple-charged ions formed through ionization of the inner sub-shells were detected by a time-of-flight mass analyser and the photoelectrons emitted from those orbitals were observed by a cylindrical mirror electron energy analyser. The coincidence measurement between the energy-selected photoelectron and the photoion specified the individual multiple ionization channels of Kr. The Kr 3d ionization produces doubly and triply charged ions. The Kr 3p ionization mainly yields triply charged Kr ions via M23M45N23 Coster-Kronig decays, and the M23M45N1 decays generate considerably quadruply charged ions. The 3s ionization significantly produces quadruply charged ions via super-Coster-Kronig decays with successive Auger transitions.
  • K Ohara, R Watanabe, Y Mizuta, S Nagaoka, K Mukai
    JOURNAL OF PHYSICAL CHEMISTRY B 107 (41) 11527 - 11533 1520-6106 2003/10 [Peer-reviewed]
     Scientific journal 
    The photoinitiated reaction between vitamin C and xanthone in sodium lauryl sulfate (SDS), hexadecyltrimethylammonium chloride (CTAC), and Triton X-100 micelle solutions at various pH was investigated by time-resolved electron paramagnetic resonance (TR-EPR). The TR-EPR spectra were explained by superimpositions of the xanthone ketyl and the vitamin C radicals, showing that a fast hydrogen abstraction reaction of the excited xanthone from vitamin C progresses around the water-oil interface region of the micelles. The EPR signal intensity of the vitamin C radical showed the notable pH dependence, which seems to be attributable to the acid-base dissociation equilibrium of vitamin C. The results suggested that the present reaction is controlled by the transportation of the excited xanthone and vitamin C to the reaction-progressing region, which is the surface or inside of the micelle, and by the difference of the reactivity between the dissociation forms of vitamin C.
  • Kouji Isari, Hiroaki Yoshida, Tatsuo Gejo, Eiichi Kobayashi, Kazuhiko Mase, Shin-Ichi Nagaoka, Kenichiro Tanaka
    Shinku/Journal of the Vacuum Society of Japan Vacuum Society of Japan 46 (5) 377 - 384 0559-8516 2003/05 [Peer-reviewed]
     Scientific journal 
    We have developed a coaxially symmetric mirror electron energy analyzer with a high sensitivity, which was originally proposed by Kai Siegbahn in 1997. The analyzer, however, had a weak point i.e. the performance is degraded by disturbance of the electric field near the end plates. We have improved the point by adopting compensation electrodes. Simulation with SIMION 3D version 7.0 predicts that the energy resolution (E/ΔE, FWHM) would be 300 for a pointed electron source and a solid angle of 1.2 sr. This value is about 3 times as much as the predicted value for the cylindrical mirror analyzer (CMA) used in previous EICO apparatuses. The resolution of the electron energy analyzer was obtained at UVSOR BL-2B1 by measuring an Au:4f photoelectron spectrum of a gold film. The actual energy resolution was evaluated to be 110-130. Some improvements and applications to coincidence spectroscopy are also described.
  • M Nagao, S Nagaoka, S Tanaka, K Mukai, Y Yamashita, J Yoshinobu
    SURFACE SCIENCE 529 (3) 288 - 294 0039-6028 2003/04 [Peer-reviewed]
     Scientific journal 
    The adsorbed states of 1,1,1-trifluoro-2-propanol (TFIP) molecule on Si(100) c(4 x 2) have been investigated by high resolution electron energy loss spectroscopy. TFIP is dissociatively adsorbed on Si(100) as CF3CH(O-Si)CH3 and H-Si at 100 K. These species are stable up to 300 K. At 400 K, CF bonds start to be dissociated. At 800 K, all adsorbed species are decomposed into SiH, SiF, SiF2 and residual carbon species. At 1050 K, the silicon carbide is formed. (C) 2003 Elsevier Science B.V. All rights reserved.
  • S. Nagaoka, A. Nakamura, U. Nagashima
    Elsevier, J. Photochem. Photobiol. A 154 (1) 23 - 32 1010-6030 2002/12 [Peer-reviewed][Invited]
     Scientific journal
  • S Tanaka, K Mase, S Nagaoka, M Nagasono, M Kamada
    JOURNAL OF CHEMICAL PHYSICS 117 (9) 4479 - 4488 0021-9606 2002/09 [Peer-reviewed]
     Scientific journal 
    This work is an investigation of the desorption by O 1s excitation of ions from Si(100) reacted with water. Photoelectron, photostimulated desorption, and electron-ion coincidence spectroscopy are used to observe the process. When the incident photons have energy levels which are near the 1s threshold of O, they induce Auger decay that is accompanied by shakeup/off excitation and cascade Auger decay, and they are shown to be the main factor responsible for desorption in this case. When the photons have energy levels which are above the shakeup threshold, most of the desorption that occurs is a result of the shakeup excitation that accompanies the core excitation. In both cases, the desorption is induced by the respective multihole final states. The ion desorption yield for the two-hole final states of the normal process of Auger decay is small. The results are discussed, with the help of the Auger electron spectra, mainly in terms of the lifetime of the final state of Auger decay. (C) 2002 American Institute of Physics.
  • S Nagaoka, K Mase, A Nakamura, M Nagao, J Yoshinobu, S Tanaka
    JOURNAL OF CHEMICAL PHYSICS 117 (8) 3961 - 3971 0021-9606 2002/08 [Peer-reviewed]
     Scientific journal 
    We used the energy-selected-photoelectron photoion coincidence (ESPEPICO) method to study site-specific fragmentation caused by C:1s photoionization of 1,1,1-trifluoro-2-propanol-d(1) [CF(3)CD(OH)CH(3), TFIP-d(1)] on a Si(100) surface. High-resolution electron energy loss spectroscopy showed that TFIP-d(1) is dissociatively chemisorbed like (CF(3))(CH(3))CDO-Si(100), and different chemical shifts at the three carbon sites were observed by photoelectron spectroscopy. The site-specific fragmentation evident in the ESPEPICO spectra of the sub-monolayer at room temperature indicates that the TFIP-d(1) there has an O-Si bond oriented in the trans position with respect to the C-CF(3) bond. Here we discuss the fragmentation processes in light of the results obtained with the ESPEPICO method and the Auger-electron photoion coincidence method. (C) 2002 American Institute of Physics.
  • Y. Tamenori, K. Okada, S. Nagaoka, T. Ibuki, S. Tanimoto, Y. Shimizu, A. Fujii, Y. Haga, H. Yoshida, H. Ohashi, I. H. Suzuki
    Institute of Physics, J. Phys. B 35 (12) 2799 - 2809 0953-4075 2002/06 [Peer-reviewed]
     Scientific journal
  • T Ibuki, K Okada, K Kamimori, J Sasaki, H Yoshida, A Hiraya, IH Suzuki, N Saito, S Nagaoka, H Ohashi, Y Tamenori
    SURFACE REVIEW AND LETTERS 9 (1) 85 - 88 0218-625X 2002/02 [Peer-reviewed]
     Scientific journal 
    Auger electron spectra were studied by scanning the photon energy near the L-3 threshold of krypton. Two resonant transitions were observed in the photon energy region 1673-1678 eV for the first time. They were identified to be the resonant 3d(-2)5s and 3d(-2)4d states originating in the 2p(3/2)(-1)5s and 2P(3/2)(-1)4d excitations, respectively.
  • I. H. Suzuki, K. Okada, K. Kamimori, J. Sasaki, H. Yoshida, A. Hiraya, Y. Shimizu, S. Nagaoka, Y. Tamenori, H. Ohashi, T. Ibuki
    World Scientific, Surf. Rev. Lett. 9 (1) 63 - 67 0218-625X 2002/02 [Peer-reviewed]
     International conference proceedings
  • S. Nagaoka, T. Fujibuchi, J. Ohshita, U. Nagashima, I. Koyano
    Elsevier, Chem. Phys. 276 (3) 243 - 256 0301-0104 2002/02 [Peer-reviewed]
     Scientific journal
  • K. Ueda, H. Yoshida, Y. Senba, K. Okada, Y. Shimizu, H. Chiba, H. Ohashi, Y. Tamenori, H. Okumura, N. Saito, S. Nagaoka, A. Hiraya, E. Ishiguro, T. Ibuki, I. H. Suzuki, I. Koyano
    Elsevier, Nucl. Instrum. Methods A 467-468 1502 - 1504 0168-9002 2001/07 [Peer-reviewed]
     International conference proceedings
  • H. Ohashi, E. Ishiguro, Y. Tamenori, H. Okumura, A. Hiraya, H. Yoshida, Y. Senba, K. Okada, N. Saito, I. H. Suzuki, K. Ueda, T. Ibuki, S. Nagaoka, I. Koyano, T. Ishikawa
    Elsevier, Nucl. Instrum. Methods A 467-468 533 - 536 0168-9002 2001/07 [Peer-reviewed]
     International conference proceedings
  • Y. Nishioku, K. Ohara, K. Mukai, S. Nagaoka
    American Chemical Society, J. Phys. Chem. B 105 (21) 5032 - 5038 1089-5647 2001/05 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, S. Tanaka, K. Mase
    American Chemical Society, J. Phys. Chem. B American Chemical Society 105 (8) 1554 - 1561 1089-5647 2001/03 [Peer-reviewed]
     Scientific journal
  • N. Saito, K. Ueda, M. Simon, K. Okada, Y. Shimizu, H. Chiba, Y. Senba, H. Okumura, H. Ohashi, Y. Tamenori, S. Nagaoka, A. Hiraya, H. Yoshida, E. Ishiguro, T. Ibuki, I. H. Suzuki, I. Koyano
    American Physical Society, Phys. Rev. A 62 (4) 042503  2469-9926 2000/10 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, T. Ibuki, N. Saito, Y. Shimizu, Y. Senba, K. Kamimori, Y. Tamenori, H. Ohashi, I. H. Suzuki
    Institute of Physics, J. Phys. B 33 (17) L605 - L610 0953-4075 2000/09 [Peer-reviewed]
     Scientific journal
  • K. Okada, K. Ueda, T. Tokushima, Y. Senba, H. Yoshida, Y. Shimizu, M. Simon, H. Chiba, H. Okumura, Y. Tamenori, H. Ohashi, N. Saito, S. Nagaoka, I. H. Suzuki, E. Ishiguro, I. Koyano, T. Ibuki, A. Hiraya
    Elsevier, Chem. Phys. Lett. 326 (3/4) 314 - 320 0009-2614 2000/08 [Peer-reviewed]
     Scientific journal
  • S. Tanaka, K. Mase, M. Nagasono, S. Nagaoka, M. Kamada
    Elsevier, Surf. Sci. 451 (1/3) 182 - 187 0039-6028 2000/04 [Peer-reviewed]
     Scientific journal
  • K. Mase, S. Tanaka, S. Nagaoka, T. Urisu
    Elsevier, Surf. Sci. 451 (1/3) 143 - 152 0039-6028 2000/04 [Peer-reviewed]
     Scientific journal
  • H. Uno, K. Kasahara, N. Nibu, S. Nagaoka, N. Ono
    American Chemical Society, J. Org. Chem. 65 (6) 1615 - 1622 0022-3263 2000/03 [Peer-reviewed]
     Scientific journal
  • S. Tanaka, K. Mase, M. Nagasono, S. Nagaoka, M. Kamada, E. Ikenaga, T. Sekitani, K. Tanaka
    Japan Society of Applied Physics, Jpn. J. Appl. Phys. 39 (7B) 4489 - 4492 0021-4922 2000 [Peer-reviewed][Invited]
     Scientific journal
  • S. Nagaoka, M. Inoue, C. Nishioka, Y. Nishioku, S. Tsunoda, C. Ohguchi, K. Ohara, K. Mukai, U. Nagashima
    American Chemical Society, J. Phys. Chem. B 104 (4) 856 - 862 1089-5647 2000/01 [Peer-reviewed]
     Scientific journal
  • K. Ohara, S. Nagaoka, K. Mukai
    Chemical Society of Japan, Bull. Chem. Soc. Jpn. 73 (1) 37 - 42 0009-2673 2000/01 [Peer-reviewed]
     Scientific journal
  • S Nagaoka, K Mase, M Nagasono, S Tanaka, T Urisu, J Ohshita, U Nagashima
    CHEMICAL PHYSICS 249 (1) 15 - 27 0301-0104 1999/10 [Peer-reviewed]
     Scientific journal 
    We used photoelectron spectroscopy and the energy-selected-photoelectron photoion coincidence (ESPEPICO) method to study site-specific phenomena in the Si:2p photoionization of X3Si(CH2)(n)Si(CH3)(3) (X = F or Cl, n = 0-2) condensed on a Si(111) surface. The site-specific excitation and the occurrence of different chemical shifts at two Si sites were revealed in the total electron-yield spectra and the photoelectron spectra of F3Si(CH2)(n)Si(CH3)(3) (n = 1, 2), although they were not clearly revealed in those of Cl3SiSi(CH3)(3). We conclude that these site-specific phenomena are easily observed in molecules in which the two Si sites are located far apart and in which electron migration between the two Si-containing groups does not occur. This was supported by our ab initio calculation. Site-specific fragmentation was revealed in the ESPEPICO spectrum of F3SiCH2CH2Si(CH3)(3), although it was negligible for Cl3SiSi(CH3)(3) and was less remarkable in F3SiCH2Si(CH3)(3) than in F3SiCH2CH2Si(CH3)(3). Site-specific fragmentation also occurred when the two Si sites were located far apart. (C) 1999 Elsevier Science B.V. All rights reserved.
  • H. Tomoda, K. Kitajima, M. Nakai, S. Yamamoto, S. Nagaoka
    Japan Society for Precision Engineering, J. Jpn. Soc. Precision Eng. 精密工学会 65 (6) 851 - 856 0912-0289 1999/06 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, J. Kusunoki, T. Fujibuchi, S. Hatakenaka, K. Mukai, U. Nagashima
    Elsevier, J. Photochem. Photobiol. A 122 (3) 151 - 159 1010-6030 1999/03 [Peer-reviewed]
     Scientific journal
  • K. Sawada, S. Onodera, H. Enomoto, S. Nagaoka, K. Mukai
    Chemical Society of Japan, J. Chem. Soc. Jpn. (3) 169 - 176 0369-4577 1999/03 [Peer-reviewed]
     Scientific journal
  • K Sawada, S Onodera, H Enomoto, S Nagaoka, K Mukai
    KOBUNSHI RONBUNSHU 56 (5) 298 - 306 0386-2186 1999 [Peer-reviewed]
     Scientific journal 
    Three kinds of spin label compounds having a DOXYL-radical substituent at different positions df the hydrocarbon chain of stearic acid were added to the poly(vinyl chloride) (PVC) including dioctyl phthalate (DOP) as plasticizer, and the order parameter (S) of each radical in PVC resin was determined by the ESR measurement. The values of S which is a parameter of dynamic state of spin label compounds in PVC decreased by increasing the quantity of DOP added to PVC. Similarly, the values of S decreased by increasing the temperature. The decrease of S may be explained by the, decrease of rigidity of PVC resin, due to the addition of DOP and the increase of the temperature. The half-decrease temperature of the order parameter (T-S1/2) for each radical decreased by increasing the quantity of DOP added to PVC and by decreasing the density (d) and the glass transition temperature (T-g) of PVC resin. The stable structures for each interaction model (PVC/stearic acid additive model, PVC/DOP model) were estimated by molecular orbital (MO) calculation.
  • S Nagaoka, K Mukai, U Nagashima
    JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM ELSEVIER SCIENCE BV 455 (2-3) 199 - 203 0166-1280 1998/12 [Peer-reviewed][Invited]
     Scientific journal 
    The ab initio method has been applied to investigate the magnetic properties of 1,1',5,5'-tetramethyl-6,6'-dithioxo-3,3'-biverdazyl homo-biradical and 3-(2',6'-di-t-butyl-4'-phenoxyl)-1,5-dimethyl-6-thioxoverdazyl hetero-biradical. The second order Moller-Plesett perturbation method for the restricted open-shell wavefunctions and the method of Borden and Davidson are very useful to predict the magnetic properties of homo- and hetero-biradicals. (C) 1998 Elsevier Science B.V. All rights reserved.
  • S. Nagaoka, Y. Nishioku, K. Mukai
    Elsevier, Chem. Phys. Lett. 287 (1/2) 70 - 74 0009-2614 1998/04 [Peer-reviewed]
     Scientific journal
  • K. Mukai, M. Nuwa, K. Suzuki, S. Nagaoka, N. Achiwa, J. B. Jamali
    American Chemical Society, J. Phys. Chem. B AMER CHEMICAL SOC 102 (5) 782 - 787 1089-5647 1998/01 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, T. Fujibuchi, J. Ohshita, M. Ishikawa, I. Koyano
    Elsevier, Int. J. Mass Spectrom. Ion Processes 171 (1/3) 95 - 103 0168-1176 1997/12 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, K. Mase, M. Nagasono, S. Tanaka, T. Urisu, J. Ohshita
    American Institute of Physics, J. Chem. Phys. 107 (24) 10751 - 10755 0021-9606 1997/12 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, S. Yamamoto, K. Mukai
    Elsevier, J. Photochem. Photobiol. A 105 (1) 29 - 33 1010-6030 1997/05 [Peer-reviewed]
     Scientific journal
  • K. Mukai, W. Oka, K. Watanabe, Y. Egawa, S. Nagaoka, J. Terao
    American Chemical Society, J. Phys. Chem. A 101 (20) 3746 - 3753 1089-5639 1997/05 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, Y. Shinde, K. Mukai, U. Nagashima
    American Chemical Society, J. Phys. Chem. 101 (17) 3061 - 3065 1089-5639 1997/04 [Peer-reviewed]
     Scientific journal
  • K. Mase, M. Nagasono, S. Tanaka, T. Urisu, S. Nagaoka
    Elsevier, Surf. Sci. 377/379 376 - 379 0039-6028 1997/04 [Peer-reviewed]
     International conference proceedings
  • Shin-Ichi Nagaoka, Kazuhiko Ishihara
    Journal of the American Chemical Society 118 (31) 7361 - 7366 0002-7863 1996/08 [Peer-reviewed]
     Scientific journal 
    Photoinduced electron transfer (ET) of the model vitamin E-duroquinone system (MVE-D) has been investigated by means of femtosecond spectroscopy. The interaction between the vitamin E and duroquinone moieties is not extensive in the ground state, and the charge-transfer band is not clearly seen in the absorption spectrum. The bonding of vitamin E to duroquinone largely reduces the lifetime of the lowest excited singlet state (S1 state) of duroquinone owing to ET from the vitamin E moiety to the duroquinone moiety. Since the S1 state [(n,π*) state] of duroquinone is regarded as a model for the peroxyl radical, the reduction of the lifetime is direct microscopic observation of the initial stage in the corresponding part of the antioxidant process of vitamin E. It is considered that the photoinduced ET of MVE-D corresponds to the inverted regime. The vibrational modes of the product reduce the lifetime by opening ET vibronic channels which have small barriers.
  • S. Nagaoka, U. Nagashima
    Elsevier, Chem. Phys. 206 (3) 353 - 362 0301-0104 1996/06 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, T. Fujibuchi, U. Nagashima, S. Kato, K. Takano, I. Koyano
    Elsevier, J. Electron Spectrosc. Relat. Phenom. 79 499 - 502 0368-2048 1996/05 [Peer-reviewed]
     International conference proceedings
  • Y. Kohno, Y. Egawa, S. Itoh, S. Nagaoka, M. Takahashi, K. Mukai
    Elsevier, Biochim. Biophys. Acta 1256 (1) 52 - 56 0005-2728 1995/04 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, J. Ohshita, M. Ishikawa, K. Takano, U. Nagashima, T. Takeuchi, I. Koyano
    American Institute of Physics, J. Chem. Phys. 102 (15) 6078 - 6087 0021-9606 1995/04 [Peer-reviewed]
     Scientific journal
  • S. Itoh, S. Nagaoka, K. Mukai, S. Ikesu, Y. Kaneko
    American Oil Chemists' Society, Lipids 29 (11) 799 - 802 0024-4201 1994/11 [Peer-reviewed]
     Scientific journal
  • K. Mukai, S. Ohbayashi, S. Nagaoka, T. Ozawa, N. Azuma
    Chemical Society of Japan, Bull. Chem. Soc. Jpn. 66 (12) 3808 - 3810 0009-2673 1993/12 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, A. Itoh, K. Mukai, U. Nagashima
    American Chemical Society, J. Phys. Chem. 97 (44) 11385 - 11392 0022-3654 1993/11 [Peer-reviewed]
     Scientific journal
  • M. Mimuro, Y. Nishimura, S. Takaichi, Y. Yamano, M. Ito, S. Nagaoka, I. Yamazaki, T. Katoh, U. Nagashima
    Elsevier, Chem. Phys. Lett. 213 (5/6) 576 - 580 0009-2614 1993/10 [Peer-reviewed]
     Scientific journal
  • K. Mukai, T. Tamaki, S. Kawasaki, S. Nagaoka
    Gordon and Breach Science, Mol. Cryst. Liq. Cryst. Gordon and Breach Science 233 (1) 1 - 8 1542-1406 1993/09 [Peer-reviewed]
     International conference proceedings
  • K. Mukai, H. Morimoto, Y. Okauchi, S. Nagaoka
    American Oil Chemists' Society, Lipids 28 (8) 753 - 756 0024-4201 1993/08 [Peer-reviewed]
     Scientific journal
  • Kinetic Study of Free-Radical-Scavenging Action of Biological Hydroquinones (Reduced Forms of Ubiquinone, Vitamin K and Tocopherol Quinone)in Solution
    K. Mukai, H. Morimoto, S. Kikuchi, S. Nagaoka
    Elsevier, Biochim. Biophys. Acta Elsevier 1157 (2) 313 - 317 0304-4165 1993/06 [Peer-reviewed]
     Scientific journal
  • M MIMURO, U NAGASHIMA, S NAGAOKA, S TAKAICHI, YAMAZAKI, I, Y NISHIMURA, T KATOH
    CHEMICAL PHYSICS LETTERS 204 (1-2) 101 - 105 0009-2614 1993/03 [Peer-reviewed]
     Scientific journal 
    The forbidden singlet excited (2(1)Ag) state of a linear carotenoid, neurosporene, in solution was directly detected by a single-photon absorption spectrum at 20-degrees-C. The absorption maximum in n-hexane was located at 623 +/- 2 nm with its extinction coefficient of about 60 and an oscillator strength of 3.4 X 10(-4). This is the first identification of the S1 state of long polyenes by the single-photon absorption spectroscopy, which leads to understanding of the excited state of polyenes by using parameters directly obtained by absorption spectrum.
  • S. Nagaoka, J. Ohshita, M. Ishikawa, T. Masuoka, I. Koyano
    American Chemical Society, J. Phys. Chem. 97 (8) 1488 - 1495 0022-3654 1993/02 [Peer-reviewed]
     Scientific journal
  • S. Akiyama, S. Yamauchi, N. Hirota, S. Nagaoka
    American Chemical Society, J. Phys. Chem. 97 (1) 40 - 45 0022-3654 1993/01 [Peer-reviewed]
     Scientific journal
  • S NAGAOKA, K MUKAI, T ITOH, S KATSUMATA
    JOURNAL OF PHYSICAL CHEMISTRY AMER CHEMICAL SOC 96 (20) 8184 - 8187 0022-3654 1992/10 [Peer-reviewed]
     Scientific journal 
    A photoelectron spectroscopic study and ab initio calculations of the antioxidant action of vitamin E derivatives have been carried out. The vertical ionization energies (I(v)'s) of tocopherols (TocH's) were obtained by using photoelectron spectroscopy. The geometries of TocH's were optimized, and the Koopmans' theorem first ionization energies (I(K)'s) for those geometries were calculated with the ab initio method. A plot of I(K) vs I(v) is found to be linear. The second-order rate constant for the reaction of TocH with a substituted phenoxyl radical (k(s)) increases and the activation energy (E(act) decreases as I(v) (I(K)) decreases. A plot of E(act), vs I(v) (I(K)) is found to be linear. A substantial deuterium kinetic isotope effect on k(s) is also observed. It is thus considered that both the charge transfer and the proton tunneling play important roles in the antioxidant reaction of TocH.
  • K. Mukai, Y. Uemoto, M. Fukuhara, S. Nagaoka, K. Ishizu
    Chemical Society of Japan, Bull. Chem. Soc. Jpn. 65 (8) 2016 - 2020 0009-2673 1992/08 [Peer-reviewed]
     Scientific journal
  • S NAGAOKA, K SAWADA, Y FUKUMOTO, U NAGASHIMA, S KATSUMATA, K MUKAI
    JOURNAL OF PHYSICAL CHEMISTRY AMER CHEMICAL SOC 96 (16) 6663 - 6668 0022-3654 1992/08 [Peer-reviewed]
     Scientific journal 
    To shed light on the mechanism of proton-transfer reactions, a kinetic, spectroscopic, and ab initio study of the prooxidant action of vitamin E derivatives has been carried out. The second-order rate constants (k(-s)'s) for the reaction of six tocopheroxyl radicals (Toc.'s) with five alkyl hydroperoxides (ROOHs) in benzene were determined spectrophotometrically. The first adiabatic ionization potentials (I(a)'s) of ROOHs were obtained by means of photoelectron spectroscopy. The result indicates that k(-s) increases as the electron-donating capacity of the alkyl substituents of ROOH increases and I(a) decreases. The methylation at the aromatic ring of Toc. reduces the k(-s) for a given ROOH. k(-s) for the reaction of deuterated alkyl hydroperoxides (ROODs) with a Toc. in a mixed solution of benzene and ethanol-d1 was also measured. A deuterium kinetic isotope effect on k(-s) is observed. For a given Toc., plots of log k(-s) vs I(a) for various ROOHs and log k(-s) vs Tafts sigma* constant of alkyl substituents of ROOH are found to be linear. The slope of the plot of log k(-s) vs sigma* for ROOD is similar to that for ROOH. The geometries of ROOHs were optimized, and the Koopmans' theorem first ionization potentials (I(K)'s) for those geometries were calculated with the ab initio method. A plot of log k(-s)the reactions of a Toc. with various ROOHs vs I(K) of the ROOH is also found to be linear. From these results, it is considered that both charge transfer and proton tunneling play important roles in the prooxidant reaction of TocH. The transition state in the prooxidant reaction has properties of the charge-transfer species. The proton tunneling takes place below the transition state. Tunneling allows the proton to cut a corner on the potential energy surface. Our explanation will be widely applicable to many transfer reactions.
  • Investigation of the Lowest Excited Triplet States of 2-(2'- Hydroxyphenyl)benzothiazole and 2-(2'-Hydroxyphenyl)benzoxazole by Time-Resolved Electron Paramagnetic Resonance and Molecular Orbital Calculations
    S. Nagaoka, A. Itoh, K. Mukai, E. Hoshimoto, N. Hirota
    Elsevier, Chem. Phys. Lett. 192 (5/6) 532 - 537 0009-2614 1992/05 [Peer-reviewed]
     Scientific journal
  • M MIMURO, U NAGASHIMA, S NAGAOKA, Y NISHIMURA, S TAKAICHI, T KATOH, YAMAZAKI, I
    CHEMICAL PHYSICS LETTERS 191 (3-4) 219 - 224 0009-2614 1992/04 [Peer-reviewed]
     Scientific journal 
    The solvent effect on the fluorescence quantum yields of S1 (PHI(1)) and S2 (PHI(2)) states of carotenoids containing a keto group is examined. The relative yields (PHI(2)/PHI(1)) are expressed exponentially as a function of the reciprocal of the dielectric constants of several non-polar solvents. This relationship can be explained by the energy gap law of internal conversion from the second excited state of carotenoids. This leads to the first quantitative study of solvent effects on the relaxation process of carotenoids.
  • S. Nagaoka, A. Kuranaka, H. Tsuboi, U. Nagashima, K. Mukai
    American Chemical Society, J. Phys. Chem. 96 (6) 2754 - 2761 0022-3654 1992/03 [Peer-reviewed]
     Scientific journal
  • E. Hoshimoto, S. Yamauchi, N. Hirota, S. Nagaoka
    American Chemical Society, J. Phys. Chem. 95 (25) 10229 - 10235 0022-3654 1991/12 [Peer-reviewed]
     Scientific journal
  • A. Kuranaka, S. Sawada, U. Nagashima, S. Nagaoka, K. Mukai
    Vitamin Society of Japan, Vitamins 65 (9) 453 - 458 1991/09 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, I. Koyano, T. Imamura, T. Masuoka
    John Wiley & Sons, Appl. Organomet. Chem. 5 (4) 269 - 276 0268-2605 1991/07 [Peer-reviewed][Invited]
     Scientific journal
  • S. Nagaoka, U. Nagashima
    American Chemical Society, J. Phys. Chem. 95 (10) 4006 - 4008 0022-3654 1991/05 [Peer-reviewed]
     Scientific journal
  • U. Nagashima, S. Nagaoka, S. Katsumata
    American Chemical Society, J. Phys. Chem. 95 (9) 3532 - 3538 0022-3654 1991/05 [Peer-reviewed]
     Scientific journal
  • S NAGAOKA, Y OKAUCHI, S URANO, U NAGASHIMA, K MUKAI
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY AMER CHEMICAL SOC 112 (24) 8921 - 8924 0002-7863 1990/11 [Peer-reviewed]
     Scientific journal
  • K. Ueda, Y. Sato, S. Nagaoka, I. Koyano, A. Yagishita, T. Hayaishi
    Elsevier, Chem. Phys. Lett. 170 (4) 389 - 395 0009-2614 1990/07 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, U. Nagashima
    American Chemical Society, J. Phys. Chem. 94 (11) 4467 - 4469 0022-3654 1990/05 [Peer-reviewed]
     Scientific journal
  • Shin-ichi Nagaoka, Inosuke Koyano, Toshio Masuoka
    Physica Scripta Institute of Physics 41 (4) 472 - 474 1402-4896 1990/04 [Peer-reviewed]
     Scientific journal 
    Dissociation processes following double photoionization of Al(CH3)3have been studied in the range of valence and Al: 2p core-level ionization by means of the photoelectron-photoion and photoion-photoion coincidence methods. The double-ionization threshold and the Al: 2p core-ionization threshold are estimated to be about 30 and 80eV, respectively. The variation of the fragmentation pattern with photon energy is discussed in conjunction with the relevant electronic states. The relative yields of the H+-Al+and H+-CHm+(m' = 0-3) ion pairs are enhanced around the Al: 2p core-ionization threshold. © 1990 IOP Publishing Ltd.
  • M UKAI, K KAMETA, K SHINSAKA, Y HATANO, T HIRAYAMA, S NAGAOKA, K KIMURA
    CHEMICAL PHYSICS LETTERS 167 (4) 334 - 340 0009-2614 1990/03 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, S. Suzuki, U. Nagashima, T. Imamura, I. Koyano
    American Chemical Society, J. Phys. Chem. 94 (6) 2283 - 2290 0022-3654 1990/03 [Peer-reviewed]
     Scientific journal
  • K. Ueda, E. Shigemasa, Y. Sato, S. Nagaoka, I. Koyano, A. Yagishita, T. Hayaishi
    Elsevier, Chem. Phys. Lett. 166 (4) 391 - 396 0009-2614 1990/03 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, U. Nagashima
    American Chemical Society, J. Phys. Chem. 94 (4) 1425 - 1431 0022-3654 1990/02 [Peer-reviewed]
     Scientific journal
  • Kiyoshi Ueda, Eiji Shigemasa, Yukinori Sato, Shin-ichi Nagaoka, Inosuke Koyano, Akira Yagishita, Tatsuji Hayaishi
    Physica Scripta Institute of Physics 41 (1) 78 - 82 1402-4896 1990/01 [Peer-reviewed]
     Scientific journal 
    Ionic fragmentation following the photoionization of Sn(CH3)4 (TMT) has been studied in the photon energy range of 60-600 eV using synchrotron radiation and time-of-flight mass spectrometry. Each of the Sn: 4d, 4p, 3d and C: 1s photoionization leads to a type of ionic fragmentation that is characteristic of each ionized core. The Sn: 4d photoionization above 60 eV predominantly produces the doubly-charged TMT which dissociates into two singly-charged ions and some neutral fragments. The ions produced in this pathway are CH3 +, C2H3 +, C2H5 +, SnCHm + and/or Sn+. The Sn: 4p photoionization produces the triply-charged TMT and enhances the production of H+, CHm' + (m' = 0-3) and Sn+ significantly. The Sn: 3d photoionization produces multiply-charged TMT whose charges are 3-5 and enhances the production of H+, CHm' + (m' = 0-2) and Sn+ significantly. The C: 1s photoionization produces doubly-charged TMT via the KVV Auger transition and enhances the production of CH3 +, C2H3 +, SnCHm + and/or Sn+. © 1990 IOP Publishing Ltd.
  • S. Nagaoka, U. Nagashima
    Elsevier, Chem. Phys. 136 (2) 153 - 163 0301-0104 1989/09 [Peer-reviewed][Invited]
     Scientific journal
  • S. Nagaoka, S. Suzuki, U. Nagashima, T. Imamura, I. Koyano
    American Institute of Physics, Rev. Sci. Instrum. 60 (7 Pt.2B) 2201 - 2204 0034-6748 1989/07 [Peer-reviewed]
     International conference proceedings
  • H. Shiromaru, H. Suzuki, H. Sato, S. Nagaoka, K. Kimura
    American Chemical Society, J. Phys. Chem. 93 (5) 1832 - 1835 0022-3654 1989/03 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, I. Koyano, K. Ueda, E. Shigemasa, Y. Sato, A. Yagishita, T. Nagata, T. Hayaishi
    Elsevier, Chem. Phys. Lett. 154 (4) 363 - 368 0009-2614 1989/01 [Peer-reviewed]
     Scientific journal
  • K. Ueda, E. Shigemasa, Y. Sato, S. Nagaoka, I. Koyano, A. Yagishita, T. Nagata, T. Hayaishi
    Elsevier, Chem. Phys. Lett. 154 (4) 357 - 362 0009-2614 1989/01 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, S. Suzuki, I. Koyano
    Elsevier, Nucl. Instrum. Methods A 266 (1/3) 699 - 703 0168-9002 1988/04 [Peer-reviewed]
     International conference proceedings
  • S. Nagaoka, U. Nagashima, N. Ohta, M. Fujita, T. Takemura
    American Chemical Society, J. Phys. Chem. 92 (1) 166 - 171 0022-3654 1988/01 [Peer-reviewed]
     Scientific journal
  • Shin-ichi Nagaoka
    Journal of Photochemistry Elsevier 40 (1) 185 - 188 0047-2670 1987/09 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, S. Suzuki, I. Koyano
    American Physical Society, Phys. Rev. Lett. 58 (15) 1524 - 1527 0031-9007 1987/04 [Peer-reviewed]
     Scientific journal
  • T. Takemura, M. Fujita, S. Nagaoka
    Elsevier, Chem. Phys. Lett. 130 (1/2) 39 - 42 0009-2614 1986/09 [Peer-reviewed]
     Scientific journal
  • S. Suzuki, S. Nagaoka, I. Koyano, K. Tanaka, T. Kato
    Springer-Verlag, Z. Phys. D 4 (1) 111 - 119 0178-7683 1986/03 [Peer-reviewed][Invited]
     Scientific journal
  • S. Nagaoka, T. Takemura, H. Baba, N. Koga, K. Morokuma
    American Chemical Society, J. Phys. Chem. 90 (5) 759 - 763 0022-3654 1986/02 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, E. T. Harrigan, M. Noda, N. Hirota, J. Higuchi
    Chemical Society of Japan, Bull. Chem. Soc. Jpn. 59 (2) 355 - 361 0009-2673 1986/02 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, M. Fujita, T. Takemura, H. Baba
    Elsevier, Chem. Phys. Lett. 123 (6) 489 - 492 0009-2614 1986/01 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, T. Takemura, H. Baba
    Chemical Society of Japan, Bull. Chem. Soc. Jpn. 58 (7) 2082 - 2087 0009-2673 1985/07 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, N. Hirota, M. Sumitani, K. Yoshihara, E. Lipczynska-Kochany, H. Iwamura
    American Chemical Society, J. Am. Chem. Soc. 106 (23) 6913 - 6916 0002-7863 1984/11 [Peer-reviewed]
     Scientific journal
  • M. Noda, S. Nagaoka, N. Hirota
    Chemical Society of Japan, Bull. Chem. Soc. Jpn. 57 (9) 2376 - 2382 0009-2673 1984/09 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, T. Terao, F. Imashiro, N. Hirota, S. Hayashi
    Elsevier, Chem. Phys. Lett. 108 (5) 524 - 525 0009-2614 1984/07 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, N. Hirota
    Chemical Society of Japan, Bull. Chem. Soc. Jpn. 56 (11) 3381 - 3389 0009-2673 1983/11 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, T. Terao, F. Imashiro, A. Saika, N. Hirota, S. Hayashi
    American Institute of Physics, J. Chem. Phys. 79 (10) 4694 - 4703 0021-9606 1983/11 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, N. Hirota, M. Sumitani, K. Yoshihara
    American Chemical Society, J. Am. Chem. Soc. 105 (13) 4220 - 4226 0002-7863 1983/06 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, N. Hirota, T. Matsushita, K. Nishimoto
    Elsevier, Chem. Phys. Lett. 92 (5) 498 - 502 0009-2614 1982/11 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, T. Terao, F. Imashiro, A. Saika, N. Hirota, S. Hayashi
    Elsevier, Chem. Phys. Lett. 80 (3) 580 - 584 0009-2614 1981/06 [Peer-reviewed]
     Scientific journal
  • S. Nagaoka, N. Hirota
    American Institute of Physics, J. Chem. Phys. 74 (3) 1637 - 1644 0021-9606 1981/02 [Peer-reviewed]
     Scientific journal
  • N. Hirota, M. Baba, Y. Hirata, S. Nagaoka
    American Chemical Society, J. Phys. Chem. 83 (26) 3350 - 3354 0022-3654 1979/12 [Peer-reviewed][Invited]
     Scientific journal

Books etc

  • ビタミンE研究の進歩XVII
    長岡伸一, 高橋京香, 中村明日香, 小原敬士, 向井和男 (Contributor, ビタミンEの一重項酸素消去速度に及ぼす金属塩の効果)
    ビタミンE研究会 2016/12 148 53-56
  • 愛媛大学「研究室からこんにちは!」7
    長岡伸一 (Contributor, 科学者の夢である分子用ナイフの研究や寿命を左右する活性酸素の消去法を探る)
    アトラス出版 2013/07 9784906885091 433 316-332
  • ビタミンE研究の進歩XV
    福澤健治, 柴田瑩, 大内綾, 長岡伸一, 向井和男 (Contributor, 卵黄レシチンリポソーム膜におけるビタミンEのラジカル消去反応速度)
    ビタミンE研究会 2012/12 155 152-153
  • ビタミンE研究の進歩ⅩⅣ(1)
    大内綾, 長岡伸一, 向井和男 (Contributor, ユビキノールによるビタミンEラジカル再生反応におけるトンネル効果)
    ビタミンE研究会 2010/12 1-6
  • ビタミンE研究の進歩ⅩⅣ(2)
    大内綾, 長岡伸一, 阿部皓一, 向井和男 (Contributor, ビタミンEのラジカル消去反応に及ぼすアルカリ及びアルカリ土類金属塩の効果)
    ビタミンE研究会 2010/12 51-56
  • ビタミンE研究の進歩ⅩⅣ(3)
    大内綾, 石倉正治, 小西健介, 長岡伸一, 向井和男 (Contributor, α-Tocopherolの酸化促進効果の速度論的研究:α-Tocopheroxylラジカルによる脂質の水素引き抜き反応速度の測定)
    ビタミンE研究会 2010/12 107-112
  • X線・放射光の分光
    長岡伸一 (Contributor, 6章、原子・分子のX線分光)
    講談社サイエンティフィク 2009/04 9784061571020 178 109-137
  • ビタミンE研究の進歩XIII
    向井和男, 徳永愛子, 伊藤慎吾, 大内綾, 兼崎友, 小原敬士, 長岡伸一, 阿部皓一 (Contributor, ビタミンE同族体のミセル中におけるラジカル消去反応速度と生物活性の相関)
    ビタミンE研究会 2009/03 101 35-41
  • Atom Tunneling Phenomena in Physics, Chemistry and Biology
    S. Nagaoka (Contributor, Atom Tunneling Reaction of Vitamin E in Antioxidant, Prooxidant and Regeneration Reactions)
    Springer 2004 3540015264 313 285-303
  • ビタミンE研究の進歩Ⅹ(1)
    小原敬士, 西奥義憲, 長岡伸一, 向井和男 (Contributor, 時間分解ESR法によるビタミンKビタミンE連結分子の光誘起分子内抗酸化反応の研究)
    ビタミンE研究会 2002/01 72-77
  • ビタミンE研究の進歩X(2)
    三谷修二, 小原敬士, 長岡伸一, 向井和男 (Contributor, 茶カテキンとその関連化合物によるビタミンE再生反応の速度論的研究)
    ビタミンE研究会 2002/01
  • ビタミンE研究の進歩Ⅸ(1)
    小原敬士, 恵谷優子, 長岡伸一, 向井和男 (Contributor, 時間分解ESR法によるビタミンE類の一重項酸素消光速度の測定)
    ビタミンE研究会 2000/12 1-6
  • ビタミンE研究の進歩Ⅸ(2)
    西奥義憲, 長岡伸一, 向井和男 (Contributor, ビタミンCによるビタミンE再生反応におけるトンネル効果の研究)
    ビタミンE研究会 2000/12 43-47
  • Phytochemicals and Phytopharmacenticals
    K. Mukai, Y. Kanesaki, Y. Egawa, S. Nagaoka (Contributor, Chapter 20, Free Radical-Scavenging Action of Catechin and Related Compounds in Homogeneous and Micellar Solutions)
    AOCS Press 2000 222-238
  • Food Factors for Cancer Prevention
    K. Mukai, W. Oka, K. Watanabe, Y. Egawa, S. Nagaoka, J. Terao (Contributor, Kinetic Study of Free Radical-Scavenging Action of Flavonoids in Homogeneous and Aqueous Triton X-100 Micellar Solutions)
    Springer-Verlag 1997/07 9784431701965 627-631
  • ビタミンE研究の進歩Ⅶ
    向井和男, 尾方まゆみ, 松本英之, 江川義史, 長岡伸一 (Contributor, コーヒー酸誘導体のフリーラジカル消去活性とそのメカニズム)
    共立出版 1997/02 20-25
  • Proceedings of the International Symposium on Natural Antioxidants: Molecular Mechanisms and Health Effects
    K. Mukai, W. Oka, Y. Egawa, S. Nagaoka, J. Terao (Contributor, Chapter 56, A Kinetic Study of the Free-Radical-Scavenging Action of Flavonoids in Aqueous Triton X-100 Micellar Solution)
    AOCS Press 1996/05 9780935315691 557-568
  • ビタミンE研究の進歩Ⅵ
    岡渉, 江川義史, 長岡伸一, 向井和男, 寺尾純二 (Contributor, フラボノイドのビタミンE再生反応速度のpH依存性)
    共立出版 1996/01 6-11
  • ビタミンE研究の進歩Ⅴ
    長岡伸一, 井上雅代, 宮崎智光, 向井和男, 長嶋雲兵 (Contributor, ビタミンEの抗酸化反応のポテンシャル曲面の研究)
    共立出版 1995/03 56-62
  • Particles and Fields Series 49, Synchrotron Radiation and Dynamic Phenomena
    M. Ukai, K. Kameta, K. Shinsaka, Y. Hatano, T. Hirayama, S. Nagaoka, K. Kimura (Contributor, State Selective Ionization of O2 in a Framework of van der Waals Molecules)
    American Institute of Physics 1992/09 179-189

Conference Activities & Talks

  • 向井和男, 大内綾, 永井かなえ, 北垣沙耶, 丸岡靖大, 中村悠, 長岡伸一
    第31回ビタミンE研究会  2020/01  愛媛大学(愛媛県松山市)  ビタミンE研究会
     
    O-20 1月10日(金)-11日(土)
  • 野本七帆, 井上和優, 小原敬士, 長岡伸一
    第31回ビタミンE研究会  2020/01  愛媛大学(愛媛県松山市)  ビタミンE研究会
     
    P-9 1月10日(金)-11日(土)
  • 中村悠, 谷口裕樹, 長岡伸一, 向井和男
    第31回ビタミンE研究会  2020/01  愛媛大学(愛媛県松山市)  ビタミンE研究会
     
    P-8 1月10日(金)-11日(土)
  • 丸岡靖大, 北垣沙耶, 長岡伸一, 向井和男
    第31回ビタミンE研究会  2020/01  愛媛大学(愛媛県松山市)  ビタミンE研究会
     
    P-7 1月10日(金)-11日(土)
  • ビタミンEの抗酸化反応  [Invited]
    長岡 伸一
    愛媛県立松山西中等教育学校  2019/07  松山  愛媛県立松山西中等教育学校
  • 長岡 伸一
    第30回ビタミンE研究会  2019/01  東北大学片平キャンパス  ビタミンE研究会
     
    次年度愛媛大学で開催される第31回ビタミンE研究会の概要について口頭で2回、ポスターで1回紹介し、参加をお願いした。
  • 長岡伸一, 小久保達伸, 寺前裕之, 長嶋雲兵
    2018年日本化学会中国四国支部大会  2018/11  愛媛県松山市  日本化学会中国四国支部
     
    1H-03 ヒュッケル分子軌道法の直感的理解のための新しい実習について報告する。実習のためにエクセルマクロを用いてベンゼンのような対称分子にも適用できる行列対角化の方法を開発した。実習では他の二つのエクセルマクロを用いてヒュッケル分子軌道の等高線図を描画する。これらのマクロを用いたヒュッケル法の実習は、理論の概念を明確に示すという点で学部学生の量子化学の教育に有用である。
  • Si-(sub)oxides Selective Local Valence Electronic States of HfSi2/Si-(sub)oxides/Si(110) and HfO2/Si-(sub)oxides/Si(110)  [Not invited]
    T. Kakiuchi, K. Ikeda, K. Mase, S. Nagaoka
    The International Conference on Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces (MPS-2018)  2018/08  Danubius Hotel Flamenco, Budapest, Hungary
  • Development of Antioxidative Absorption Capacity Assay Method for Foods  [Invited]
    Shin-ichi Nagaoka
    Seminar in Josai University  2018/07  Sakado, Japan  Josai University
     
    76名参加
  • 長岡伸一, 寺前裕之, 小久保達信, 長嶋雲兵
    日本コンピュータ化学会2018春季年会  2018/06  東京工業大学大学院社会理工学研究科棟 大岡山西9号館2階  日本コンピュータ化学会
     
    1P09 ベンゼンなどの高い対称性を持っ分子のヒュッケル解のπ軌道のような対称性の高い分子軌道を特別な労力なく求めるのは難しい。我々は、対称性の高い固有ベクトルを計算の効率を落とさないで求める行列対角化法を開発したので、報告する。
  • D. Koyama, M. Yamazaki, T. Kakiuchi, S. Nagaoka, K. Mase
    The 98th CSJ Annual Meeting  2018/03  Funabashi Campus, College of Science and Technology, Nihon University, Funabashi, Japan  Chemical Society of Japan
     
    1PB-024 Both of Hafnium and Si(110) substrate are attracting high interests as the next generation materials for MOS-FET. In this study, we fabricated an ultrathin hafnium Silicide (HfSi2) film on a clean Si(110)-16×2 single domain surface [HfSi2/Si(110)]. And surface- and interface-selective local valence electronic states were investigated with Si-L23VV Auger-electron - Si-2p photoelectron coincidence spectroscopy. As a result, the local valence electronic state of Si on surface was distributed on lower binding energy side than the one at interface. Furthermore, we prepared some ultrathin HfSi2/Si(110) films with different thicknesses in order to reveal the thickness dependency in local valence electronic states on surface and at interface.
  • 長嶋雲兵, 田島澄恵, 中山尚史, 寺前裕之, 長岡伸一
    日本コンピュータ化学会2017秋季年会  2017/10  くまもと県民交流館パレア  日本コンピュータ化学会
     
    2P01
  • Shin-ichi Nagaoka
    Topical Meeting of the Vacuum Society of Japan, 2017-3  2017/09  Ehime University  Vacuum Society of Japan
  • Kazuo Mukai, Yuki Bandoh, Shin-ichi Nagaoka, Hayato Itoh, Eri Kobayashi, Kiyotaka Nakagawa
    The Asian Conference Oleo Science 2017 & the 56th Annual Meeting of the Japan Oil Chemists' Society  2017/09  Tolyo University of Science  Japan Oil Chemists' Society
     
    3E14
  • Kazuo Mukai, Aya Ouchi, Nagao Azuma, Shingo Takahashi, Koichi Aizawa, Shin-ichi Nagaoka
    The 55th Annual Meeting of the Society of Electron Spin Science and Technology (SEST2016)  2016/11  Osaka City University  Society of Electron Spin Science and Technology
     
    1B5 11月10~12日
  • Yuki Bandoh, Koji Kawada, Kazuo Mukai, Yasuhiro Sakurai, Gen Hattori, Aya Kuranaka, Shin-ichi Nagaoka
    The 55th Annual Meeting of the Society of Electron Spin Science and Technology (SEST2016)  2016/11  Osaka City University  Society of Electron Spin Science and Technology
     
    2P38 11月10~12日
  • T. Kakiuchi, K. Ikeda, S. Nagaoka, K. Mase
    Joint Symposium of the Surface Sience Society of Japan and the Vacuum Society of Japan, SSVS2016  2016/11  Nagoya Congress Center  Surface Science Society of Japan
     
    3Kp08Y 11 月 29 日(火)- 12 月 1 日(木)
  • 小原敬士, 古信裕, 尾下愛美, 長岡伸一
    2016年日本化学会中国四国支部大会香川大会  2016/11  香川大学幸町キャンパス  日本化学会中国四国支部
     
    1P16 11月5日(土)、6日(日)
  • 平野恒夫, 長嶋雲兵, 寺前裕之, 長岡伸一
    日本コンピュータ化学会2016秋季年会  2016/10  島根大学 松江キャンパス  日本コンピュータ化学会
     
    1P-03 10月22日(土) 〜 23日(日)
  • Takuhiro Kakiuchi, Kyohei Ikeda, Shin-ichi Nagaoka, Kazuhiko Mase
    The 10th Annual Meeting of Japan Society for Molecular Science  2016/09  KOBE FASHION MART  Japan Society for Molecular Science
     
    3P064 9月13日(火)~15日(木)
  • Yuki Bandoh, Keishi Ohara, Shin-ichi Nagaoka
    26th IUPAC International Symposium on Photochemistry  2016/04  Osaka City Central Public Hall  IUPAC
     
    2P36 April 3-8
  • 垣内拓大, 池田恭平, 長岡伸一, 間瀬一彦
    2015年度量子ビームサイエンスフェスタ  2016/03  エポカルつくば  PF
     
    079G,080G 3月15日(火)~16日(水)
  • ビタミンEの一重項酸素消去速度に及ぼす金属塩の効果  [Not invited]
    長岡伸一, 高橋京香, 中村明日香, 小原敬士, 向井和男
    第27回ビタミンE研究会  2016/01  アルファあなぶきホール(香川県高松市)  ビタミンE研究会
     
    1月8日(金)~9日(土)
  • Hydrogen adsorption on clean Si(110)-16×2 single domain surface studied by X-ray photoelectron and Auger-electron coincidence spectroscopies  [Not invited]
    垣内拓大, 中納佑二, 長岡伸一, 間瀬一彦
    第35回表面科学会学術講演会  2015/12  Tsukuba  Surface Science Society of Japan
     
    1P30 12月1日(火)-12月3日(木)
  • Hafnium adsorption on clean Si(110)-16×2 single domain surface studied by low energy electron diffraction and electron spectroscopy  [Not invited]
    垣内拓大, 桂木拓磨, 中納佑二, 長岡伸一, 間瀬一彦
    第35回表面科学会学術講演会  2015/12  Tsukuba  Surface Science Society of Japan
     
    1P31 12月1日(火)-12月3日(木)
  • 近赤外発光スポット検出によるゲル中の一重項酸素寿命計測  [Not invited]
    小原敬士, 北平有望, 長岡伸一
    2015年日本化学会中国四国支部大会  2015/11  岡山大学津島キャンパス  日本化学会中国四国支部
     
    14SC10 11月14日(土),15日(日)
  • TD DFT法によるOHBAの吸光・発光スペクトルの理論的研究  [Not invited]
    新井健文, 長岡伸一, 長嶋雲兵, 寺前裕之
    日本コンピュータ化学会2015年秋季年会  2015/10  函館市地域交流まちづくりセンター  日本コンピュータ化学会
     
    2P04 10月30日(金)~31日(土)
  • Hafnium adsorption on clean Si(110)-16×2 single domain surface studied with photoelectron spectroscopy  [Not invited]
    Takuhiro Kakiuchi, Takuma Katsuragi, Yuji Nakano, Shin-ichi Nagaoka, Kauzhiko Mase
    13th International Conference on Electron Spectroscopy and Structure (ICESS-15)  2015/09  Stonybrook University, New York 
    9/28-10/2
  • Hydrogen adsorption to clean Si(110)-16×2 single domain surface and its chemical states  [Not invited]
    Takuhiro Kakiuchi, Yuji Nakano, Shin-ichi Nagaoka, Kauzhiko Mase
    13th International Conference on Electron Spectroscopy and Structure (ICESS-15)  2015/09  Stonybrook University, New York 
    9/28-10/2
  • SiCl4分子のSi K殻オージェ電子放出に続くSi L殻カスケードオージェ電子放出  [Not invited]
    坂東宥奎, 望月系, 長岡伸一, 福澤宏宣, 高梨司, 立花徹也, 山田周平, 上田潔, 為則雄祐, 鈴木功
    第9回分子科学討論会2015東京  2015/09  東京工業大学大岡山キャンパス  分子科学会
     
    3P015 9月16日(水)~19日(土)
  • Nodal-Plane Model in Photochemistry  [Invited]
    Shin-ichi Nagaoka, Keishi Ohara
    27th International Conference on Photochemistry  2015/06  International Convention Center JEJU (ICC JEJU), Jeju Island, Korea 
    June 28~July 3
  • TD DFT法による分子内プロトン移動反応の理論的研究(3)  [Not invited]
    新井健文, 長岡伸一, 長嶋雲兵, 寺前裕之
    日本コンピュータ化学会2015春季年会  2015/05  東京工業大学大学院社会理工学研究科  日本コンピュータ化学会
     
    1P13 5月28日(木)~29日(金)
  • Surface Structure and Local Valence Electronic States of Si(110)-16×2 Surface after Exposure to Water: XPS and Auger-Photoelectron Coincidence Study  [Not invited]
    T. Kakiuchi, S. Nishiura, J. Kawamoto, S. Nagaoka, K. Mase
    Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014)  2014/12  Hapuna Beach Prince Hotel Big Island of Hawaii 
    NM-TuP17 December 7 - 11
  • Dissociative adsorption of H2O on clean Si(110)-16×2 surface: change of surface property and one-dimensional structure  [Not invited]
    垣内拓大, 西浦伸吾, 川本淳滋, 長岡伸一, 間瀬一彦
    第34回表面科学学術講演会  2014/11  Matsue  Surface Science Society of Japan
     
    7Cp09
  • H3+、H3、H3-の結合様式と構造  [Not invited]
    Amih Sagan, 田島澄恵, 中山尚史, 長嶋雲兵, 寺前裕之, 長岡伸一
    第37回情報化学討論会  2014/11  豊橋商工会議所 
    P07 11月27日(木)・28日(金)
  • TD DFT法による分子内プロトン移動反応の理論的研究(2)  [Not invited]
    新井健文, 寺前裕之, 長岡伸一, 長嶋雲兵
    日本コンピュータ化学会2014年秋季年会  2014/10  日本大学工学部(福島県郡山市)  日本コンピュータ化学会
     
    1P06 10月18日(土) ~ 19日(日)
  • H3+、H3、H3-の結合様式と構造  [Not invited]
    田島澄恵, 中山尚史, 長嶋雲兵, 寺前裕之, 長岡伸一
    日本コンピュータ化学会2014年秋季年会  2014/10  日本大学工学部(福島県郡山市)  日本コンピュータ化学会
     
    2P15 10月18日(土) ~ 19日(日)
  • 分子軌道計算におけるN2-およびO2-の基底状態のdiffuse関数依存性  [Not invited]
    寺前裕之, 長岡伸一, 長嶋雲兵
    第8回分子科学討論会 2014 東広島  2014/09  広島大学東広島キャンパス  分子科学会
     
    3P119 9月21日(日)~24日(水)
  • Dissociative adsorption of H2O on clean Si(110)-16×2 surface: change of surface property and one-dimensional structure  [Not invited]
    垣内拓大, 西浦伸吾, 川本淳滋, 長岡伸一, 間瀬一彦
    第8回分子科学討論会 2014 東広島  2014/09  Hiroshima University  Japan Society for Molecular Science
     
    3P076 9月21日(日)~24日(水)
  • シクロデキストリンで水溶化した香辛料成分カプサイシンの一重項酸素消去活性  [Not invited]
    小原敬士, 平岡奈保子, 長岡伸一
    第67回日本酸化ストレス学会学術集会  2014/09  同志社大学(京都市上京区)  日本酸化ストレス学会
     
    P53 9/4-5
  • Correlation between Excited-State Intramolecular Proton-Transfer and Singlet-Oxygen Quenching Activity in Intramolecularly Hydrogen-Bonded Anthraquinone Derivatives  [Invited]
    Shin-ichi Nagaoka, Hikaru Endo, Keishi Ohara
    248th American Chemical Society National Meeting & Exposition  2014/08  San Francisco, USA  American Chemical Society
     
    PHYS305 August 10-14
  • 食品が一重項酸素を消滅させる能力を評価する方法の開発  [Invited]
    長岡伸一
    平成26年度愛媛大学研究員交流サロン  2014/08  愛媛大学南加記念ホール  愛媛大学
     
    8月26日(火)
  • Photofragmentation of the K-shell excited cis-1,1,2,2,3,4-hexafluorocyclobutane probed by partial ion yield and multiple-ion coincidence methods  [Not invited]
    K. Okada, T. Nakashima, Y. Kajitani, I. H. Suzuki, S. Nagaoka, Y. Tamenori
    International Workshop on Photoionization and Resonant Inelastic X-Ray Scattering  2014/08  Erice, Sicily, Italy 
    August 26~September 1
  • カテコールアミンのラジカル消去活性−α-トコフェロールとの相乗効果−  [Not invited]
    長岡伸一, 永井かなえ, 大内綾, 向井和男
    日本ビタミン学会第66回大会  2014/06  姫路商工会議所  日本ビタミン学会
     
    2-I-14 6月13日(金)~14日(土)
  • ビタミンEの一重項酸素消去速度に及ぼす金属塩の効果  [Not invited]
    中村明日香, 大内綾, 長岡伸一, 東長雄, 向井和男
    日本ビタミン学会第66回大会  2014/06  姫路商工会議所  日本ビタミン学会
     
    2-I-13 6月13日(金)~14日(土)
  • リポソーム膜中におけるトコトリエノール類のラジカル補足反応速度の測定  [Not invited]
    福澤健治, 柴田螢, 大内綾, 長岡伸一, 向井和男
    日本ビタミン学会第66回大会  2014/06  姫路商工会議所  日本ビタミン学会
     
    2-I-12 6月13日(金)~14日(土)
  • TD DFT法による分子内プロトン移動反応の理論的研究  [Not invited]
    新井健文, 寺前裕之, 長岡伸一, 長嶋雲兵
    日本コンピューター化学会2014年春季年会  2014/05  東京工業大学大岡山キャンパス  日本コンピュータ化学会
     
    2P01 5月29日(木) ~ 30日(金)
  • N2-およびO2-の基底状態のdiffuse関数依存性  [Not invited]
    杉山達人, 長岡伸一, 長嶋雲兵, 寺前裕之
    第17回理論化学討論会  2014/05  名古屋大学東山キャンパス  理論化学研究会
     
    1P25 5月22日(木)~24日(土)
  • 気相分子のSi KLL共鳴オージェ電子スペクトルにおける励起軌道、サイトへの依存性  [Not invited]
    鈴木功, 長岡伸一, 為則雄祐, 高橋修, 上田潔, 福沢宏宣
    軟X線光化学研究会  2014/01  旬彩(光都プラザ)  SPring-8
     
    2月1日(土)
  • Atomic Structure of Si(110)-16×2 Studied by Auger Photoelectron Coincidence Spectroscopy  [Not invited]
    T. Kakiuchi, Y. Yoshizaki, H. Kubota, Y. Sato, K. Mase, S. Nagaoka
    9th international symposium on atomic level characterizations for new materials and devices '13 (ALC'13)  2013/12  Sheraton Kona, The Big Island, Hawaii, 
    05P02 December 2 (Mon)~6 (Fri)
  • トコトリエノール同族体とパーム油抽出物の一重項酸素消去活性(SOAC値)評価のミセル溶液系への展開  [Not invited]
    向井和男, 石川絵理, 大内綾, 長岡伸一, 鈴木智美, 泉澤勝弘, 小池泰介
    第10回日本トコトリエノール研究会  2013/11  産業技術総合研究所臨海副都心センター(東京都江東区) 
    11月25日(月)
  • Correlation between Excited-State Intramolecular Proton-Transfer and Singlet-Oxygen Quenching Activity in Intramolecularly Hydrogen-Bonded Anthraquinone Derivatives  [Not invited]
    長岡伸一, 遠藤光, 小原敬士
    2013年光化学討論会  2013/09  Ehime University  Japanese Photochemistry Association
     
    3P020 9月11日(水)~ 13日(金)
  • Resonant-Auger-Induced Interatomic Coulombic Decay in Ar2, ArKr and ArXe  [Not invited]
    M. Kimura, H. Fukuzawa, T. Tachibana, Y. Ito, K. Sakai, S. Mondal, M. Okunishi, E. Kukk, M. Schöffler, J. Williams, Y. Jiang, Y. Kohno, S. Nagaoka, Y. Tamenori, N. Saito, K. Ueda
    38th International Conference on Vacuum Ultraviolet and X-ray Physics (VUVX2013)  2013/07  Hefei, Anhui Province, China 
    S4 12-19 July
  • Resonant-Auger-induced Interatomic Coulombic decay in Ar2, ArKr and ArXe  [Not invited]
    M. Kimura, H. Fukuzawa, T. Tachibana, Y. Ito, K. Sakai, S. Mondal, M. Okunishi, E. Kukk, M. Schöffler, J. Williams, Y. Jiang, Y. Kohno, S. Nagaoka, Y. Tamenori, N. Saito, K. Ueda
    第29回化学反応討論会  2013/06  Tohoku University 
    1P43 6月5日(水) - 6月7日(金)
  • トコフェロールとユビキノール(ビタミンC)の共存による抗酸化反応速度の増加と酸化促進効果の抑制  [Not invited]
    向井和男, 大内綾, 中矢沙織, 長岡伸一
    第66回日本酸化ストレス学会学術集会  2013/06  名古屋市ウインクあいち(中村区)  日本酸化ストレス学会
     
    O-26 6月13-14日
  • 食品などにおける抗酸化剤によるフリーラジカル消去活性の測定法の開発 ( ARAC 法 )  [Not invited]
    長岡伸一, 永井かなえ, 藤井裕子, 大内綾, 向井和男
    日本ビタミン学会第65回大会  2013/05  一橋大学一橋講堂(旧、学術総合センター)  日本ビタミン学会
     
    2-Ⅳ-20 5月17日(金)~18日(土)
  • 還元型ピロロキノリンキノン (PQQH2) の抗酸化活性の評価  [Not invited]
    向井和男, 大内綾, 長岡伸一, 池本一人, 中野昌彦
    日本ビタミン学会第65回大会  2013/05  一橋大学一橋講堂(旧、学術総合センター  日本ビタミン学会
     
    2-Ⅱ-15 5月17日(金)~18日(土)
  • トコフェロールとユビキノール(ビタミンC)の抗酸化反応における相乗効果の研究:共存による反応速度の増加と酸化促進効果の抑制  [Not invited]
    大内綾, 中矢沙織, 長岡伸一, 向井和男
    日本ビタミン学会第65回大会  2013/05  一橋大学一橋講堂(旧、学術総合センター)  日本ビタミン学会
     
    2-Ⅳ-21 5月17日(金)~18日(土)
  • Multi-emitting properties of iridium complexes monolayer by layer-by-layer deposition  [Not invited]
    佐藤久子, 森本和也, 小原敬士, 長岡伸一, 田村堅志
    日本化学会第93春季年会(2013)  2013/03  Ritsumeikan University  Chemical Society of Japan
     
    3PC-050 3月22日(金)~25日(月)
  • トコトリエノール同族体とパーム油抽出物のフリーラジカル消去活性  [Not invited]
    向井和男, 大内綾, 長岡伸一, 鈴木智美, 泉澤勝弘
    第9回日本トコトリエノール研究会  2012/11  産業技術総合研究所臨海副都心センター別館(東京都江東区) 
    演題1 11月 12 日( 月)
  • トコトリエノール同族体とパーム油抽出物の一重項酸素消去活性 (SOAC値) の評価  [Not invited]
    石川絵理, 大内綾, 長岡伸一, 向井和男, 泉澤勝弘, 小池泰介
    第9回日本トコトリエノール研究会  2012/11  産業技術総合研究所臨海副都心センター別館(東京都江東区) 
    演題2 11月 12 日( 月)
  • Synthesis of naphthoisoindole by pericyclic reaction and its properties  [Not invited]
    清家彩, 長岡伸一, 中江隆博, 森重樹, 奥島鉄雄, 宇野英満
    第42回複素環化学討論会  2012/10  Kyoto 
    2P124 10月11日(木)~10月13日(土)
  • 分子軌道法によるHF, LiH, HeH+の双極子モーメント  [Not invited]
    寺前裕之, 長岡伸一, 長嶋雲兵
    日本コンピュータ化学会2012秋季年会  2012/10  山形大学小白川キャンパス(山形市)  日本コンピュータ化学会
     
    1P02 10月13日(土),14日(日)
  • A variety of Resonant characteristic behavior of Si KLL Auger decays of SiCl4  [Not invited]
    鈴木功, 河野優太郎, 坂井健太郎, 木村美紅, 上田潔, 為則雄祐, 高橋修, 長岡伸一
    第6回分子科学討論会  2012/09  Tokyo University  Japan Society for Molecular Science
     
    2P007 9月18日(火)~21日(金)
  • Interatomic Coulombic decay in Ar dimer after Ar 2p→3d resonant Auger decay  [Not invited]
    木村美紅, 福澤宏宣, 坂井健太郎, 奥西みさき, Mondal Subhendu, Kukk Edwin, 河野優太郎, 長岡伸一, 為則雄祐, 斎藤則生, 上田潔
    第6回分子科学討論会  2012/09  Tokyo University  Japan Society for Molecular Science
     
    3P001 9月18日(火)~21日(金)
  • Photofragmentation of Perfluorocyclobutane at the C and F K-Edges  [Not invited]
    K. Okada, T. Teranishi, A. Suemitsu, I. H. Suzuki, S. Nagaoka, K. Tabayashi, Y. Tamenori
    12th International Conference of Electron Spectroscopy and Structure (ICESS2012)  2012/09  Palais des Congres Saint-Malo France 
    PR-2-PO-OKA-01 September 16-21
  • オージェ電子-光電子コインシデンス分光法によるSi(110)-16×2清浄表面の局所価電子状態の観測  [Not invited]
    垣内拓大, 佐藤勇輝, 花岡咲, 長岡伸一, 間瀬一彦
    第6回分子科学討論会2012  2012/09  東京大学本郷キャンパス  分子科学会
     
    9.18 - 9.21
  • Mechanism of Highly Charged Ar Ions Production Induced by Inner-Shell Ionization Studied Using Auger-Electron - Ion Coincidence Spectroscopy  [Not invited]
    T. Kakicuhi, S. Hanaoka, D. Tamaki, S. Fujiwara, Y. Yoshizaki, K. Mase, S. Nagaoka
    International Conference on Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces (MPS2012)  2012/08  Lakeside Convention Center Tegeler Seeterrassen, Berlin, Germany 
    August 27 - September 1
  • Local Valence Electronic States of Silicon Nitride Ultrathin Films on Si(111) Studied by Using Auger Photoelectron Coincidence Spectroscopy (APECS)  [Not invited]
    T. Kakiuchi, M. Tahara, S. Nagaoka, K. Mase
    International Conference on Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces (MPS2012)  2012/08  Lakeside Convention Center Tegeler Seeterrassen, Berlin, Germany 
    August 27 - September 1
  • 食品の一重項酸素消去活性評価法(SOAC法)の確立  [Invited]
    相澤宏一, 高橋慎吾, 岩崎裕子, 稲熊隆博, 大内綾, 長岡伸一, 寺尾純二, 向井和男
    第65回日本酸化ストレス学会学術集会  2012/06  徳島県郷土文化会館  日本酸化ストレス学会
     
    S1-4 6月7日(木)~8日(金)
  • 食品への応用を目指したフェノール系抗酸化剤の一重項酸素消去活性評価法の確立 (第2報)  [Not invited]
    向井和男, 大内綾, 長岡伸一, 高橋慎吾, 相澤宏一, 稲熊隆博, 寺尾純二
    日本ビタミン学会第64回大会  2012/06  長良川国際会議場  日本ビタミン学会
     
    1-Ⅱ-5 6月22日(金)~23日(土)
  • ビタミンEラジカルと金属イオン間の錯形成の効果  [Not invited]
    河野優太郎, 大内綾, 長岡伸一, 向井和男
    日本ビタミン学会第64回大会  2012/06  長良川国際会議場  日本ビタミン学会
     
    1-Ⅱ-3 6月22日(金)~23日(土)
  • トコフェロールとトコトリエノールの抗酸化反応における相乗効果の研究  [Not invited]
    大内綾, 長岡伸一, 向井和男, 鈴木智美, 泉澤勝弘
    日本ビタミン学会第64回大会  2012/06  長良川国際会議場  日本ビタミン学会
     
    1-Ⅱ-4 6月22日(金)~23日(土)
  • Stopped-Flow分光光度計を用いたα-, β-, γ-, δ-トコフェロシキルラジカルと金属陽イオンの錯形成の研究  [Not invited]
    向井和男, 河野優太郎, 大内綾, 長岡伸一
    第65回日本酸化ストレス学会学術集会  2012/06  徳島県郷土文化会館  日本酸化ストレス学会
     
    O-46 6月7日(木)~8日(金)
  • Study of Highly Charged Ar Ions Formed by Electron-Impact Ionization  [Not invited]
    垣内拓大, 花岡咲, 間瀬一彦, 長岡伸一
    第28回化学反応討論会  2012/06  Kyushu University 
    1P18 6月6日(水) - 6月8日(金)
  • マイクロプレートリーダーを用いた一重項酸素消去活性測定法(SOAC法)の検討  [Not invited]
    高橋慎吾, 岩崎裕子, 相澤宏一, 稲熊隆博, 大内綾, 向井和男, 長岡伸一, 寺尾純二
    第65回日本酸化ストレス学会学術集会  2012/06  徳島県郷土文化会館  日本酸化ストレス学会
     
    P54 6月7日(木)~8日(金)
  • 野菜および果実の一重項酸素消去活性測定法(SOAC法)を用いた評価  [Not invited]
    岩崎裕子, 高橋慎吾, 相澤宏一, 稲熊隆博, 大内綾, 向井和男, 長岡伸一, 寺尾純二
    第65回日本酸化ストレス学会学術集会  2012/06  徳島県郷土文化会館  日本酸化ストレス学会
     
    P53 6月7日(木)~8日(金)
  • Free Radical Scavenging Activity of Vitamin E Emulsion  [Not invited]
    小原敬士, 迫佳志, 長岡伸一
    日本化学会第92春季年会  2012/03  Keio University  Chemical Society of Japan
     
    3PB-047 3月25日(日)~28日(水)
  • Multi-emitting phenomena by the hybrid fims of Iridium(III) complex and clays  [Not invited]
    中谷康彦, 森本和也, 小原敬士, 長岡伸一, 田村堅志, 佐藤久子
    日本化学会第92春季年会  2012/03  Keio University  Chemical Society of Japan
     
    3F8-11 3月25日(日)~28日(水)
  • Local Valence Electronic States of Si(110)-16×2 Clean Surface Studied Using Auger-Photoelectron Coincidence Spectroscopy  [Not invited]
    垣内拓大, 佐藤勇輝, 花岡咲, 坂尾諒, 新江定憲, 田中正俊, 長岡伸一, 間瀬一彦
    10-01 PFシンポジウム  2012/03  Tsukuba  PF
     
    3月15-16日
  • Construction and Evaluation of Auger-Photoelectron Coincidence Apparatus at BL13 of HiSOR  [Not invited]
    T. Kakiuchi, Y. Sato, S. Hanaoka, S. Kajikawa, H. Hayashita, M. Ogawa, S. Arae, S. Wada, T. Sekitani, S. Nagaoka, M. Tanaka, K. Mase
    第16回広島放射光国際シンポジウム  2012/03  Higashi-Hiroshima  HiSOR
     
    3月1日(木)-2日(金)
  • 卵黄レシチンリポソーム膜におけるビタミンEのラジカル消去反応速度  [Not invited]
    福澤健治, 柴田瑩, 大内綾, 長岡伸一, 向井和男
    第23回ビタミンE研究会  2012/01  ホテルJALシティ田町(東京都港区)  ビタミンE研究会
     
    O-20 1月27-28日
  • ビタミンC や還元型CoQ10 によるビタミンE 再生反応におけるトンネル効果  [Invited]
    長岡伸一
    日本放射線影響学会第54回大会  2011/11  神戸商工会議所会館  日本放射線影響学会
     
    W1-4 11月17日~19日
  • Qnantum Effect in Antioxidant Reaction of Vitamin E  [Invited]
    長岡伸一
    2011年日本化学会西日本大会  2011/11  Tokushima University  Chemical Society of Japan
     
    1B-09 11月12日(土)-13日(日)
  • High-efficiency of salt of caffeic acid in singlet oxygen quenching  [Not invited]
    小原敬士, 新崎由佳, 長岡伸一
    2011年日本化学会西日本大会  2011/11  Tokushima University  Chemical Society of Japan
     
    2P-14 11月12日(土)-13日(日)
  • 何故水分子の構造は曲がっていて水酸化アルカリ金属分子は直線なのか?  [Not invited]
    Amih Sagan, 長嶋雲兵, 青山智夫, 長岡伸一
    日本コンピュータ化学会2011秋季年会  2011/11  福井商工会議所(福井市)  日本コンピュータ化学会
     
    2P13 11月4日(金)~ 5日(土)
  • Si(110)-16×2清浄表面の最安定構造モデル  [Not invited]
    垣内拓大, 久保田裕之, 田原雅士, 間瀬一彦, 長岡伸一
    第5回分子科学討論会2011札幌  2011/09  札幌コンベンションセンター  分子科学会
     
    1P052 9月20日(火)~23日(金)
  • 異核2原子分子水素化リチウムLiHの分子軌道エネルギー準位図  [Not invited]
    長嶋雲兵, 寺前裕之, 長岡伸一
    第5回分子科学討論会2011札幌  2011/09  札幌コンベンションセンター  分子科学会
     
    1P127 9月20日(火)~23日(金)
  • TD DFT法による分子内プロトン移動反応の研究(2)  [Not invited]
    寺前裕之, 長岡伸一, 長嶋雲兵
    第5回分子科学討論会2011札幌  2011/09  札幌コンベンションセンター  分子科学会
     
    4P091 9月20日(火)~23日(金)
  • モンモリロナイトと発光性イリジウム錯体とのハイブリッドLB膜の発光挙動  [Not invited]
    中谷康彦, 堤響子, 中江隆博, 小原敬士, 長岡伸一, 森本和也, 田村堅志, 佐藤久子
    第55回粘土科学討論会  2011/09  鹿児島大学(鹿児島市) 
    P62 9月14日(水)~16日(金)
  • モンモリロナイトと発光性イリジウム錯体とのハイブリッドLB膜による酸素センシング  [Not invited]
    中谷康彦, 堤響子, 中江隆博, 小原敬士, 長岡伸一, 森本和也, 田村堅志, 佐藤久子
    日本化学会新領域研究グループ「低次元無機有機複合系の光化学」のサマーセミナー  2011/09  鹿児島大学(鹿児島市)  日本化学会新領域研究グループ「低次元無機有機複合系の光化学」
  • 内殻励起cis-ヘキサフルオロシクロブタンの光解離ダイナミクス  [Not invited]
    中島徹, 梶谷祐美子, 岡田和正, 末光篤, 為則雄祐, 鈴木功, 長岡伸一
    第5回分子科学討論会2011札幌  2011/09  札幌コンベンションセンター  分子科学会
     
    1P005 9月20日(火)~23日(金)
  • Photofragmentation of the K-shell excited perfluorocyclobutane probed by a multiple-ion coincidence technique  [Not invited]
    K. Okada, T. Terashima, A. Suemitsu, I. H. Suzuki, S. Nagaoka, K. Tabayashi, Y. Tamenori
    XXVII International Conference on Photonic, Electronic and Atomic Collisions (ICPEAC2011)  2011/07  Belfast, Northern Ireland, UK Queen's University Belfast 
    Th148 27 July - 2 August
  • Development of singlet oxygen absorption capacity (SOAC) assay method and the quenching activity of singlet oxygen by carotenoids and vegetables  [Not invited]
    Shingo Takahashi, Yuko Iwasaki, Aya Ouchi, Koichi Aizawa, Takahiro Inakuma, Shin-ichi Nagaoka, Junji Terao, Kazuo Mukai
    16th International Symposium on Carotenoids  2011/07  Kraków (an old capital and strong academic center of Poland) 
    Session 5.2 17th to the 22nd of July
  • 食品への応用を目指したカロテノイドの一重項酸素消去活性評価法の確立  [Not invited]
    向井和男, 大内綾, 長岡伸一, 相澤宏一, 岩崎裕子, 稲熊隆博, 寺尾純二
    日本ビタミン学会第63回大会  2011/06  安田女子大学(広島市安佐南区)  日本ビタミン学会
     
    2-Ⅲ-21 6月4日(土)~5日(日)
  • ユビキノ―ルによるビタミンEの再生反応に及ぼす金属塩の効果とメカニズム  [Not invited]
    大井正則, 大内綾, 長岡伸一, 向井和男
    日本ビタミン学会第63回大会  2011/06  安田女子大学(広島市安佐南区)  日本ビタミン学会
     
    2-Ⅰ-15 6月4日(土)~5日(日)
  • ユビキノールによるビタミンEラジカル再生反応におけるトンネル効果  [Not invited]
    大内綾, 長岡伸一, 向井和男
    日本ビタミン学会第63回大会  2011/06  安田女子大学(広島市安佐南区)  日本ビタミン学会
     
    2-Ⅰ-13 6月4日(土)~5日(日)
  • ビタミンEラジカルと生体金属イオン間の錯形成とラジカルの二分子反応に及ぼす効果  [Not invited]
    河野優太郎, 大内綾, 長岡伸一, 向井和男
    日本ビタミン学会第63回年会  2011/06  安田女子大学(広島市安佐南区)  日本ビタミン学会
     
    2-Ⅰ-14 6月4日(土)~5日(日)
  • リポソーム膜中におけるビタミン E のラジカル捕捉反応速度の測定  [Not invited]
    福澤健治, 柴田瑩, 大内綾, 長岡伸一, 向井和男
    日本ビタミン学会第63回年会  2011/06  安田女子大学(広島市安佐南区)  日本ビタミン学会
     
    2-Ⅰ-16 6月4日(土)~5日(日)
  • Development of Coincidence Spectrometer for Study of Collision Dynamics Between High-Energy Electron and Molecule  [Not invited]
    T. Ito, S. Inoue, M. Tahara, Y. Nakazato, H. Kubota, T. Kakiuchi, K. Mase, S. Nagaoka
    第27回化学反応討論会  2011/06  Tokyo Institute of Technology 
    1P9 6月8日(水) - 6月10日(金)
  • TD DFT法による分子内プロトン移動反応に関する研究  [Not invited]
    寺前裕之, 長岡伸一, 長嶋雲兵
    第14回理論化学討論会  2011/05  岡山大学創立五十周年記念館  理論化学研究会
     
    2P01 5月12日(木) ~ 14日(土)
  • LiHの分子軌道エネルギー準位図 -非経験的ハートリー・フォック法を用いて-  [Not invited]
    長嶋雲兵, 寺前裕之, 長岡伸一
    第14回理論化学討論会  2011/05  岡山大学創立五十周年記念館  理論化学研究会
     
    2P08 5月12日(木) ~ 14日(土)
  • Photofragmentation Dynamics of the cis-Hexafluorocyclobutane molecule at the F K-edge  [Not invited]
    中島徹, 岡田和正, 末光篤, 為則雄祐, 鈴木功, 長岡伸一
    日本化学会第91春季年会 東北地方太平洋沖大地震のため中止、但し発表は成立  2011/03  Kanagawa University  Chemical Society of Japan
     
    3D1-55 3月26日(土)~29日(火)
  • Standardization of the method for measuring total antioxidant capacities of foodstuffs and its application (4) Development of a singlet oxygen absorption capacity (SOAC)  [Not invited]
    岩崎裕子, 高橋慎吾, 相澤宏一, 稲熊隆博, 大内綾, 長岡伸一, 向井和男, 寺尾純二
    日本農芸化学会2011年度大会 東北地方太平洋沖大地震のため中止、但し発表は成立  2011/03  Kyoto Women's University  JSBBA
     
    3J16a07 3月25日(金)~28日(月)
  • Standardization of the method for measuring total antioxidant capacities of foodstuffs and its application (5) Assessment of singlet oxygen absorption capacity of carotenoid-rich vegetables  [Not invited]
    高橋慎吾, 岩崎裕子, 相澤宏一, 稲熊隆博, 大内綾, 長岡伸一, 向井和男, 寺尾純二
    日本農芸化学会2011年度年会 東北地方太平洋沖大地震のため中止、但し発表は成立  2011/03  Kyoto Women's University  JSBBA
     
    3J16a09 3月25日(金)~28日(月)
  • 垣内拓大, 田原雅士, 長岡伸一, 間瀬一彦
    PFシンポジウム要旨集  2011
  • Si KLL 共鳴オージェ電子スペクトルにおける分子性励起軌道の分離  [Not invited]
    鈴木功, 河野優太郎, 池田明弘, 樋口格, 為則雄祐, 高橋修, 大内孝雄, 上田潔, 長岡伸一
    第24回日本放射光学会年会放射光科学合同シンポジウム  2011/01  つくば国際会議場  日本放射光学会
     
    9P086 1月7日(金)~1月10日(月)
  • cis-ヘキサフルオロシクロブタンの炭素K端での光吸収と解離  [Not invited]
    梶谷祐美子, 中島徹, 岡田和正, 為則雄祐, 鈴木功, 長岡伸一
    第24回日本放射光学会年会放射光科学合同シンポジウム  2011/01  つくば国際会議場  日本放射光学会
     
    9P085 1月7日(金)~1月10日(月)
  • Kinetic study of the Prooxidant Effect of α-Tocopherol. Hydrogen Abstraction from Lipids by α-Tocopheroxyl Radical  [Not invited]
    大内綾, 石倉正治, 小西健介, 向井和男, 長岡伸一
    第49回電子スピンサイエンス学会年会(SEST2010)  2010/11  Nagoya University  SEST
     
    2B-06 11月11日(木)~13日(土)
  • Development of Apparatus for Auger Electron - Ion Coincidence (AEICO) Spectroscopy and Auger electron - Auger electron Coincidence(AEAECO) Spectroscopy of Gas Phase Using 5-keV Electron Gun  [Not invited]
    T. Kakiuchi, S. Inoue, M. Tahara, T. Itoh, H. Kubota, Y. Nakazato, K. Mase, S. Nagaoka
    International Conference on Many Particle Spectroscopy of Atoms, Molecules, Clusters, and Surfaces  2010/09  Tohoku University 
    P40 9月4日(土)-9月7日(火)
  • Site-selective ion desorption from CF3CH2OH dissociatively chemisorbed on Si(111) studied with photoelectron photoion coincidence (PEPICO) measurements  [Not invited]
    Takahiko Yamazaki, Shogo Hashimoto, Takuhiro Kakiuchi, Kazuhiko Mase, Shin-ichi Nagaoka, Masatoshi Tanaka
    International Conference on Many Particle Spectroscopy of Atoms, Molecules, Clusters, and Surfaces  2010/09  Tohoku University 
    P44 9月4日(土)-9月7日(火)
  • SiF4のSi1s励起オージェ遷移の研究  [Not invited]
    河野優太郎, 池田明広, 大井正則, 大内孝雄, 樋口格, 鈴木功, 為則雄祐, 上田潔, 高橋修, 長岡伸一
    第4回分子科学討論会2010  2010/09  大阪大学豊中キャンパス  分子科学会
     
    4P011 9月14日(火)~17日(金)
  • オージェ電子-光電子コインシデンス分光法によるSi(111)-7×7清浄表面の表面サイトを選択した局所価電子状態の研究  [Not invited]
    垣内拓大, 田原雅士, 長岡伸一, 間瀬一彦
    第4回分子科学討論会2010  2010/09  大阪大学豊中キャンパス  分子科学会
     
    2P056 9月14日(火)~17日(金)
  • Si3N4/Si(111)超薄膜の表面・界面・基板を選別した局所価電子状態の研究  [Not invited]
    田原雅士, 山口勝広, 垣内拓大, 間瀬一彦, 長岡伸一
    第4回分子科学討論会2010  2010/09  大阪大学豊中キャンパス  分子科学会
     
    2D11 9月14日(火)~17日(金)
  • 食品への応用をめざしたカロテノイドの一重項酸素消去活性評価法 (SOAC法) の開発  [Not invited]
    向井和男, 大内綾, 長岡伸一, 相澤宏一, 岩崎裕子, 稲熊隆博, 寺尾純二
    第24回カロテノイド研究談話会  2010/09  徳島大学付属病院  日本カロテノイド研究会 (国際カロテノイド学会日本支部)
     
    講演番号16 9月14日(火)-15日(水)
  • CH-O interaction in small acetaldehyde clusters studied with core-electron excitation spectroscopy in the carbon K-edge region  [Not invited]
    K. Tabayashi, Y. Tsutsumi, M. Chohda, Y. Tamenori, I. Higuchi, I. H. Suzuki, S. Nagaoka, T. Gejo, K. Honma
    International Conference on Many Particle Spectroscopy of Atoms, Molecules, Clusters and Surfaces (MPS2010)  2010/09  Tohoku University 
    P71 9月4日(土)-9月7日(火)
  • Si含有分子のKLL共鳴オージェ電子スペクトルに現れるK殻励起軌道の分裂  [Not invited]
    鈴木功, 河野優太郎, 池田明弘, 樋口格, 為則雄祐, 高橋修, 大内孝雄, 上田潔, 長岡伸一
    原子衝突研究協会第35回年会  2010/08  奈良女子大学  原子衝突研究協会
     
    Q11 8月9日(月)-11日(水)
  • Development of Multi Coincidence Spectrometer Using 5-keV Electron Gun  [Not invited]
    井上慎平, 田原雅士, 垣内拓大, 長岡伸一, 間瀬一彦
    第26回化学反応討論会 広島大学  2010/06  Hiroshima University 
    1P24 6月2日(水)~6月4日(金)
  • ビタミンK誘導体の遅延蛍光を用いた抗酸化活性評価  [Not invited]
    小原敬士, 光森亮太朗, 長岡伸一
    第63回日本酸化ストレス学会  2010/06  神奈川県県民ホール  日本酸化ストレス学会
     
    P-40 6月24日(木)~25日(金)
  • カロテノイドを中心とした、食品の一重項酸素消去活性評価法の確立  [Not invited]
    向井和男, 大内綾, 長岡伸一, 相澤宏一, 岩崎裕子, 稲熊隆博, 寺尾純二
    第63回日本酸化ストレス学会  2010/06  神奈川県県民ホール  日本酸化ストレス学会
     
    O-21 6月24日(木)~25日(金)
  • 一重項酸素寿命に及ぼす抗酸化剤-金ナノ粒子の影響  [Not invited]
    池田明広, 大倉さとみ, 小原敬士, 長岡伸一
    第63回日本酸化ストレス学会  2010/06  神奈川県県民ホール  日本酸化ストレス学会
     
    P-35 6月24日(木)~25日(金)
  • 分子内プロトン移動反応に関する理論的研究  [Not invited]
    寺前裕之, 長岡伸一, 長嶋雲兵
    第13回理論化学討論会  2010/05  北海道大学学術交流会館  理論化学研究会
     
    2P10 5月23日(日)~25日(火)
  • Highly luminiscent LB films of Ir(III) complex and clay for gas sensing  [Not invited]
    国吉勇司, 小原敬士, 長岡伸一, 田村堅志, 山岸晧彦, 佐藤久子
    日本化学会第90春季年会  2010/03  Kinki University  Chemical Society of Japan
     
    A0316
  • α-Tocopheroxylラジカルとアルカリ及びアルカリ土類金属イオンの錯体形成とα-Tocopherolのラジカル消去反応に及ぼす金属イオンの効果  [Not invited]
    大内綾, 藤井雅, 長岡伸一, 向井和男
    第21回ビタミンE研究会  2010/01  慶応大学共立キャンパス  ビタミンE研究会
     
    O-5 1/22-23
  • α-Tocopherolの酸化促進効果の速度論的研究:α-Tocopheroxylラジカルによる脂質の水素引き抜き反応速度の測定  [Not invited]
    大内綾, 石倉正治, 小西健介, 長岡伸一, 向井和男
    第21回ビタミンE研究会  2010/01  慶応大学共立キャンパス  ビタミンE研究会
     
    O-6 1/22-23
  • 堤勇樹, 田林清彦, 丁田充, 為則雄祐, 樋口格, 鈴木功, 長岡伸一, 下條竜夫, 本間健二
    日本放射光学会年会・放射光科学合同シンポジウム予稿集  2009/12
  • Stopped-Flow Kinetic Study of the Aroxyl Radical-Scavenging Action of Vitamin E in Membranes of Egg Yolk Phosphatidylcholine Liposomes  [Not invited]
    Kenji Fukuzawa, Akira Shibata, Hisatsugu Ichikawa, Aya Ouchi, Shin-ichi Nagaoka, Kazuo Mukai
    5th Joint Meeting of the Societies for Free Radical Research Australasia and Japan and A Joint Meeting with the Mutagenesis and Experimental Pathology Society of Australasia (Redox Processes in Chemistry, Biology and Medicine)  2009/12  University of Sydney 
    12/1-4
  • ビタミンEのラジカル消去反応に及ぼすアルカリ金属塩及びアルカリ土類金属塩の効果  [Not invited]
    大谷優希, 大内綾, 長岡伸一, 向井和男
    2009年日本化学会西日本大会  2009/11  松山  日本化学会中国四国支部
     
    1P073 11/7-8
  • Si(CH3)4及びSiF4のサイト選択的KLLオージェ遷移の研究  [Not invited]
    河野優太郎, 池田明広, 大内孝雄, 樋口格, 鈴木功, 為則雄祐, 上田潔, 高橋修, 長岡伸一
    2009年日本化学会西日本大会  2009/11  松山  日本化学会中国四国支部
     
    2P034 11/7-8
  • ユビキノールによるビタミンEラジカル再生反応における同位体効果  [Not invited]
    大内綾, 長岡伸一, 向井和男
    2009年日本化学会西日本大会  2009/11  松山  日本化学会中国四国支部
     
    2J21 11/7-8
  • ビタミンE光分解系におけるAOT油水界面でのビタミンCによる抗酸化挙動  [Not invited]
    池田明広, 小原敬士, 長岡伸一
    2009年日本化学会西日本大会  2009/11  松山  日本化学会中国四国支部
     
    2P034 11/7-8
  • 高エネルギー電子線励起に由来した内殻電子励起ダイナミクスを研究するための気体・表面試料用コインシデンス分光装置の開発  [Not invited]
    田原雅士, 井上慎平, 垣内拓大, 間瀬一彦, 長岡伸一
    2009年日本化学会西日本大会  2009/11  松山  日本化学会中国四国支部
     
    2P032 11/7-8
  • ビタミンKの蛍光の消光による抗酸化作用の評価  [Not invited]
    光森亮太朗, 小原敬士, 長岡伸一
    2009年日本化学会西日本大会  2009/11  松山  日本化学会中国四国支部
     
    2P033 11/7-8
  • Si L23VV オージェ電子スペクトル計算によるSiO2/Si(001)超薄膜の表面・界面局所価電子状態の研究  [Not invited]
    山口勝広, 垣内拓大, 間瀬一彦, 高橋修, 長岡伸一
    2009年日本化学会西日本大会  2009/11  松山  日本化学会中国四国支部
     
    2P031 11/7-8
  • Development of an Electron Electron Ion Coincidence Apparatus for Auger Photoelectron Coincidence Spectroscopy and Electron Ion Coincidence Spectroscopy, and its Application for Site-Specific Fragmentation of 2,2,2-Trifluoroethanol Chemisorbed on Si(111)  [Not invited]
    Takahiko Yamazaki, Shogo Hashimoto, Narihiko Fujita, Kazuhiko Mase, Masatoshi Tanaka, Makoto Okusawa, Takuhiro Kakiuchi, Shin-ichi Nagaoka
    International Symposium on the Physics of Excitation‐assisted Nano‐processes  2009/11  Wakayama 
    P-2 11/20-21
  • ユビキノールによるビタミンEの再生反応における量子論的効果  [Invited]
    長岡伸一
    京都大学理学研究科理論化学セミナー  2009/10  加藤研究室  京都大学理学研究科化学専攻加藤研究室
     
    10/15
  • Site-specific behavior in resonant Auger electron spectra of F3SiCH2CH2Si(CH3)3 in the Si K-shell excitation region  [Not invited]
    I.H. Suzuki, A. Nitta, H. Fukuzawa, K. Ueda, O. Takahashi, Y. Tamenori, S. Nagaoka
    11th International Conference on Electronic Spectroscopy and Structure (ICESS11)  2009/10  Nara, Japan 
    6BP02 October 6th to 10th
  • Study of local valence electronic states of Si3N4 grown on Si(111) and Si(001) using Auger photoelectron coincidence spectroscopy (APECS)  [Not invited]
    Takuhiro Kakiuchi, Masashi Tahara, Hiroki Ishida, Kazuhiko Mase, Shin-ichi Nagaoka
    11th International Conference on Electronic Spectroscopy and Structure (ICESS11)  2009/10  Nara, Japan 
    6AP06 October 6th to 10th
  • X-ray Absorption and Resonant Auger electron spectra of SiF4 and Si(CH3)4 in the Si K-shell excitation region  [Not invited]
    O. Takahashi, I.H. Suzuki, A. Ikeda, Y. Kono, T. Ouchi, K. Ueda, I. Higuchi, Y. Tamenori, S. Nagaoka
    International Workshop on Electronic Spectroscopy for Gas-phase Molecules and Solid Surfaces  2009/10  Matsushima, Miyagi 
    P46 10月12日(月)-10月15日(木)
  • イオン同時計測法による内殻励起パーフルオロシクロブタンの解離ダイナミクス  [Not invited]
    末光篤, 岡田和正, 寺島妙美, 為則雄祐, 鈴木功, 田林清彦, 長岡伸一
    第3回分子科学討論会  2009/09  名古屋大学東山キャンパス  分子科学会
     
    2P020 9月21日(月)~24日(木)
  • オージェ電子-光電子コインシデンス分光法を用いたSi3N4/Si(111)-8×8表面界面の局所価電子状態の研究  [Not invited]
    田原雅士, 垣内拓大, 山崎貴彦, 橋本章吾, 田中正俊, 間瀬一彦, 長岡伸一
    第3回分子科学討論会  2009/09  名古屋大学東山キャンパス  分子科学会
     
    1P077 9月21日(月)~24日(木)
  • 分子内プロトン移動反応に関する理論的研究  [Not invited]
    寺前裕之, 長岡伸一, 長嶋雲兵
    第3回分子科学討論会  2009/09  名古屋大学東山キャンパス  分子科学会
     
    2P111 9月21日(月)~24日(木)
  • Fragmentation processes of the K-shell excited perfluorocyclobutane molecule studied with an ion-ion coincidence technique  [Not invited]
    K. Okada, T. Terashima, M. Ikemoto, Y. Tamenori, I. H. Suzuki, K. Tabayashi, S. Nagaoka
    第25回化学反応討論会  2009/06  Ohmiya 
    2P05 6月1日(月)~3日(水)
  • 分子内プロトン移動反応に関する理論的研究(3)  [Not invited]
    寺前裕之, 長岡伸一, 長嶋雲兵
    日本コンピュータ化学会2009年春季年会  2009/05  東京工業大学大学院社会理工学研究科  日本コンピュータ化学会
     
    1P05 5月21(木)~22(金)
  • Antioxidant Behavior of Vitamin C for Photolysis of Vitamin E in AOT Reversed Micelle  [Not invited]
    池田昭広, 小原敬士, 長岡伸一
    日本化学会第92春季年会  2009/03  Nihon University  Chemical Society of Japan
     
    1PA-074 3月27日(金)~30日(月)
  • イオン同時計測法によるパーフルオロシクロブタンの炭素K端での解離  [Not invited]
    岡田和正, 寺島妙美, 池本真理子, 為則雄祐, 鈴木功, 田林清彦, 長岡伸一
    日本化学会第91春季年会  2009/03  日本大学理工学部(千葉県船橋市)  日本化学会
     
    1E6-47 3月27日(金)~30日(月)
  • オージェ電子-光電子コインシデンス分光法を用いたSi3N4/Si(111)-8×8界面表面のサイト選択的オージェ電子スペクトル測定による局所価電子状態の研究  [Not invited]
    田原雅士, 垣内拓大, 山崎貴彦, 橋本章吾, 田中正俊, 間瀬一彦, 長岡伸一
    日本化学会第90春季年会  2009/03  日本大学理工学部(千葉県船橋市)  日本化学会
     
    1E4-54 3月27日(金)~30日(月)
  • ビタミンEエマルジョンにおける一重項酸素発光寿命の油滴サイズ依存性  [Not invited]
    折口孝, 小原敬士, 長岡伸一
    日本化学会第89春季年会  2009/03  日本大学理工学部(千葉県船橋市)  日本化学会
     
    4D2-08 3月27日(金)~30日(月)
  • コインシデンス分光による内殻励起、オージェ緩和、イオン脱離の研究  [Not invited]
    間瀬一彦, 物構研, 総研大, 間宮, 森本(物構研, 小林, 瀬戸山(SAGA, LS, 奥平・張, 大岩, 笠井, 小笹, 片岡, 解良, 小野, 永松, 塩野入, 深川, 末吉, 藤井・浦, 角田, 中川, 細海, 満尾, 青木, 足立, 加藤, 鈴木・西, 根橋(千葉大工, 田中・大野, 藤田, 橋本, 山崎(横国大院工, 奥沢, 小山田, 岡田, 飯島(群馬大教育, 長岡・垣内, 田原(愛媛大理
    第26回PFシンポジウム  2009/03  エポカルつくば  PF
     
    2006S2-002 3月24日(火)~25日(水)
  • ビタミンEのラジカル消去反応に及ぼすアルカリ及びアルカリ土類金属塩の効果  [Not invited]
    大内綾, 長岡伸一, 阿部皓一, 向井和男
    第20回ビタミンE研究会  2009/01  奈良文化会館  ビタミンE研究会
     
    O-12 1月24日(土)・25日(日)
  • オージェ電子-光電子コインシデンス分光法を用いたSi3N4/Si(111)-8×8界面表面のサイト選択的オージェ電子スペクトル測定による局所価電子状態の研究  [Not invited]
    垣内拓大, 田原雅士, 山崎貴彦, 橋本章吾, 田中正俊, 間瀬一彦, 長岡伸一
    第22回日本放射光学会年会・放射光科学合同シンポジウム  2009/01  東京大学本郷キャンパス  日本放射光学会
     
    11P136 1月9日(金)~1月12日(月)
  • ユビキノールによるビタミンEラジカル再生反応におけるトンネル効果  [Not invited]
    大内綾, 長岡伸一, 向井和男
    第20回ビタミンE研究会  2009/01  奈良文化会館  ビタミンE研究会
     
    O-1 1月24日(土)・25日(日)
  • イオン同時計測法によるフッ素内殻励起パーフルオロシクロ ブタンの解離過程の研究  [Not invited]
    寺島妙美, 岡田和正, 池本真理子, 為則雄祐, 清水亜由美, 新田晃子, 長岡伸一, 鈴木, 功, 田林清彦
    2008年日本化学会西日本大会  2008/11  長崎大学  日本化学会中国四国支部
     
    2F-05 11/15-16
  • コインシデンス分光法による 凝縮F3SiCH2CD2Si(CH3)3のサイト選択的オージェ過程およびイオン脱離の研究  [Not invited]
    橋本章吾, 藤田斉彦, 垣内拓大, 間瀬一彦, 大下浄治, 長岡伸一, 田中正俊
    第49回真空に関する連合講演会  2008/10  くにびきメッセ(松江) 
    10月28-31日
  • 改良型電子−電子−イオンコインシデンス分光装置の開発とサイト選択的イオン脱離研究への応用  [Not invited]
    垣内拓大, 藤田斉彦, 橋本章吾, 間瀬一彦, 大下浄治, 長岡伸一, 田中正俊
    日本物理学会秋季大会  2008/09  岩手大学(盛岡)  日本物理学会
     
    22pPSA-21 9月20-23日
  • 解離イオン対の相関スペクトルでみるF 1s励起パーフルオロシクロブタンの解離  [Not invited]
    岡田和正, 寺島妙美, 池本真理子, 為則雄祐, 清水亜由美, 新田晃子, 鈴木, 功, 田林清彦, 長岡伸一
    第2回分子科学討論会  2008/09  福岡国際会議場  分子科学会
     
    4P045 9月24日(水)~27日(土)
  • 有機ケイ素分子の内殻光電子、オージェ電子スペクトルにおける原子サイト依存性  [Not invited]
    新田晃子, 清水亜由美, 長岡伸一, 為則雄祐, 福澤宏宣, 上田潔, 鈴木功
    第2回分子科学討論会  2008/09  福岡国際会議場  分子科学会
     
    2P047 9月24日(水)~27日(土)
  • 分子内プロトン移動反応に関する理論的研究(2)  [Not invited]
    寺前裕之, 藤田若菜, 長岡伸一, 長嶋雲兵
    日本コンピュータ化学会2008年秋季年会  2008/09  高知大学朝倉キャンパス  日本コンピュータ化学会
     
    2P03 9月27日(土)~28日(日)
  • パーフルオロシクロブタンのF 1s励起と解離  [Not invited]
    末光篤, 岡田和正, 為則雄祐, 鈴木功, 長岡伸一, 田林清彦
    第24回化学反応討論会  2008/06  北海道大学 
    1P19 6/2-4
  • ビタミンEの抗酸化活性に及ぼす生体金属イオンの効果  [Not invited]
    大内綾, 橋本悠, 長岡伸一, 阿部皓一, 向井和男
    第61回日本酸化ストレス学会学術集会  2008/06  国立京都国際会館  日本酸化ストレス学会
     
    一般講演29 6月19日(木)~20日(金)
  • アロエサポナリンIの紫外線防御と一重項酸素消去の機能  [Not invited]
    長岡伸一, 藤井亜紀子, 日野めぐみ, 竹本真唯, 保田三沙貴, 三島麻里子, 小原敬士, 桝本茜, 宇野英満, 長嶋雲兵
    第61回日本酸化ストレス学会学術集会  2008/06  国立京都国際会館  日本酸化ストレス学会
     
    P085 6月19日(木)~20日(金)
  • Anisotropic Fragmentation following the K-shell Excitation of Perfluorocyclobutane  [Not invited]
    K. Okada, A. Suemitsu, Y. Iwasaki, I. H. Suzuki, S. Nagaoka, T. Gejo, Y. Tamenori, K. Tabayashi, K. Ohno
    21st International Conference on X-Ray and Inner-Shell Processes (X08)  2008/06  Paris 
    Poster II - 29 6月22日~27日
  • 分子内プロトン移動反応に関する理論的研究  [Not invited]
    寺前裕之, 橋詰大志郎, 長岡伸一, 長嶋雲兵
    日本コンピュータ化学会2008春季年会  2008/05  東京工業大学  日本コンピュータ化学会
     
    1P17 5月22日(木)~23日(金)
  • ビタミンEの不均一系での抗酸化反応の速度論的研究  [Not invited]
    吉本摩耶, 小原敬士, 長岡伸一
    日本化学会第88春季年会  2008/03  立教大学池袋キャンパス  日本化学会
     
    4PC-063 3月26日(水)~30日(日)
  • ビタミンEを含むミセル系における一重項酸素発光寿命  [Not invited]
    折口孝, 菊地香織里, 小原敬士, 長岡伸一
    日本化学会第88春季年会  2008/03  立教大学池袋キャンパス  日本化学会
     
    3L4-12 3月26日(水)~30日(日)
  • コインシデンス分光による内殻励起、オージェ緩和、イオン脱離の研究  [Not invited]
    間瀬一彦, 物構研, JSTさきがけ, 総研大, 間宮, 森本(物構研, 垣内(総研大, 小林, 瀬戸山(SAGA, LS, 奥平・張, 大岩, 笠井, 小笹, 片岡, 解良, 小野, 永松, 塩野入, 深川, 末吉, 藤井・浦, 角田, 中川, 細海, 満尾(千葉大工, 田中・大野, 藤田, 橋本(横国大院工, 奥沢, 小山田, 岡田, 飯島(群馬大教育, 長岡(愛媛大
    第25回PFシンポジウム  2008/03  つくば  PF
     
    2006S2-002 3/18-19
  • パーフルオロシクロブタンのCおよびF 1s励起と解離  [Not invited]
    岡田和正, 末光篤, 岩崎義己, 田林清彦, 鈴木功, 長岡伸一, 下條竜夫, 為則雄祐, 大野啓一
    第21回日本放射光学会年会放射光科学合同シンポジウム  2008/01  立命館大学びわこ草津キャンパス  日本放射光学会
     
    14P056 1/12-14
  • Comparison between the Free-Radical-Scavenging Activities with Vitamin E and Ubiquinol in Biological Systems Based on the Reaction Rates  [Not invited]
    Kazuo Mukai, Aiko Tokunaga, Shingo Itoh, Yu Kanesaki, Keishi Ohara, Shin-ichi Nagaoka, Kouichi Abe
    5TH CONFERENCE OF THE INTERNATIONAL COENZYME Q10 ASSOCIATION  2007/11  Kobe Gakuin University 
    November 9-12
  • パーフルオロシクロブタンのフッ素内殻励起・解離  [Not invited]
    末光篤, 岡田和正, 長岡伸一, 清水亜由美, 新田晃子, 鈴木功, 田林清彦, 為則雄祐
    2007年日本化学会西日本大会  2007/11  岡山大学  日本化学会中国四国支部
     
    2C1-18 11月10日・11日
  • Photoinitiated Radical Reaction in the Vitamin E Emulsion  [Not invited]
    Keishi Ohara, Ayumi Shimizu, Yuki Wada, Shin-ichi Nagaoka
    電子スピンサイエンス国際会議、第46回電子スピンサイエンス学会年会合同討論会(ISESS-SEST2007)  2007/11  Shizuoka  SEST
     
    P16 11月6日(火)~11月9日(金)
  • 有機ケイ素分子の内殻励起によって誘起されるサイト選択的解離  [Invited]
    長岡伸一
    第11回SPring-8シンポジウム  2007/10  SPring-8  SPring-8
     
    「原子分子の内殻励起研究会」「軟X線実験技術研究会」 10/27-28
  • 有機ケイ素分子のサイト選択的解離へのサイト間結合距離依存性  [Not invited]
    福澤宏宣, Prümper Georg、Liu XiaoJing, Lischke Toralf, 上田潔, Harries James, 為則雄祐, 大下浄治, 長岡伸一
    第1回分子科学討論会2007仙台  2007/09  東北大学川内北キャンパス  分子科学会
     
    3P128 9月17日(月)~20日(木)
  • パーフルオロシクロブタンのフッ素K殻領域における吸収と解離過程  [Not invited]
    岡田和正, 末光篤, 長岡伸一, 清水亜由美, 新田晃子, 鈴木功, 田林清彦, 為則雄祐
    第1回分子科学討論会2007仙台  2007/09  東北大学川内北キャンパス  分子科学会
     
    1P139 9月17日(月)~20日(木)
  • 不均一系におけるビタミンEの光化学反応の研究  [Not invited]
    清水亜由美, 和田有紀, 小原敬士, 長岡伸一
    第1回分子科学討論会2007仙台  2007/09  東北大学川内北キャンパス  分子科学会
     
    3P100 9月17日(月)~20日(木)
  • カテキン類によるビタミンE再生作用の速度論的研究  [Not invited]
    新田晃子, 小原敬士, 長岡伸一, 向井和男
    第1回分子科学討論会2007仙台  2007/09  東北大学川内北キャンパス  分子科学会
     
    1P136 9月17日(月)~20日(木)
  • Site-specific fragmentation following Si:2p photoionization of organosilicon molecules studied by photoelectron-ion-ion triple coincidence spectroscopy  [Not invited]
    H. Fukuzawa, G. Prümper, X.-J. Liu, T. Lischke, K. Ueda, J. R. Harries, Y. Tamenori, J. Ohshita, S. Nagaoka
    International Symposium on (e,2e), Double Photoionization and Related Topics  2007/08  Königstein, Germany 
    1 - 4 August
  • 電子−イオン−イオン3重同時計測法で探る内殻イオン化分子のサイト選択的解離  [Not invited]
    福澤宏宣, Prümper Georg, 劉小井, Lischke Toralf, 上田潔, Harries James, 為則雄祐, 大下浄治, 長岡伸一
    原子衝突研究協会第32回研究会  2007/08  東京工業大学百年記念館  原子衝突研究協会
     
    P09 8月22日(水)-24日(金)
  • Vitamin E Emulsion系での一重項酸素寿命  [Not invited]
    折口孝, 小原敬士, 長岡伸一
    第29回日本フリーラジカル学会/ 日本過酸化脂質・フリーラジカル学会第31回大会 合同学会  2007/06  名古屋  日本フリーラジカル学会/ 日本過酸化脂質・フリーラジカル学会
     
    P27
  • α-Tocopherol懸濁系での抗酸化反応の速度  [Not invited]
    吉本摩耶, 小原敬士, 長岡伸一
    第29回日本フリーラジカル学会/ 日本過酸化脂質・フリーラジカル学会第31回大会 合同学会  2007/06  名古屋  日本フリーラジカル学会/ 日本過酸化脂質・フリーラジカル学会
     
    P26
  • Electron Ion Coincidence Measurements Using a 3D Momentum Resolving Mass Spectrometer  [Not invited]
    Georg Prümper, Hironobu Fukuzawa, Kiyoshi Ueda, Misaki Okunishi, Takuro Hatamoto, James Harries, Yusuke Tamenori, Shin-ichi Nagaoka
    第55回質量分析総合討論会  2007/05  Hiroshima 
    3A-S7-1435 5/15-17
  • Site-Specific Fragmentation Caused by Core-Level Photoionization of Organosilicon Molecules  [Invited]
    S. Nagaoka
    10th Hiroshima International Symposium on Synchrotron Radiation (第11回広島放射光国際シンポジウム)  2007/03  Higashi-Hiroshima  HiSOR
     
    「放射光を用いたナノサイエンスと光化学」 3/8-9
  • コインシデンス分光による内殻励起、オージェ緩和、イオン脱離の研究  [Not invited]
    間瀬一彦, 間宮, 森本, 垣内拓大, 小林, 奥平, 張, 大岩, 笠井, 小笹, 片岡, 解良, 小野, 永松, 塩野入, 深川, 末吉, 藤井, 浦, 角田, 中川, 細海, 満尾, 田中, 大野, 藤田, 奥沢, 小山田, 岡田, 飯島, 長岡伸一, 瀬戸山
    PFシンポジウム  2007/03  つくば  PF
     
    2006S2-002 3/14-15
  • 有機ケイ素分子の内殻励起によって誘起されるサイト選択的解離  [Invited]
    長岡伸一
    電子格子相互作用による緩和動力学の多様性:局在性、量子コヒーレンス、低次元系、非平衡系  2007/02  有馬温泉 
    2月11~12日
  • 軟X線による気体原子・分子内殻励起実験技術の新展開: 趣旨説明  [Invited]
    長岡伸一
    第20回日本放射光学会年会・放射光科学合同シンポジウム(JSR07)  2007/01  広島  日本放射光学会
  • ビタミンE同族体のミセル中におけるラジカル消去反応速度と生物活性の相関  [Not invited]
    向井和男, 徳永愛子, 伊藤慎吾, 兼崎友, 阿部皓一, 小原敬士, 長岡伸一
    第18回ビタミンE研究会  2007/01  佐世保  ビタミンE研究会
     
    P-01
  • Si:2pイオン化によって引き起こされるF3SiCH2CH2Si(CH3)3気体のサイト選択的イオンペア生成  [Not invited]
    竹本真唯, 長岡伸一, 日野めぐみ, Georg Prümper, 為則雄祐, James Harries, 鈴木功, 岡田和正, 田林清彦, Liu Xiao-Jing, Toralf Lischke, 上田潔
    第20回日本放射光学会年会・放射光科学合同シンポジウム(JSR07)  2007/01  広島  日本放射光学会
     
    1C005
  • 軟X線実験技術−サイト選択的解離の例−  [Invited]
    長岡伸一
    第10回SPring-8シンポジウム  2006/11  SPring-8  SPring-8
  • Site-Specific Fragmentation following Core-Level Photoionization of Molecules Studied by Electron-Ion Coincidence Spectroscopy  [Not invited]
    H. Fukuzawa, G. Prümper, X.-J. Liu, T. Lischke, K. Ueda, Y. Tamenori, J. Harries, T. Ibuki, S. Nagaoka
    International Symposium Scattering, Coincidence and Absorption Studies of Molecules (SCASM)  2006/09  Rio de Janeiro, Brazil 
    September 4-6
  • F3SiCH2CH2Si(CH3)3気体のサイト選択的解離の内殻準位依存性  [Not invited]
    竹本真唯, 長岡伸一, 日野めぐみ, Georg Prümper, 為則雄祐, James Harries, 鈴木功, 岡田和正, 田林清彦, Liu Xiao-Jing, Toralf Lischke, 上田潔
    分子構造総合討論会2006  2006/09  静岡  分子科学会
     
    3P127
  • Site-specific fragmentation following Si 2p photoionization of organosilicon molecules studied by electron-ion coincidence spectroscopy  [Not invited]
    H. Fukuzawa, G. Prümper, Y. Tamenori, J. Harries, X.-J. Liu, T. Lischke, K. Ueda, S. Nagaoka
    International Conference on Electronic Spectroscopy and Structure (ICESS)  2006/08  Foz do Iguaçu, PR, Brazil 
    P2AMO132 August 28th to September 1st
  • Site-specific fragmentation following F 1s photoionization of CF3SF5 molecules studied by electron-ion coincidence spectroscopy  [Not invited]
    H. Fukuzawa, G. Prümper, S. Nagaoka, T. Ibuki, Y. Tamenori, J. Harries, X.-J. Liu, K. Ueda
    International Conference on Electronic Spectroscopy and Structure (ICESS)  2006/08  Foz do Iguaçu, PR, Brazil 
    P2AMO81 August 28th to September 1st
  • Molecular Knife - Control of Chemical Reactions by Core Excitation  [Invited]
    S. Nagaoka
    Fourteenth International Conference on Composites/Nano Engineering (ICCE-14)  2006/07  Boulder, Colorado, USA 
    July 2-8
  • Doppler shift in resonant excitation of CF3SF5 probed by Auger electron spectroscopy  [Not invited]
    伊吹紀男, 伊藤伸一, 為則雄祐, 岡田和正, 長岡伸一, 森下雄一郎, 鈴木功
    第22回化学反応討論会  2006/06  Institute for Molecular Science 
    1A2
  • ビタミンEとユビキノール-10のフリーラジカル消去反応の構造活性相関  [Not invited]
    向井和男, 徳永愛子, 伊藤慎吾, 兼崎友, 小原敬士, 長岡伸一, 阿部皓一
    第28回日本フリーラジカル学会  2006/05  津  日本フリーラジカル学会
     
    O-08
  • ギ酸クラスターの内殻励起と誘起反応過程の研究  [Not invited]
    山本恵輔, 丸山友絵, 田林清彦, 岡田和正, 為則雄祐, 鈴木功, 長岡伸一, 下条竜夫, 田村孝, 伊勢田満広, 真部弘和, 本間健二, 田中大
    第19回日本放射光学会年会放射光科学合同シンポジウム  2006/01  名古屋  日本放射光学会
     
    9P083M
  • Si:2p イオン化によって引き起こされるF3SiCH2CH2Si(CH3)3気体のサイト選択的解離  [Not invited]
    日野めぐみ, 竹本真唯, 長岡伸一, Georg Prümper, 為則雄祐, James Harries, 鈴木功, 高橋修, 岡田和正, 田林清彦, Liu Xiao-Jing, Toralf Lischke, 上田潔
    第19回日本放射光学会年会放射光科学合同シンポジウム  2006/01  名古屋  日本放射光学会
     
    9C010N
  • F1s励起CF3SF5の解離におけるドップラーシフト  [Not invited]
    伊吹紀男, 伊藤伸一, 為則雄祐, 岡田和正, 長岡伸一, 森下雄一郎, 鈴木功
    第19回日本放射光学会年会放射光科学合同シンポジウム  2006/01  名古屋  日本放射光学会
     
    9P082M
  • 三つの化学シフト−NMR、ESCA、メスバウアー−  [Invited]
    長岡伸一
    日本分光学会中国四国支部愛媛地区講演会  2005/12  松山  日本分光学会中国四国支部
  • 同時計数法を用いた表面凝縮有機ケイ素分子のSi 2p 内殻イオン化に由来するサイト選択的オージェ崩壊過程とイオン脱離  [Not invited]
    垣内拓大, 間瀬一彦, 小林英一, 南部英, 高橋修, 長岡伸一
    第46回真空に関する連合講演会  2005/11  学習院大学
  • 同時計数法を用いた凝縮有機ケイ素分子のSi 2p 内殻イ オン化に由来するサイト選択的オージェ崩壊過程とイオン脱離  [Not invited]
    垣内拓大, 間瀬一彦, 小林英一, 南部英, 高橋修, 長岡伸一
    分子構造総合討論会2005東京  2005/09  東京  分子科学会
     
    1C12
  • 発光分光法とab initio分子軌道計算を用いたアロエサポナリンの励起状態の研究  [Not invited]
    竹本真唯, 日野めぐみ, 桝本茜, 宇野英満, 長嶋雲兵, 長岡伸一
    分子構造総合討論会2005東京  2005/09  東京  分子科学会
     
    1P118
  • F3SiCH2CH2Si(CH3)3におけるSi:1s電子の選択的イオン化による反応性の変動  [Not invited]
    日野めぐみ, 竹本真唯, 垣内拓大, 長岡伸一, 大下浄治, 岡田和正, 伊吹紀男, 鈴木功, 為則雄祐
    分子構造総合討論会2005東京  2005/09  東京  分子科学会
     
    2P106
  • 内殻領域における1,1-ジフルオロエチレンの光吸収スペクトルと解離イオンの角度分布  [Not invited]
    岡田和正, 伊吹紀男, 松戸誉央, 山名洋輔, 藤井亜紀子, 長岡伸一, 鈴木功, 田林清彦, 為則雄祐, 大野啓一
    分子構造総合討論会2005東京  2005/09  東京  分子科学会
     
    1P109
  • 蛍光検出法による懸濁液系での天然抗酸化剤のフリーラジカル消去速度測定  [Not invited]
    小原敬士, 仲原英紀, 長岡伸一
    分子構造総合討論会2005東京  2005/09  東京  分子科学会
     
    2P160
  • カテキン類のビタミンE再生作用  [Not invited]
    末光藍, 小原敬士, 長岡伸一, 向井和男
    第27回日本フリーラジカル学会学術集会  2005/06  岡山  日本フリーラジカル学会
     
    O-11
  • カテキン類の抗酸化作用  [Not invited]
    向井和男, 末光藍, 小原敬士, 長岡伸一
    AOB (Antioxidant Biofactor) 研究会  2005/06  徳島 
    6月17日
  • オージェ−光電子コインシデンス分光による凝縮SiF3CH2CH2Si(CH3)3のサイト選択的オージェ過程の研究  [Not invited]
    間瀬一彦, 南部英, 小林英一, 瀬尾淳哉, 垣内拓大, 高橋修, 大下浄治, 田中正俊, 長岡伸一
    日本物理学会第60回年次大会  2005/03  野田  日本物理学会
     
    24pWB-2
  • カテキン類によるビタミンE再生反応の速度論的研究  [Not invited]
    末光藍, 小原敬士, 長岡伸一, 向井和男
    日本化学会第85回春季年会  2005/03  横浜  日本化学会
     
    3A1-12
  • 電子-イオン同時計数法を用いた凝縮有機ケイ素分子のSi:2p内殻イオン化後のサイト選択的イオン脱離  [Not invited]
    垣内拓大, 長岡伸一, 間瀬一彦, 小林英一, 南部英, 大下浄治
    第18回日本放射光学会年会放射光科学合同シンポジウム  2005/01  鳥栖  日本放射光学会
     
    9P169
  • Ion Desorption Caused by N1s Core-Level Photoexcitation of N2O on Si(100) Surface  [Not invited]
    S. Nagaoka, K. Mase
    10th International Workshop on Desorption Induced by Electronic Transitions (DIET-10)  2004/11  Susono, Shizuoka
  • Flavonoidの抗酸化作用におけるトンネル効果の研究  [Not invited]
    垣内拓大, 小原敬士, 長岡伸一, 向井和男
    分子構造総合討論会  2004/09  広島  分子科学会
     
    3P077
  • アロエサポナリンの光化学反応の研究  [Not invited]
    日野めぐみ, 竹本真唯, 倉光誠, 藤井亜紀子, 長岡伸一, 桝本茜, 宇野英満, 長嶋雲兵
    分子構造総合討論会  2004/09  広島  分子科学会
     
    4P088
  • Suzuki I H, Morishita Y, Tamenori Y, Okada K, Ooyama T, Tabayashi K, Yamamoto K, Ibuki N, Oniki Y, Nagaoka S
    Meeting abstracts of the Physical Society of Japan  2004/08
  • ビタミンE及び関連分子の抗酸化反応、酸化促進反応、再生反応における水素量子アトミックス  [Invited]
    長岡伸一
    水素量子アトミックス研究会  2004/08  つくば
  • 岡田和正, 山名洋輔, 伊吹紀男, 藤井亜紀子, 長岡伸一, 島田由美子, 森下雄一郎, 為則雄祐, 鈴木功
    化学反応討論会講演要旨集  2004/06
  • ダブルミキシングストップトフロー法を用いた ビタミンCによるビタミンE再生反応の速度論的研究  [Not invited]
    垣内拓大, 小原敬士, 長岡伸一, 向井和男
    第26回日本フリーラジカル学会学術集会  2004/06  山形  日本フリーラジカル学会
     
    O05
  • 岡田和正, 山名洋輔, 伊吹紀男, 藤井亜紀子, 長岡伸一, 田林清彦, 島田由美子, 森下雄一郎, 為則雄祐
    日本化学会講演予稿集  2004/03
  • Mase K, Kobayashi E, Mori M, Arai H, Kobayashi Y, Terashima S, Okudaira K, Ueno N, Okusawa M, Nagaoka S
    Meeting abstracts of the Physical Society of Japan  2004/03
  • ビタミンEの抗酸化作用  [Invited]
    長岡伸一
    愛媛県立宇和島東高等学校  2004/01  宇和島  愛媛県立宇和島東高等学校
  • 励起状態における分子内プロトン移動反応の研究  [Invited]
    長岡伸一
    環境にやさしい色素・材料開発のための基礎的研究シンポジウム  2003/12  横須賀
  • 松戸誉央, 岡田和正, 伊吹紀男, 藤井亜紀子, 長岡伸一, 鈴木功, 田林清彦, 為則雄祐, 町田雅武
    日本化学会西日本大会講演予稿集  2003/10
  • 長岡伸一, 藤井亜紀子, 倉光誠, 日野めぐみ, 桝本茜, 宇野英満, 長嶋雲兵
    分子構造総合討論会講演要旨集(CD-ROM)  2003/09
  • 鈴木功, 岡田和正, 谷本修一郎, 藤井亜紀子, 長岡伸一, 伊吹紀男, 芳我裕一, 為則雄祐
    原子衝突研究協会研究会講演概要集  2003/08
  • アロエサポナリンの励起状態分子内プロトン移動における節面モデル  [Invited]
    長岡伸一
    分子科学研究所研究会「生体関連分子の水素結合とダイナミクスの新展開」  2003/07  岡崎  分子科学研究所
  • クルクミンのフリーラジカル消去活性の溶媒依存性とそのメカニズム  [Not invited]
    小原敬士, 水上渉, 徳永愛子, 長岡伸一, 向井和男, 宇野英満
    第25回日本フリーラジカル学会(東京)  2003/06  東京  日本フリーラジカル学会
     
    B38
  • 鈴木功, 岡田和正, 谷本修一郎, 藤井亜紀子, 長岡伸一, 伊吹紀男, 芳我裕一, 為則雄祐
    質量分析総合討論会講演要旨集  2003/05
  • 放射光によるサイト選択的解離  [Invited]
    長岡伸一
    五大学化学シンポジウム  2002/10  徳島
  • 放射光によるサイト選択的解離  [Invited]
    長岡伸一
    日本物理学会秋季大会  2002/09  春日井  日本物理学会
  • 鈴木功, 斎藤則生, 岡田和正, 藤井亜紀子, 長岡伸一, 伊吹紀男, 佐守真悟, 清水雄一郎, 大橋治彦
    原子衝突研究協会研究会講演概要集  2002/08
  • Site-Specific Fragmentation Caused by Core-Level Photoexcitation of 1,1,1-Trifluoro-2-Propanol-d1 on Surfaces  [Invited]
    S. Nagaoka
    International Workshop on Dynamics in Core-Excited Molecules (IWDCEM)  2002/08  Higashi-Hiroshima
  • 励起状態における分子内プロトン移動反応の研究  [Invited]
    長岡伸一
    第3回大つくば物理化学セミナー  2002/07  真岡(台風6号のために交通が遮断され中止)
  • 藤井亜紀子, 長岡伸一, 岡田和正, 伊吹紀男, 清水雄一郎, 為則雄祐, 大橋治彦, 斎藤則生, 鈴木功
    化学反応討論会講演要旨集  2002/06
  • 為則雄祐, 岡田和正, 吉田啓晃, 清水雄一郎, 藤井亜紀子, 長岡伸一, 伊吹紀男, 大橋治彦, 鈴木功
    化学反応討論会講演要旨集  2002/06
  • 長尾昌志, 向井孝三, 山下良之, 吉信淳, 長岡伸一, 田中慎一郎
    日本化学会講演予稿集  2002/03
  • Site-Specific Fragmentation Caused by Core-Level Photoexcitation on Surfaces  [Invited]
    S. Nagaoka
    International Symposium on Manipulation of Atoms and Molecules by Electronic Excitations (ISMAMEE)  2002/03  Tokyo
  • Suzuki I, Fujii A, Shimizu Y, Tamenori Y, Ohashi H, Okada K, Tanimoto S, Yoshida H, Ibuki T, Haga Y, Nagaoka S
    Meeting Abstracts of the Physical Society of Japan  2002
  • 2B1における表面上のサイト選択的解離研究の現状と展望  [Invited]
    長岡伸一
    UVSORワークショップ「ビームライン高度化」  2001/11  岡崎  UVSOR
  • 三谷修二, 小原敬士, 長岡伸一, 向井和男
    日本化学会中国四国・同九州支部合同大会講演要旨集  2001/10
  • 水上渉, 徳永愛子, 小原敬士, 長岡伸一, 向井和男, 宇野英満
    日本化学会中国四国・同九州支部合同大会講演要旨集  2001/10
  • 長岡伸一, 間瀬一彦, 中村有延, 長尾昌志, 吉信淳, 田中慎一郎
    分子構造総合討論会講演要旨集  2001/09
  • EUVを用いた有機ケイ素分子の原子分子操作  [Invited]
    長岡伸一
    EUVリソグラフィ(EUVL)マスク技術検討会  2001/09  東京
  • 伊吹紀男, 神森桂, 長岡伸一, 鈴木功, 清水雄一郎, 斎藤則生, 為則雄祐, 大橋治彦, 吉田啓晃
    化学反応討論会講演要旨集  2001/05
  • Suzuki I.H, Saito N, Nagaoka S, Ibuki T, Okada K, Simizu Y, Kamimori K, Sasaki J, Tamenori Y, Ohashi H
    Meeting abstracts of the Physical Society of Japan  2001/03
  • 武部光晴, 西奥義憲, 小原敬士, 長岡伸一, 向井和男
    光化学討論会講演要旨集  2000/09
  • Tanaka Shin-ichiro, Mase Kazuhiko, Nagaoka Shin-ichi, Kamada Masao
    Meeting abstracts of the Physical Society of Japan  2000/03
  • 内殻励起を用いた表面脱離の研究;分子メスへの応用を目指して  [Invited]
    長岡伸一
    第28回表面科学研究会  2000/02  つくば
  • 内殻励起を用いた表面脱離の研究;分子メスへの応用を目指して  [Invited]
    長岡伸一
    分子科学研究所研究会「内殼電子励起状態とダイナミックス−現状と展望−」  2000/01  岡崎  分子科学研究所
  • Investigation of Photoinduced Electron Transfer of the Model Vitamin E-Quinone System  [Invited]
    S. Nagaoka
    Photoconversion and Photosynthesis: Past, Present and Future Prospects  1999/11  Okazaki  Institute for Molecular Science
  • Molecular Knife - Control of Chemical Reactions by Core Excitation  [Invited]
    S. Nagaoka
    Interesting World of Physical Chemistry  1999/11  Kyoto
  • 下条竜夫, 間瀬一彦, 田中慎一郎, 長岡伸一
    分子構造総合討論会講演要旨集  1999/09
  • 西奥義憲, 小原敬士, 長岡伸一, 向井和男
    分子構造総合討論会講演要旨集  1999/09
  • Nagaoka Shinichi
    Meeting abstracts of the Physical Society of Japan  1999/09
  • 内殻励起を用いた表面脱離の研究;分子メスへの応用をめざして  [Invited]
    長岡伸一
    日本物理学会秋季大会  1999/09  盛岡  日本物理学会
  • Tunneling Effect in Antioxidant, Prooxidant, and Regeneration Reactions of Vitamin E  [Invited]
    S. Nagaoka, M. Inoue, C. Nishioka, Y. Nishioku, K. Mukai, U. Nagashima
    3rd International Conference on Low Temperature Chemistry  1999/07  Nagoya
  • 徳永愛子, 兼崎友, 小原敬士, 長岡伸一, 向井和男
    日本化学会講演予稿集  1999/03
  • 西奥義憲, 小原敬士, 長岡伸一, 向井和男
    ESR討論会講演要旨集  1998/10
  • 西奥義憲, 長岡伸一, 向井和男
    分子構造総合討論会講演要旨集  1998/09
  • 仙波伸得, 小原敬士, 長岡伸一, 向井和男, 植田一正, 杉本豊成
    分子構造総合討論会講演要旨集  1998/09
  • 長岡伸一, 間瀬一彦, 永園充, 田中慎一郎, 宇理須恒雄, 大下浄治, 長嶋雲兵
    分子構造総合討論会講演要旨集  1998/09
  • 中村有延, 新出義和, 向井和男, 長岡伸一
    分子構造総合討論会講演要旨集  1998/09
  • 沢田公平, 小野寺祥, 榎本裕之, 長岡伸一, 向井和男, 川波肇, 吉原正邦
    油化学討論会講演要旨集  1998/09
  • Nodal-Plane Model in Excited-State Intramolecular Proton Transfer of 2-(2-Hydroxyaryl)benzazoles  [Not invited]
    S. Nagaoka, J. Kusunoki, A. Nakamura, T. Fujibuchi, K. Mukai
    17th IUPAC Symposium on Photochemistry  1998/07  Barcelona  IUPAC
     
    PA-2
  • NAGAOKA S, MASE K, NAGASONO M, TANAKA S, URISU T
    Meeting abstracts of the Physical Society of Japan  1998/03
  • 友田 英幸, 山本 修太郎, 北嶋 弘一, 仲井 正徳, 長岡 伸一
    精密工学会大会学術講演会講演論文集  1998/03
  • 沢田公平, 小野寺祥, 榎本裕之, 長岡伸一, 向井和男, 川波肇, 吉原正邦
    日本化学会講演予稿集  1998/03
  • 内殻励起後の原子サイトに選択的な反応−放射光による化学反応制御−  [Invited]
    長岡伸一
    第2回広島放射光国際シンポジウム  1998/03  Higashi-Hiroshima  HiSOR
  • 楠木淳也, 藤淵図南, 向井和男, 長岡伸一
    分子構造総合討論会講演要旨集  1997/10
  • 西奥義憲, 長岡伸一, 向井和男
    分子構造総合討論会講演要旨集  1997/10
  • 西岡千帆, 角田小百合, 長岡伸一, 向井和男, 長嶋雲兵
    分子構造総合討論会講演要旨集  1997/10
  • 中村有延, 新出義和, 向井和男, 長岡伸一
    分子構造総合討論会講演要旨集  1997/10
  • 沢田公平, 小野寺祥, 榎本裕之, 長岡伸一, 向井和男, 川波肇, 吉原正邦
    油化学討論会講演要旨集  1997/10
  • Mase K, Nagasono M, Tanaka S, Urisu T, Nagaoka S
    Meeting abstracts of the Physical Society of Japan  1997/03
  • 西奥義憲, 長岡伸一, 向井和男
    日本化学会講演予稿集  1997/03
  • ビタミンEの抗酸化反応機構  [Invited]
    長岡伸一
    水素の科学:水素が作る構造と機能  1997/03  つくば
  • 向井和男, 渡辺恵子, 岡渉, 江川義史, 長岡伸一, 寺尾純二
    油化学討論会講演要旨集  1996/10
  • 兼崎友, 長岡伸一, 向井和男
    油化学討論会講演要旨集  1996/10
  • 藤淵図南, 長岡伸一, 大下浄治, 石川満夫, 小谷野猪之助
    分子構造総合討論会講演要旨集  1996/10
  • 楠木淳也, 藤淵図南, 向井和男, 長岡伸一
    分子構造総合討論会講演要旨集  1996/10
  • 長岡伸一, 間瀬一彦, 永園充, 田中慎一郎, 宇理須恒雄
    分子構造総合討論会講演要旨集  1996/10
  • 西岡千帆, 井上雅代, 向井和男, 長岡伸一
    分子構造総合討論会講演要旨集  1996/10
  • 内殻サイトに特有な分子解離  [Invited]
    長岡伸一
    分子科学研究所研究会「放射光とレーザーを併用した分子科学の展望」  1996/10  岡崎  分子科学研究所
  • ビタミンEのトンネル反応  [Invited]
    長岡伸一
    第2回低温化学セミナー「トンネル反応と生物効果」  1996/08  東海
  • 三室守, 山野由美子, 伊藤允好, 菊地浩人, 長岡伸一
    日本植物生理学会年会要旨集  1996/03
  • 内殻励起による解離プロセス  [Invited]
    長岡伸一
    電気学会「放射光による材料加工技術調査専門委員会」・応用物理学会「光励起プロセス委員会」合同研究会  1996/01  東京  電気学会
  • Effects of Node of Wave Function upon Excited-State-Intramolecular-Proton-Transfer of Hydrogen-Bonded Molecules  [Invited]
    S. Nagaoka
    Dynamic Studies of Hydrogen Atom Transfer Reactions  1996/01  Okazaki
  • 新出義和, 山本修太郎, 長岡伸一, 向井和男
    ESR討論会講演要旨集  1995/10
  • 井上啓一, 長岡伸一, 向井和男
    ESR討論会講演要旨集  1995/10
  • Si:2p Core-Level Photoexcitation and Photoionization of Organosilicon Molecules  [Not invited]
    S. Nagaoka, T. Fujibuchi, U. Nagashima, S. Kato, K. Takano, I. Koyano
    11th International Conference on Vacuum Ultraviolet Radiation Physics  1995/08  Rikkyo University
  • 井上雅代, 長岡伸一, 長嶋雲兵, 向井和男
    日本化学会中国四国・同九州支部合同大会講演要旨集  1995/09
  • 長岡伸一, 石原和彦, BARBARA P F
    分子構造総合討論会講演要旨集  1995/09
  • 極紫外光を用いた内殻励起後の原子サイトに特有の解離プロセスの研究  [Invited]
    長岡伸一
    分子科学研究所研究会「極紫外光プロセスの基礎」  1995/08  岡崎  分子科学研究所
  • 藤淵図南, 畠中誠二, 山本修太郎, 新出義和, 長岡伸一, 向井和男, 岡崎敏
    日本化学会講演予稿集  1995/03
  • 井上雅代, 長岡伸一, 向井和男, 長嶋雲兵
    日本化学会講演予稿集  1995/03
  • 新出義和, 長岡伸一, 向井和男
    日本化学会講演予稿集  1995/03
  • 石原和彦, 長岡伸一, SILVA C, WALHOUT P C, OLSON E C J, HOERMANN A, BARBARA P F
    日本化学会講演予稿集  1995/03
  • 尾方まゆみ, 長岡伸一, 向井和男
    日本化学会講演予稿集  1995/03
  • 江川義史, 長岡伸一, 向井和男, 河野善行, 高橋元次
    油化学討論会・研究発表会講演要旨集  1994/09
  • 井上啓一, 根立浩一, 田嶋邦彦, 長岡伸一, 向井和男
    ESR討論会講演要旨集  1994/09
  • 江川義史, 長岡伸一, 向井和男
    日本化学会講演予稿集  1994/03
  • 向井和男, 伊藤慎吾, 森本仁士, 長岡伸一
    油化学討論会・研究発表会講演要旨集  1993/11
  • 向井 和男, 大林 繁, 長岡 伸一, 小澤 太健展, 東 長雄
    ビタミン  1993/04
  • 三室守, 長嶋雲兵, 長岡伸一, 高市真一, 西村賢宣, 山崎巌, 加藤哲也
    日本生物物理学会年会講演予稿集  1992/10
  • 長岡伸一, 長嶋雲兵
    分子構造総合討論会講演要旨集  1992/09
  • 石原和彦, 長岡伸一, 向井和男, 北弘志, 金子豊
    日本化学会講演予稿集  1992/09
  • 山本修太郎, 田嶋邦彦, 長岡伸一, 向井和男
    日本化学会講演予稿集  1992/09
  • 伊藤昭則, 長岡伸一, 向井和男
    日本化学会講演予稿集  1992/09
  • 伊藤昭則, 長岡伸一, 向井和男
    日本化学会講演予稿集  1992/03
  • 村上大祥, 沢田公平, 長岡伸一, 長嶋雲兵, 向井和男
    日本化学会講演予稿集  1992/03
  • 山本修太郎, 長岡伸一, 向井和男, 伊藤昭則
    日本化学会講演予稿集  1992/03
  • 森本仁士, 菊池清治, 長岡伸一, 向井和男
    日本化学会講演予稿集  1992/03
  • 伊藤昭則, 長岡伸一, 向井和男, 星本悦司, 広田襄
    ESR討論会講演要旨集  1991/10
  • 森本仁士, 岡内優司, 長岡伸一, 向井和男
    油化学討論会・研究発表会講演要旨集  1991/10
  • 励起状態におけるプロトン移動反応の研究  [Invited]
    長岡伸一
    日本化学会第62秋季年会(第6回若い世代の特別講演会)  1991/09  札幌  日本化学会
  • 森本仁士, 岡内優司, 長岡伸一, 向井和男
    日本化学会講演予稿集  1991/03
  • 伊藤昭則, 長岡伸一, 向井和男, 長島雲兵, 斉藤真司
    日本化学会講演予稿集  1991/03
  • Investigation of Proton-Transferred Enol Tautomers in the Lowest Excited Triplet States of Methylsalicylate and Related Molecules  [Invited]
    E. Hoshimoto, S. Yamauchi, N. Hirota, S. Nagaoka
    Photoinduced Proton Transfer Dynamics in Chemistry, Biology, and Physics in Honor of Michael Kasha  1991/01  Tallahassee
  • 長岡伸一, 長嶋雲兵
    分子構造総合討論会講演要旨集  1990/10
  • 沢田公平, 向井和男, 長岡伸一, 福本洋二
    日本化学会講演予稿集  1990/09
  • 長岡伸一, 岡内優司, 長嶋雲兵, 向井和男
    生体機能関連化学シンポジウム講演要旨集  1990/05
  • Sakai Y, Min B.S, Takayanagi T, Wakiya K, Suzuki H, Hirayama T, Nagaoka S, Okuyama K, Kimura K
    年会講演予稿集  1990/03
  • Photoionization Efficiency Curves of Water-Ethylene Clusters  [Invited]
    T. Hirayama, S. Nagaoka, K. Kimura
    International Symposium on VUV-SX Physics and Chemistry  1989/07  Okazaki
  • 上田 潔, 長岡 伸一, 佐藤 幸紀, 繁政 英治, 小谷野 猪之助, 柳下 明, 早石 達司
    秋の分科会講演予稿集  1988/09
  • 平山 孝人, 長岡 伸一, 木村 克美
    秋の分科会講演予稿集  1988/09
  • Investigation of Fragmentation Processes following 3d Core Photoexcitation of Trimethylgallium in the Vapor Phase  [Not invited]
    S. Nagaoka, S. Suzuki, U. Nagashima, T. Imamura, I. Koyano
    3rd International Conference on Synchrotron Radiation Instrumentation  1988/08  Tsukuba
  • 佐藤 幸紀, 上田 潔, 長岡 伸一, 小谷野 猪之助, 繁政 英治, 長田 哲夫, 早石 達司, 柳下 明, 田中 健一郎
    年会講演予稿集  1988
  • Investigation of Fragmentation Processes following Core Photoionization of Organometallic Molecules in the Vapor Phase  [Not invited]
    S. Nagaoka, S. Suzuki, I. Koyano
    Fifth National Conference on Synchrotron Radiation Instrumentation  1987/06  Madison
  • Investigation of Fragmentation Processes Following Core Photoionization of Organometallic Molecules in the Vapor Phase  [Invited]
    S. Nagaoka
    28th Okazaki Conference on Solid State Chemistry with VUV Synchrotron Radiation  1987/02  Okazaki  Institute for Molecular Science
  • NMR Study of Molecular Dynamics in Some Hydrogen-Bonded Crystals  [Not invited]
    T. Terao, T. Akagi, S. Nagaoka, F. Imashiro, A. Saika, N. Hirota
    XXIInd Congress Ampere on Magnetic Resonance and Related Phenomena  1984/09  Irchel campus of the University of Zurich 
    10-15 September 1984, Irchel campus of the University of Zurich
  • Proton Transfer and Nonradiative Decay Processes of Salicylaldehyde  [Invited]
    S. Nagaoka, N. Hirota
    One-Day Discussion on Electron Transfer and Proton Transfer in the Excited State  1982/10  Okazaki  Institute for Molecular Science

MISC

Awards & Honors

  • 2019/12 Faculty of Science, Ehime University Science Research Encouragement Award
  • 2016/02 Society of Computer Chemistry, Japan Autumn Meeting 2015 Selected Paper
     A Study of Absorption and Fluorescence Spectra of o-Hydroxybenzaldehyde with TDDFT Method JPN japan_society 
    J. Comput. Chem. Jpn. 14, 209-210 (2015)
  • 2014/05 The Chemical Society of Japan CSJ Journal Report 2014
     A Revisit to Molecular Orbitals in H2+, LiH, HF, and Hybridization (Highlight Review) JPN official_journal 
    Chem. Lett. 41, 9-14 (2012)
  • 2012/11 Ministry of Agriculture, Forestry and Fisheries Food Action Nippon Award 2012
     Development of SOAC Method JPN publisher 
    受賞者: Faculty of Science;Ehime Universityhttp://syokuryo.jp/award/award12/list/development.html
  • 2012/09 BioMedLib The Top 20 Articles Published on the Same Topic
     A Study to Control Chemical Reactions Using Si:2p Core Ionization: Site-Specific Fragmentation official_journal 
    J. Phys. Chem. A 115, 8822-8831 (2011)
  • 2010/05 American Oil Chemists' Society Edwin Frankel Award
     Kinetic Study of the Prooxidant Effect of alfa-Tocopherol. Hydrogen Abstraction from Lipids by α-Tocopheroxyl Radical USA official_journal 
    Lipids 44, 935-943 (2009)
  • 2009/11 American Physical Society and American Institute of Physics November 2009 Issue of Virtual Journal of Ultrafast Science
     Site-Specific Behavior in De-Excitation Spectra of F3SiCH2CH2Si(CH3)3 in the Si 1s Excitation Region USA official_journal 
    J. Chem. Phys. 131, 164309 (8 pages) (2009)
  • 2009/07 Japan Synchrotron Radiation Research Institute SPring-8 Research Frontiers 2008
     A Molecular Knife – Control of Chemical Reactions using Core Ionization JPN publisher 
    SPring-8 Research Frontiers 2008, pp. 114-115
  • 2005/12 Elsevier The ScienceDirect TOP25 Hottest Articles
     Structure-Activity Relationship of the Tocopherol-Regeneration Reaction by Catechins JPN publisher 
    Free Radical Biol. Med. 38, 1243-1256 (2005)
  • 2004/10 The Vacuum Society of Japan The 29th Vacuum Technology Award
     Construction and Evaluation of Coaxially Symmetric Mirror Electron Energy Analyzer with High Sensitivity, and Its Application to Coincidence Spectroscopy JPN international_academic_award 
    J. Vac. Soc. Jpn. 46, 377-384 (2003)
  • 1991/09 The Chemical Society of Japan The 6th Young Scholar Lecturer
     Excited-State Proton-Transfer JPN japan_society 
    日本化学会第62秋季年会(第6回若い世代の特別講演会)、1991年9月22-25日、札幌
  • 1991/02 The Chemical Society of Japan Chemical Research Frontier VII
     The Simplest Chemical Reaction -Proton Transfer- JPN official_journal 
    Chem. Ind., 44, 182-187 (1991)
  • 1977/03 財団法人学徒援護会京都支部 勤労学生表彰
     JPN

Research Grants & Projects

  • A Study on Practical Use of Antioxidative Absorption Capacity Assay Method for Foods
    Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2018/04 -2021/03 
    Author : 長岡 伸一
     
    我々は、様々な抗酸化物質や食品成分が活性酸素の一つであるフリーラジカルを消去する能力を評価する方法(ARAC法)、同様に一重項酸素を消去する能力を評価する方法(SOAC法)、フリーラジカルにより酸化されたビタミンEを再生する能力を評価する方法(ATREC法)を開発してきた。本研究では、これらの方法を食品の抗酸化活性の評価方法として実用化することを目的とする。 本年度は、オリーブオイルなどの市販されている8種の食用油及びそれに含まれるビタミンE類のラジカル消去反応速度を測定して、ARAC値を得た。食用油の反応速度は、含まれるビタミンE類の濃度にそれぞれの反応速度を掛けた値の和にほぼ等しくなった。 さらに、8種の食用油及びそれに含まれるビタミンE類の一重項酸素消去速度を測定して、SOAC値を得た。ラジカル消去反応と異なり、一重項酸素消去反応速度は、含まれるビタミンE類の濃度にそれぞれの反応速度を掛けた値の和よりも大きくなった。これは、食用油に含まれる脂肪酸などの別の成分が一重項酸素消去に貢献しているためと考えられる。同様の実験を、ミセル中のパーム油と大豆抽出物について行った。パーム油を精製してビタミンE類の濃度を高めると、一重項酸素消去反応速度は含まれるビタミンE類の濃度にそれぞれの反応速度を掛けた値の和とほぼ等しくなった。 カテキン類のような柔らかい分子構造を持った分子について、密度汎関数法などを用いて構造最適化を行って、妥当なイオン化エネルギーを得る方法を開発した。得られたカテキン類のイオン化エネルギーは、酸化電位と良い相関を示した。また、ARAC,SOAC値との相関について議論した。
  • 文部科学省:科学研究費補助金(基盤研究(C))
    Date (from‐to) : 2015 -2017 
    Author : 長岡 伸一
  • 文部科学省:科学研究費補助金(挑戦的萌芽研究)
    Date (from‐to) : 2012 -2014 
    Author : 長岡 伸一
     
    本研究は、様々な抗酸化物質や食品が活性酸素の一つである一重項酸素を消滅させる能力を評価する実用的で汎用的な方法(Singlet Oxygen Absorption Capacity (SOAC法)および同様にフリーラジカルを消滅される能力を評価する方法(Aroxyl Radical Absorption Capacity (ARAC法)の開発を行い、新たな食品の抗酸化活性の分析方法として確立することを目的とする。申請書ではフリーラジカル消滅能力評価法をNovel Oxygen Radical Absorption Capacity (NORAC法)と命名したが、アメリカ農務省がORAC法から撤退したので名前の縁起が悪いため、ARAC法に名称を変更した。1.SOAC法の高度化汎用性が高くて効率の良いSOAC法の開発を進め、新しい種々の機能が明らかにされて注目されている天然抗酸化剤トコトリエノールなどとパーム油抽出物などの各種食品に適用し、ミセル系での一重項酸素消滅能力SOAC値を評価中である。また、アロエ含有化合物での励起状態分子内プロトン移動との相関を明らかにした。2.ARAC法の開発ストップトフロー法を用いて抗酸化剤や食品のフリーラジカル消去活性ARAC値を評価する方法を開発して論文を発表した。半減期の使用やフリーラジカルの適切なモデルの検討も行った。また、金属イオンが共存する場合の影響についても明らかにした。さらに、ユビキノール、ビタミンC、還元型ピロロキノリンキノン (PQQH2)とビタミンEが共存する場合の抗酸化作用の相乗効果を明らかにした。
  • 文部科学省:科学研究費補助金(基盤研究(B))
    Date (from‐to) : 2011 -2014 
    Author : 佐藤 久子, 長岡 伸一, 田村 堅志
     
    シクロメタレート型イリジウム(III)錯体は有機EL素子などの燐光型発光材料として注目されている。本申請者はこれまでに長鎖アルキル基を有する中性の両親媒性Ir(III)錯体のラングミュア・ブロジェット(LB)膜を製造し、それを気体センサー膜として用いることに成功した。今回この発展として、より長寿命で堅固な層構造をもつ発光性薄膜をめざして種々の陽イオン性Ir(III)錯体と剥離化した粘土鉱物(無機ナノシート)とのハイブリッド化の検討をおこない、多色化をめざした酸素センシングデバイスのための研究をおこなった。今年度は色調変化のためのlayer-by-layer人工積層方法の検討をおこなった。今年度搬入した有機合成装置を用いて、3種(赤、青、黄)のIr(III)錯体を合成した。次に3種類のIr(III)錯体を用いた交互積層LB膜の製造と、それらの積層順番による色調変化の可能性について検討した。特に、2種のIr(III)錯体を用いた交互積層LB膜の製造と、それらによる色調変化の可能性について検討した。まずは単独の錯体と粘土鉱物とのハイブリッドLB膜を用いて積層数と発光強度が比例する条件を確立した。次に異種の錯体が一定の順序で配列した複合膜を製造するために、layer-by-layer人工積層膜を製造した。このとき、積層後のLB膜が基板から剥離しないように積層方法の技術開発をおこない、2種類の錯体の人工積層法に成功した。2種類の錯体の積層順序の可能な組み合わせを試み、錯体間のエネルギー移動効率を検討した。また、それらのLB膜による酸素センシングによる多色化を試みた。これらの主な成果はNew. J. of Chem. 36, 2467-2471 (2012)において報告し、hot article および裏表紙に採用された。科学技術振興機構主催のイノベーションジャパンに採択された。
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 2007 -2008 
    Author : Shin-ichi NAGAOKA, Keishi OHARA
     
    励起状態における水素結合に沿ったプロトン移動は、正確な測定と定量的理論解析に適している。今回我々は、プロトン移動が重要な役割を示す生理活性物質に我々が提唱している理論モデルを適用できることを見いだした。また、さらに長波長領域の励起状態である一重項酸素消去における分子内水素結合を含む生体関連分子が示す役割を研究すると共に、逆に短波長領域である軟X 線領域にも研究のウイングを広げた。
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 2005 -2006 
    Author : Shin-ichi NAGAOKA, Kazuhiko MASE, Osamu TAKAHASHI
     
    With the aim of application to molecular knife, we studied site-specific fragmentation caused by core-ionization of organosilicon molecules (for example, F3SiCH2CH2Si(CH3)3, N2O, CF3SF5, and formic acid dimer (HCOOH)2 by means of electron-ion coincidence spectroscopy in the vapor phase and condensed phase. The ab initio molecular orbital method was used for the theoretical description.Site-specific fragmentation caused by Si:2p core-level photoionization. of F3SiCH2CH2Si(CH3)3 vapor was studied by means of high-resolution energy-selected-electron photoion-photoion triple-coincidence spectroscopy. F3SiCH2CH2+-Si(CH3)3+ ion-pairs were produced by the 2p photoionization of the Si atoms bonded to the three methyl groups, and SiF+-containing ion-pairs were produced by the 2p photoionization of the Si atoms bonded to the three F atoms.The site-specificity was reduced in the Si:1s ionization. The site-specific ion desorption caused by N:1s photoionization of N2O was not clearly revealed. The effective electron migration between the two nitrogen sites, which are connected with each other in N2O, would be responsible for the disappearance of the site-specificity for the ion desorption.
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(特定領域研究)
    Date (from‐to) : 2003 -2006 
    Author : Kazuo MUKAI, Kunihiko TAJIMA, Keishi OHARA, Shin-ichi NAGAOKA, Masaki MITO
     
    Human aging is induced by the reaction of lipid, protein, and nucleic acid with active oxygens and free radicals. Natural antioxidants such as vitamin E (α-, β-, γ-, δ-tocopherol, TocH), ubiquinol, vitamin C, polyphenols (flavones, catechins) etc., which exist in biological systems, scavenge active oxygens and free radicals quickly, and protect the aging. In the present work, the kinetic studies of i) free-radical-scavenging action, ii) tocopherol-regeneration action, and iii) singlet-oxygen-quenching action with the above natural antioxidants were performed, and several interesting results were obtained.1) The aroxyl-radical-scavenging rates (k_s) of vitamin E (α-, β-, γ-, δ-TocH) and ubiquinol were measured in micellar solutions by varying pH, using stopped-flow spectrophotometer. It has been clarified that ubiquinol shows higher and lower free-radical-scavenging activity than a-tocopherol in mitochondria of several tissues (heart, muscle, liver and brain) and in serum, respectively.2) Quenching rates (K_Q) of singlet oxygen (^1O_2) by 7 kinds of flavone derivatives and 4 kinds of catechins have been measured The K_Q values of several kinds of flavones and catechins were found to be larger than those of lipids, amino acids, and DNA. Further, these values are similar to those of a-and y-tocopherol, ubiquinol-10, and plastoquinol model, suggesting that these polyphenols may contribute to the protection of oxidative damage in biological systems, by quenching ^1O_2.3) In order to understand the dynamics of antioxidant actions of vitamin E (α-,β-, γ-, δ-TocH) in biological systems, kinetic study of the formation and decay reactions of vitamin E radicals (α-, β-, γ-, δ-tocopheroxyls, Toc) has been performed in organic solvents, using stopped-flow spectrophotometer. The second-order rate constants (k_f and 2k_d) for the formation and decay reactions of Toc were determined by comparing the observed curves with the simulation ones obtained by the numerical calculation of differential equations related to the above reactions. The k_f values decreased in the order of α-> β-~γ-> δ-TocH, and the 2kd values increased in the order of α-< β-< γ-< δ-Toc in ethanol. The wavelengths of absorption maxima (λmax^1) and molar extinction coefficients (ε_1) of the optical spectra (for example, i = 1~4 for α-Toc.) were determined for these radicals. The scheme of the decay reactions of α-, β-, γ-, δ-Toc radicals has been discussed based on the results obtained.4)The rate constant and activation energy of the regeneration reaction of natural vitamin E by vitamin C were determined with a double-mixingstopped-flow spectrophotometer. The kinetic effect ofmethyl substitution on the aromatic ring of vitamin E radical indicates that partial charge-transfer plays a role in the reaction Since a substantial deuterium kinetic isotope effect was not found, the tunneling effect may not play an important role under the present experimental conditions.
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(特定領域研究(B), 特定領域研究)
    Date (from‐to) : 1999 -2002 
    Author : Koji MAEDA, Yoichi KAMIURA, Jun-ichi KANASAKI, Shin-ichi NAGAOKA, Yuzo SHINOZUKA, Yohsuke KAYANUMA
     
    This priority area project carried out in 1998- 2001 FY aimed to elucidate, with cooperation of 8 research groups sharing common material systems and thoughts, the whole picture of the mechanisms of electronic excitation induced atomic movements in semiconductors thereby developing novel techniques for manipulating atoms and molecules with high controllability (selectivity) and efficiency in solid materials that are expected to be useful for realization of next generation devices. The materials actually studied have included typical semiconductors such as Si, C and GaAs, and the electronic excitation methods have been based on photon illumination (laser and X-ray), particle beams (electron and ion), current injection, and charge state control. The activities this year, devoted to summarizing the 3 years project, have included two committee meetings of group leaders, an open workshop, and publication of a News Letter. Through these activities, we have proposed a general guide line for enhancing the efficiency and : the selectivity of atomic and molecular manipulation by electronic excitations : The material systems efficiently controllable should be defect centers in semiconductors possessing inherent structural instability due to orbitally-degenerate excited states, light elements such as hydrogens with high mobility in the excited states, defects or surfaces with structural flexibility, and carbon solids with flexible orbital hybridization. The use of long lifetime two-hole states generated by high density excitations, cooperative excitations and parallel processes will also promote the efficiency of the primary excitations. Further, to attain the site-selectivity expected in localized excitations, it is necessary to suppress the spatial spread of the excited electrons (holes) in the extended band states.
  • 文部科学省:科学研究費補助金(特定領域研究(B))
    Date (from‐to) : 1999 -2001 
    Author : 長岡 伸一, 鎌田 雅夫, 信定 克幸, 田中 慎一郎, 間瀬 一彦, 関谷 徹司
     
    同じ元素の同じ内殻の準位でも、その原子の周囲の環境によって内殻電子の励起エネルギーは変化する。そこで、照射光のエネルギーを厳密に選ぶと、分子を構成する原子や表面上の原子のうち、特定の原子のみを選択的に励起することが可能である。その結果、その原子との結合だけが選択的に切れるようなサイト選択的解離反応を起こすことができる。放射光を用いると、こうした内殻電子の選択的な励起が可能になる。以上のような内殻励起の特徴と放射光の利点に基づいて、我々は、放射光による原子分子操作を研究した。内殻電子の局在性を利用すると、放射光を光のナイフとして用いた全く新しいタイプの材料加工技術を開発することができる。有機金属分子の内殻準位からの光イオン化後の解離反応は、半導体製造プロセスにおける光化学気相蒸着の観点からも興味深い。気体及び表面分子研究用の高感度高分解能電子・イオン同時計数装置3台を製作して性能評価を行い、旧型器に比べて分解能が大きく向上することがわかった。珪素単結晶においてSi:2p内殻電子イオン化と同時に生成する水素イオンについて予備的な結果を得た。本装置は、放射光励起によって放出される電子とイオンをそれぞれエネルギーと質量を選別して同時に検出する。本装置を用いると、内殻電子励起状態あるいはオージェ終状態を選別して、解離イオンの収量を定量的に測定することが可能であり、本研究の目的に最も適している。
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 1999 -2000 
    Author : Kazuo MUKAI, Keish OHARA, Shin-ichi NAGAOKA
     
    In the present work, we measured the rate constants of the reaction of peroxyl, tocopheroxyl, and aroxyl free radicals with natural antioxidants, such as catechins, caffeic acids and related compounds in homogeneous and micellar solutions, by using oxygen absorption method, stopped-flow spectrophotometer, and time-resolved ESR method. We have succeeded in obtaining the following interesting results :l) Detailed kinetic studies have been performed for the reaction of aroxyl (ArO ・) and 5,7-diisopropyltocopheroxyl (Toc ・ ) radicals with catechin, epicatechin, and related antioxidants in homogeneous and micellar solutions. The structure-activity relationship in the scavenging reaction of free radicals by catechin and epicatechin in solution was discussed. It has been found that catechin and epicatechin have high activity in vitamin E regeneration.2) The antioxidant activity of curcumin (1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione) was determined by inhibition of controlled initiation of styrene oxidation. Synthetic nonphenolic curcumins exhibited no antioxidant activity, therefore, curcumin is a classical phenolic chain-breaking antioxidant, donating H atoms from the phenolic groups not the CH_2 group as has been suggested (Jovanovic et al. J.Am. Chem. Soc., 121, 9677 (1999)).3) Studies of the kinetics of the proton- or hydrogen-transfer reactions concerning vitamin E in solutions and in micellar dispersions by means of stopped-flow and absorption spectroscopy indicated that proton tunneling plays an important role in the antioxidant and regeneration reactions that are advantageous in vivo but not as a part of the harmful prooxidant action.
  • 文部科学省:科学研究費補助金(特定領域研究(A))
    Date (from‐to) : 1998 -1998 
    Author : 長岡 伸一
     
    ビタミンEは、生体内で脂質過酸化ラジカルを消去して、過酸化をできるだけ抑制する作用を担っている。こうしたビタミンEの作用に関連した抗酸化反応、酸化促進反応、再生反応は、本質的にはプロ卜ンもしくは水素原子移動反応である。我々は、こうした反応においてトンネル効果が果たす役割の解明を目的として研究を行ってきた。本年度は特に、より生体系に近いミセル中におけるビタミンCやユビキノールによるビタミンEの再生反応に注目した。具体的には、ビタミンCやユビキノールの水酸基の水素を重水素化して、それらがミセル中でビタミンEラジカルのモデルを消去する反応速度やその温度変化をストップトフロー分光法を用いて求めた。実験結果には準古典的な効果では説明しきれない大きな重水素化効果が現れ、トンネル効果が生体中においても重要な役割を果たすことが示唆された。このほかにも、ビタミンE-ナフトキノン架橋分子を合成し、時間分解ESRなどを用いて、光励起分子の消去反応を逐次追跡することを試みた。我々が知る限りにおいて、溶液中と生体のモデル中でのビタミンEの反応におけるトンネル効果を研究しているのは、我々のグループのみである。本研究では、従来のビタミンEの反応の研究が注目してこなかったミクロな反応機構や反応のポテンシャル曲面の微視的な解析に光を当てることができた。
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 1997 -1998 
    Author : Shin-ichi NAGAOKA, Keishi OHARA, Kazuo MUKAI
     
    Proton transfer is a very simple chemical process readily accessible to both accurate measurement and quantitative theoretical analysis. We have constructed a simple theoretical model of the excited-state-proton-transfer, a model based on the nodal pattern of the wave function. In this project we have studied the application of our nodal-plane model to the following three problems.1. The substituent effect and the electronic-state dependence in the excited-state-intramolecular-proton-transfer (ESIPT) of o-hydroxybenzladehydes.2. The substituent-position effect in ESIPT of 2-(o-hydroxyaryl)benzazoles : Although both 2-(2-hydroxy- 3-aryl)benzazole and 2-(1-hydroxy- 2-aryl)benzazole consist of an aryl moiety, a benzazol-2-yl group, and an Oil group, their emission properties are very different.3. The substituent and solvent effects in ESIPT of aminoanthraquinones : The singlet-triplet energy-gap of the proton-transferred form is much less than that in the normal form.The experimental results obtained on the above three problems strongly support our nodal-plane model.Furthermore, we synthesized a bridged molecule of vitamin E and quinones, and studied the radical scavenging reaction of vitamin E.It is interesting that the microscopic electron behavior could manifest itself in the macroscopic vital-function.Although our nodal-plane model is a qualitative one, it allows us to recognize the important features of ESIPT immediately and provides useful information about the reaction mechanisms. Our nodal-plane model is applicable to photochemical reactions in various excited states of various molecules. Many chemists have cited it, and the usefulness of our explanation is recognized by many researchers.
  • 文部科学省:科学研究費補助金(重点領域研究)
    Date (from‐to) : 1997 -1997 
    Author : 長岡 伸一
     
    ビタミンEは、生体内で脂質過酸化ラジカルを消去して、過酸化をできるだけ抑制する作用を担っている。こうしたビタミンEの作用に関連した抗酸化反応、酸化促進反応、再生反応は、本質的にはプロトンもしくは水素原子移動反応である。我々は、こうした反応においてトンネル効果が果たす役割の解明を目的として研究を行ってきた。本年度は特に、ビタミンCやユビキノールによるビタミンEの再生反応に注目した。具体的には、ビタミンCやユビキノールの水酸基の水素を重水素化して、それらが溶液中でビタミンEラジカルのモデルを消去する反応速度やその温度変化をストップトフロー分光法を用いて求めた。実験結果には準古典的な効果では説明しきれない大きな重水素化効果やア-レニウスプロットからのずれが現れ、トンネル効果がこうした再生反応において重要な役割を果たすことが示された。このほかにも、ビタミンEの抗酸化反応の実験結果にトンネル効果が現れるにもかかわらず、その逆反応である酸化促進反応ではトンネル効果が現れない理由についても、分子軌道計算などに基づいて考察した。我々が知る限りにおいて、溶液中、生体中、あるいは生体のモデル中でのビタミンEの反応におけるトンネル効果を研究しているのは、我々のグループのみである。本研究では、従来のビタミンEの反応の研究が注目してこなかったミクロな反応機構や反応のポテンシャル曲面の微視的な解析に光を当てつつある。
  • 文部科学省:科学研究費補助金(重点領域研究)
    Date (from‐to) : 1996 -1996 
    Author : 長岡 伸一
     
    ビタミンEは、生体内で脂質過酸化ラジカルを消去して、過酸化をできるだけ抑制する作用を担っている。こうしたビタミンEの抗酸化反応は、本質的にはビタミンEから脂質過酸化ラジカルへのプロトンもしくは水素原子移動反応である。我々は、抗酸化反応においてトンネル効果が果たす役割の解明を目的として研究を行った。具体的には、ビタミンEの水酸基の水素を重水素化して、それらが溶液中で脂質過酸化ラジカルのモデルを消去する反応速度やその活性化エネルギーをストップフロー分光法を用いて求めた。実験結果には準古典的な効果では説明しきれない大きな重水素化効果が現れ、トンネル効果が抗酸化反応において重要な役割を果たすことが示された。それに対して、抗酸化反応の逆反応である酸化促進反応でのトンネル効果は小さいことがわかった。さらに、ビタミンCやユビキノールが抗酸化反応で生成したビタミンEラジカルを元に戻す再生反応などにおけるトンネル効果についても予備的な結果を得た。また、こうした情報を元にして、反応のポテンシャル図を求めて、理論計算の結果と比較することを試みている。我々が知る限りにおいて、溶液中、生体中、あるいは生体のモデル中での抗酸化反応におけるトンネル効果を研究しているのは、我々のグループのみである。本研究では、従来のビタミンEの抗酸化反応の研究が注目してこなかったミクロな反応機構や反応のポテンシャル曲面の微視的な解析に光を当てつつある。
  • 文部科学省:科学研究費補助金(重点領域研究)
    Date (from‐to) : 1993 -1993 
    Author : 向井 和男, 長岡 伸一
     
    1.3-(4-Chlorophenyl)-1,5-dimethyl-6-thioxoverdazylラジカル(p-CDTV)結晶における有機強磁性体の発見p-CDTVラジカルを合成・単離し、その結晶の磁化率(χ_M)をSQUID磁束計を用いてT=0.05K〜300Kの温度範囲で測定した。χ_MはT=0.70K近傍で急激な上昇を示し、さらに低温で飽和に達した。交流磁化率χ_もT=0.70Kでピークを示した。さらに、比熱(Cp)も0.70Kでλ型のピークを示し、また、磁場の増加と共にこのピークは消失し、ブロードな山が現れた。以上の結果からp-CDTVは強磁性キューリー温度T_c=0.70Kをもった、有機強磁性体であることが明らかとなった。T_c=0.70Kは有機強磁性体の中で2番目に高いキューリー温度である。2.1,5-Dimethyl-6-oxo-および-thioxo-verdazylラジカルの分子磁性表題のVerdazylラジカル類、約15種の合成に成功した。高温領域(77K〜300K)での磁化率(χ_M)測定結果は、これらのラジカルが、いずれも大きな負のWeiss定数(Θ)の値をもつことを示した。即ち、分子間には強い反強磁性交換相互作用(J)が働いていることが明らかとなった。3.有機フェリ磁性体の研究m-Phenylenebis(nitronylnitroxide)バイラジカルを合成し、ニトロキシドモノラジカルとの混晶の単結晶作成を試みた。現在までのところ、同一結晶中にモノラジカルとバイラジカルを同時に含む単結晶を得るには至っておらず、さらに、検討を行っている。
  • 文部科学省:科学研究費補助金(重点領域研究)
    Date (from‐to) : 1992 -1992 
    Author : 向井 和男, 長岡 伸一
     
    1)強磁性的交換相互作用を示す4種のPhenylgalvinoxylラジカル誘導体の発見Galvinoxylラジカルは分子間に強磁性的交換相互作用(J>O)が働くことが見い出された最初の例として知られている。しかしながら、この分子はT=85Kで結晶構造の変化を起こし、それにともなってラジカルスピンは互いに対を作り、反磁性となってしまう。そこで、Galvinoxylラジカルと似た不対電子分布を有し、分子間に強磁性的交換相互作用が働くことが期待されるPhenylgalvinoxylラジカル類5種を合成し、その磁化率の温度変化(300〜55K)を測定した。4種のラジカルが正のWeiss温度(Q>0)を示し、分子間のJが正であることが明らかにされた。従って、今後、極低温領域での磁気的性質の測定に大いに興味がもたれる。2)m-Phenylenebis(galvinoxyl)バイラジカルにおける強い分子間強磁性交換相互作用の出現Galvinoxyラジカル分子がPhenylene基のメタ位で互いに大共役したバイラジカルを合成し、その磁化率(χM)の温度変化を測定した。T<1bokで、χMはCurie-Weissの法則からはずれ、T=72KでχMT=2,87K・emu/molとなった。バイラジカルの分子間に大きな正の交換相互作用が働き、少くともS=9/2のスピン状態を作り出していなければならないことになる。現在、詳細な研究を行っている。3)有機ラジカルフエリ磁性体への試み基底三重項分子として知られるYang'sバイラジカル(S=1)とニトロキシドモノラジカル(S=1/2)からなる混晶を作成し、その磁気的性質の研究を行った。ESRの測定結果から、これらの分子が互いに混じり合った混晶を作ることが明らかになった。現在、磁化率の測定を試みている。
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(一般研究(B))
    Date (from‐to) : 1991 -1992 
    Author : Shin-ichi NAGAOKA, Umpei NAGASHIMA, Kazuo MUKAI
     
    The photoreaction of molecules depends largely on the nature of the excited state. It is interesting to study the relationship between the characteristics of the wave function of the excited state and the photoreaction, because such a study clarifies the effect of microscopic motion of electrons on the resultant photoreaction. The purpose of this project is to study the electronic-state dependence of photoreactions mainly by means of the emission spectroscopy. In order to perform this study, we made an emission spectrophotometer. We bought the spectrometer of the detection-side, the detector, and the controller. Previously, we had already bought the spectrometer of the excitation-side and the lamp. The sensitivity of the new spectrophotometer is much larger than the old one and the efficiency of the study was enhanced very much. We observed the fluorescence from the first and second excited singlet states of the related molecules of salicylaldehyde and discussed the electronic-state dependence of the proton transfer reaction. From theoretical studies, we found the effect of the node of the wave function on the photoreaction of organic molecules. Furthermore, we studied the proton transfer reactions in the triplet state and the ionic state of the related molecules of salicylaldehyde, the proton transfer in the lowest triplet states of 2-(2'-hydroxyphenyl)benzothiazole, 2-(2'-hydroxyphenyl)benzoxazole, and 2,2'-bipyridyl-3,3'-diol, the solvent effect on the relaxation processes of carotenoids showing dual emissive characteristics, the reason for the weak phosphorescence of pyridines. S. Nagaoka was chosen as 'Kagaku No Frontier VII' and 'the 6th Young Scholar Lecture' of the Chemical Society of Japan. He also wrote an invited paper in The Journal of Physical Chemistry published from the American Chemical Society (Vol. 95, pp. 10229-10235, 1991).
  • Ministry of Education, Culture, Sports, Science and Technology:Grants-in-Aid for Scientific Research(一般研究(C))
    Date (from‐to) : 1989 -1990 
    Author : Shin-ichi NAGAOKA, Inosuke KOYANO, Umpei NAGASHIMA, Takshi IMAMURA
     
    Metal ions are produced efficiently and selectively following photoionization from the metal-core orbital by using vacuum ultraviolet light. The purpose of the present investigation is to find the optimum condition for the efficient and selective production of the metal ions and to develop an efficient way of phorochemeical vapor deposition in the processes of semiconductor production.1. In the present investigation, it is necessary to use focused monochromatic vacuum-ultraviolet light with strong intensity. For this purpose, optics between the light source and the monochromator is of importance. Accordingly, we newly prepared a mirror system with high reflection on the basis of non-Gauusian optics and installed it in the TEPSICO-II apparatus of the BL3B beam line of the UVSOR synchrotron radiation facility in the Institute for Molecular Science. In the mirror system, the light intensity increased extremely and the efficiency of the investigation was improved.2. The metal ions and monomethyl-metal ions are produced following (n-l) d core ionization in various organometallic molecules with methyl groups. This fragmentation pattern can be explained in terms of the hybrid orbitals.3. In various organometallic molecules with methyl groups, the C ls ionization is followed by KVV Auger process and the fragmentation proceeds by way of the doubly charged parent ion. The metal-core ionization is followed by a cascade of Auger events, and the fragmentation proceeds by way of the higher multiply charged parent ions. The fragmentation patterns changes significantly depending on the site of the core electrons excited.4. The relative yield of ion pairs with aluminum ion are enhanced around the Al : 2p core ionization threshold in trimethylaluminum.
  • 文部科学省:科学研究費補助金(一般研究(C))
    Date (from‐to) : 1988 -1988 
    Author : 小谷野 猪之助, 長岡 伸一, 今村 隆史
     
    研究実施計画の線に沿って、イオン-分子反応の中間状態を観測する試みを種々の方法で進めた。反応イオンをできるだけ高濃度につくるためのデュオプラズマトロン型イオン源及びコルトロン型イオン源、生成したイオンを反応点に最大限に収束させるためのイオンレンズ、高効率集光系、及び高感度低ノイズ光検知器を設計・製作し既存のアルミニウム製真空槽に装着した。各部分の性能テストを行い、それぞれ満足に働くことが確認された。ついで、中間状態の検出の可能性を示す系を探るため、TESICO法(しきい光電子と反応生成物の時間相間を利用した測定法)による内部状態選択イオン-分子反応及び放電フロー法による振動励起イオンの脱活性反応の研究を行った。前者では酸素分子イオンとメタンの反応及びエチレンイオンとエチレンの反応をイオンの振動状態を選択して調べた。酸素イオンとメタンの系では、振動エネルギーの増加と共に発熱のチャネルであるCH_3O_2^+の生成がまず促進され、さらに振動エネルギーが上ると二つの吸熱チャネル(CH_3^+及びCH_4^+の生成)が促進されてくることがわかった。これらの結果の総合的解析から、この系は中間に二つ以上の異った構造をもつ複合体をつくって進み、その複合体の寿命がかなり長いこと、したがって、レーザー誘起けい光法による中間状態の検出が可能であることがわかった。エチレンの系では、二通りのモードの振動量子を別々に励起した測定から、これらモードの間に反応に及ぼす効果の差異があることが見いだされた。これも中間に寿命の長い中間複合体が存在することを示している。これらの系を対象に、レーザー誘起けい光法、レーザー照射によるイオン強度変動法による研究を行った。
  • Site-Specific Fragmentation Caused by Core Photoexcitation
    SPring-8:SPring-8 Construction and Operation (BL27SU)
    Date (from‐to) : 1985

Teaching Experience

  • General ChemistryGeneral Chemistry Ehime University

Committee Membership

  • 2007/03 -2011/01   The Chemical Society of Japan   Associate Editor of Chem. Lett.

愛媛大学教員活動実績

教育活動(B)

担当授業科目(B01)

  • 2019, the first semester, under graduate, 現代と科学技術
  • 2019, the first semester, under graduate, 現代と科学技術
  • 2019, the first semester, under graduate, 卒業研究Ⅰ
  • 2019, the first semester, under graduate, 量子化学Ⅰ
  • 2019, the first semester, under graduate, 量子化学Ⅱ
  • 2019, the first semester, under graduate, 量子化学ⅠA
  • 2019, the first semester, under graduate, 量子化学ⅡA


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