研究者業績
  1. 研究者検索結果一覧
  2. 南部 伸孝

南部 伸孝

ナンブ シンコウ  (Nambu Shinkoh)

基本情報

所属
上智大学 理工学部物質生命理工学科 教授
学位
博士（理学）(慶應義塾大学)
連絡先
shinkoh.nanbusophia.ac.jp
通称等の別名
Shinkoh NANBU
研究者番号
00249955
J-GLOBAL ID
200901062366264730
researchmap会員ID
1000144738

1988年4月-1994年3月
慶應義塾大学理工学部化学科，岩田末廣教授の指導のもと，電子励起状態の研究とともに核の運動に関する理論的研究を実施。
1994年4月-1997年3月
分子研理論研究系分子基礎理論第二，中村宏樹教授および，カナダのWaterloo大学，F. O. Goodman教授とともに共同研究を行い，非断熱遷移に特有な現象を利用した分子スイッチの可能性について提案。
1995年9月-2002年3月
計算科学研究センター，青柳睦前助教授（現在は，九州大学　情報基盤センター教授）とともに分子の高振動励起状態の研究を実施。
1999年6月-1999年12月
米国イリノイ州アルゴンヌ国立研究所にて訪問研究員として従事し，理論化学部門Stephen K. Gray教授のもと，多原子分子への応用が可能である遷移状態波束動力学計算の開発を実施。
1994年4月-現在
素反応過程の研究を中心に電子励起状態と反応動力学の研究を実施。特に，多自由度系への新展開を目指しプログラム開発を実施。一方，スーパーコンピュータの能力を活用し，機能分子，タンパク質の機能及び生理活性分子の探索を実施。

2015年-2016年　上智大学大学院　理工学研究科　理工学専攻　化学領域主任
2012年-2013年　上智大学大学院　学務委員会委員（理工委員）
2010年-2012年　上智大学大学院　理工学研究科　理工学専攻　化学領域主任
2012年 　上智大学　理工学部　推進委員
2012年-　上智大学　地球環境研究所員

(研究テーマ)
非断熱現象を利用した物質の機能発現と反応制御
分子高次系機能解明のための分子科学　－先端計測法の開拓による素過程的理解
光に応答する生体分子の非断熱動力学シミュレーション
温暖化関連ガス循環解析のアイソトポマーによる高精度化の研究（サブテーマ）理論計算によるアイソトポマー分別係数の決定
生体調整ペプチドの科学的基盤構築
アイソトポマーの計測・解析技術開発による物質循環解析
Photo-chemical reaction in condensed phase
生体分子の構造と光応答の相関に対する非断熱遷移動力学法によるアプローチ

(共同・受託研究希望テーマ)
フォトクロミック現象の理論的解明と応用

研究キーワード

 11

研究分野

 3

経歴

 4

学歴

 3

受賞

 2

論文

 134
  • Tatsuhiro Murakami, Manabu Nakazono, Alexey Kondorskiy, Toshimasa Ishida, Shinkoh Nanbu
    PHYSICAL CHEMISTRY CHEMICAL PHYSICS 14(32) 11546-11555 2012年  査読有り
    On-the-fly nonadiabatic ab initio molecular dynamics simulations have been carried out for three anionic species of indolylmaleimides (3-(1H-3-indolyl)-2,5-dihydro-1H-2,5-pyrroledione, IM) to clarify the mechanisms of photochemical reactions. The results are obtained for (i) a monovalent anion with a deprotonated indole NH group (IM-'), (ii) a monovalent anion with a deprotonated maleimide NH group (IM-'') and (iii) a divalent anion with doubly deprotonated indole and the maleimide NH groups (IM2-). Quantum chemical calculations are treated at the three state averaged complete-active space self-consistent field level for 6 electrons in 5 orbitals with the cc-pVDZ basis set (CAS (6, 5) SCF/cc-pVDZ). Molecular dynamics simulations are performed with electronically nonadiabatic transitions included using the Zhu-Nakamura version of the trajectory surface hopping (ZN-TSH) method. It is found that the nonadiabatic transitions occur accompanied by the stretching and shrinking motions of the N(7)-C(8) bond in the case of IM-' and the C(11)-N(12) bond in IM2- rather than the twisting motion of the dihedral angle. We also found that the ultrafast S-2 -> S-1 nonadiabatic transitions occur through the conical intersection (CoIn) right after photoexcitation to S-2 in IM-' and IM2-. Furthermore, the S-1 -> S-0 nonadiabatic transitions are found to take place in IM-'. It is concluded that IM2- would mainly contribute to the photoemission, because the S-1 <- S-0 and S-2 <- S-0 transitions of IM-'' are dipole-forbidden transitions and, moreover, IM2- is found to be the only species to stay in the S-1 state without non-radiative decay.
  • ZiLong Zheng, Yi Zhao, Manabu Nakazono, Shinkoh Nanbu
    Physical Chemistry Chemical Physics 14(9) 3017-3024 2012年1月  査読有り
  • Wilfredo Credo Chung, Shinkoh Nanbu, Toshimasa Ishida
    CHEMISTRY LETTERS 40(12) 1395-1397 2011年12月  査読有り
    The structural difference between rhodopsin and isorhodopsin is only in the cis-position of the chromophore, but the difference leads to a large discrepancy in photoisomerization period and quantum yield. The photoinduced cis-trans isomerization dynamics of the two chromophores are investigated using a Quantum Mechanics/Molecular Mechanics trajectory surface hopping scheme. Rhodopsin shows a straightforward and fast excited-state dynamics whereas the isorhodopsin dynamics in the excited state is complicated due to differences in retinal motions and space gaps formed by surrounding residues. Consequently, the isorhodopsin --> bathorhodopsin reaction is slower and less efficient. Photoexcitation of rhodopsin gives bathorhodopsin only, whereas isorhodopsin yields an analog with 9,11-di-cis-retinal in addition to bathorhodopsin. These differences explain why life uses rhodopsin rather than isorhodopsin.
  • Ikuo Tokue, Shinkoh Nanbu
    Chemical Physics Letters 514(4-6) 239-243 2011年10月  査読有り
  • Noriyuki Suzuki, Nozomu Ohara, Kosuke Nishimura, Yoshio Sakaguchi, Shinkoh Nanbu, Sohei Fukui, Hirotaka Nagao, Yoshiro Masuyama
    ORGANOMETALLICS 30(13) 3544-3548 2011年7月  査読有り
    The E isomer of a [5]cumulene derivative, 2,2, 9,9-tetramethyl-3,8-diphenyldeca-3,4,5,6,7-pentaene (1), which was previously believed to be unisolable owing to very fast E/Z isomerization, was isolated and structurally characterized. The Z isomer was trapped as the transition-metal complex 5, and the molecular structure was determined. DFT calculations and an electrochemical study on 1 are also described.
  • Ikuo Tokue, Shinkoh Nanbu
    The Journal of Chemical Physics 135(2) 024305 2011年7月  査読有り
  • Manabu Nakazono, Kenichiro Saita, Yuji Oshikawa, Kazushi Tani, Shinkoh Nanbu, Kiyoshi Zaitsu
    SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 78(2) 905-908 2011年2月  査読有り
    The fluorescence properties of 2-phenylindole, 2-naphthylindole and 2-anthracenylindole were investigated. 2-Anthracenylindole was newly synthesized by Suzuki-Miyaura's coupling. The fluorescence quantum yield of 2-phenylindole was the highest and the fluorescence emission maximum wavelength of 2-anthracenylindole was the longest. The ab initio quantum chemical calculation of the 2-anthracenylindole showed that the HOMO and LUMO of 2-anthracenylindole were localized in the anthracene moiety. (C) 2010 Elsevier B.V. All rights reserved.
  • Wei-Chen Chen, Shinkoh Nanbu, R. A. Marcus
    JOURNAL OF PHYSICAL CHEMISTRY A 114(36) 9700-9708 2010年9月  査読有り
    The wavelength-dependent isotopic fractionation of N2O is calculated, extending our previous work, Parts 1 and 2, in several aspects: (1) the fully three-dimensional ab initio electronic potential and transition dipole moment surfaces of S. Nanbu and M. S. Johnson (J. Chem. Phys. A 2004, 108, 8905) are used to calculate the absorption cross sections, instead of a 2D surface and (2) the vibrational frequencies and wave functions with anharmonicity correction are used for the ground electronic state. The results for the absorption spectrum and for the isotopic fractionation of the different isotopomers are discussed. One difference between experiments measuring the absorption coefficient (von Hessberg et al. Atmos. Chem. Phys. 2004, 4, 1237) and the others that measure instead the photodissociation is also discussed. Experiments on the quantum yield for wavelengths longer than 200 nm (>50 000 cm(-1)) would be helpful in treating the observed difference.
  • Manabu Nakazono, Hiroki Agawa, Shinkoh Nanbu, Kiyoshi Zaitsu
    LUMINESCENCE 25(5) 360-363 2010年9月  査読有り
    The chemiluminescence intensity of 1,2-di[3,4,5-tri(3,4,5-trihydroxybenzoyloxy)benzoyloxy] benzene increased in the presence of quaternary ammonium ions, such as acetylcholine chloride, choline chloride or benzyltrimethylammonium chloride. The complex of 1,2-di[3,4,5-tri(3,4,5-trihydroxybenzoyloxy)benzoyloxy] benzene with acetylcholine chloride, choline chloride or benzyltrimethylammonium chloride was investigated by (1)H-NMR spectroscopy. The structure of the complex formed from 1,2-di[3,4,5-tri(3,4,5-trihydroxybenzoyloxy)benzoyloxy] benzene with choline chloride was described by an ob initio quantum chemical calculation. Copyright (C) 2009 John Wiley & Sons, Ltd.
  • Wilfredo Credo Chung, Shinkoh Nanbu, Toshimasa Ishida
    JOURNAL OF PHYSICAL CHEMISTRY A 114(32) 8190-8201 2010年8月  査読有り
    The dynamics of the photoisomerization of a model protonated Schiff base of 9-cis retinal in isorhodopsin is investigated using nonadiabatic molecular dynamics simulation combined with ab initio quantum chemical calculations on-the-fly. The quantum chemical part is treated at the complete-active space self-consistent field level for six electrons in six active pi orbitals with the 6-31G basis set (CASSCF(6,6)/6-31G). The probabilities of nonadiabatic transitions between the S(1) ((1)pi pi*) and S(0) states are estimated in light of the Zhu-Nakamura theory. The photoinduced cis-trans isomerization of 9-cis retinal proceeds slower than that of its 11-cis analogue and at a lower quantum yield, confirming experimental observations. An energetic barrier in the excited state impedes the elongation and twist of the C(9)=C(10) stretch and torsion coordinates, respectively, resulting in the trapping of trajectories before transition. Consequently, the isomerization takes longer time and the transition more often occurs at smaller twist angle of =C(8)-C(9)=C(10)-C(11)=, which leads to regeneration of the 9-cis reactant. Thus, neither the smaller twist observed in the X-ray crystal nor the slower movement of nuclei in the transition region would be the main reason for the longer reaction time and lower yield. A well-known space-saving asynchronous bicycle pedal or crankshaft photoisomerization mechanism is found to be operational in 9-cis retinal. The simulation in vacuo suggests that the excited-state barrier and the photoisomerization itself are intrinsic properties of the visual chromophore and not triggered mainly by the protein environment that surrounds the chromophore.
  • Akinori Yamada, Shinkoh Nanbu, Yasuko Kasai, Minoru Ozima
    GEOCHIMICA ET COSMOCHIMICA ACTA 74(12) A1167-A1167 2010年6月  
  • Alexey Kondorskiy, Shinkoh Nanbu, Yoshiaki Teranishi, Hiroki Nakamura
    JOURNAL OF PHYSICAL CHEMISTRY A 114(21) 6171-6187 2010年6月  査読有り招待有り
    Theoretical ideas are proposed for laser control of chemical dynamics. There are the following three elementary processes in chemical dynamics: (i) motion of the wave packet on a single adiabatic potential energy surface, (ii) excitation/de-excitation or pump/dump of wave packet, and (iii) nonadiabatic transitions at conical intersections of potential energy surfaces. A variety of chemical dynamics can he controlled, if we can control these three elementary processes as we desire. For (i) we have formulated the semiclassical guided optimal control theory, which can he applied to multidimensional real systems. The quadratic or periodic frequency chirping method can achieve process (ii) with high efficiency close to 100%. Concerning process (iii) mentioned above, the directed momentum method, in which a predetermined momentum vector is given to the initial wave packet, makes it possible to enhance the desired transitions at conical intersections. In addition to these three processes, the intriguing phenomenon of complete reflection in the nonadiabatic-tunneling-type of potential curve crossing can also be used to control a certain class of chemical dynamics. The basic ideas and theoretical formulations are provided for the above-mentioned processes. To demonstrate the effectiveness of these controlling methods, numerical examples are shown by taking the following processes: (a) vibrational photoisomerization of HCN, (b) selective and complete excitation of the fine structure levels of K and Cs atoms, (c) photoconversion of cyclohexadiene to hexatriene, and (d) photodissociation of OHCl to O + HCl.
  • Yuko Nagai, Kenichiro Saita, Kenji Sakota, Shinkoh Nanbu, Masahiko Sekine, Munetaka Nakata, Hiroshi Sekiya
    JOURNAL OF PHYSICAL CHEMISTRY A 114(15) 5041-5048 2010年4月  査読有り
    Photoreactions of 7-hydroxyquinoline (7-HQ) in low-temperature (77-100 K) 2-methyltetrahydrofuran glass matrices are investigated using electronic spectroscopy. We have observed fluorescence excitation and fluorescence spectra of two long-lived species generated by irradiation of UV light (230-400 nm). The dominant species responsible for the fluorescence spectrum between 470 and 600 nm was assigned to the S(1)-> S(0) (pi pi*) transition of the keto form of cyclic 7-HQ dimer [(7-HQ)(2)] produced by excited-state double-proton transfer, the corresponding S(1)-S(0) fluorescence excitation spectrum of which was detected between 360 and 510 nm. Temperature dependence of the fluorescence excitation spectra showed the occurrence of keto -> enol isomerization in the So state of (7-HQ)(2) due to a back double-proton transfer. A very slow rate for the keto -> enol isomerization implies that the potential barrier height for the back double-proton transfer reacion is substantially high. Theoretical calculations at the MP2/aug-cc-pVDZ level of theory indicate that the enol and keto forms of cyclic (7-HQ)(2) are nonplanar, therefore a large change in the geometry is necessary for the back double-proton transfer. A second long-lived species that emits between 410 and 600 nm has been tentatively assigned to the D(3)(2A '') -> D(0)(1A '') transition of the 7-quinolinoxyl radical on the basis of calculated electronic transition energies for possible candidates obtained by MS-CASPT2/aug-cc-pVDZ level calculations as well as IR study of 7-HQ in argon matrices [Sekine, M.; Nagai, Y.; Sekiya, H.; Nakata, M. Phys. Chem. A 2009, 113, 8286]. Photoreaction processes leading to the two long-lived species have been discussed.
  • Ikuo Tokue, Shinkoh Nanbu
    JOURNAL OF CHEMICAL PHYSICS 132(2) 024301 2010年1月  査読有り
    The C approximate to B-1(2)-X approximate to (1)A(1) photoexcitation of SO2 was studied to investigate excited-state dynamics and the effects of the initial vibrational state. Ultraviolet photoabsorption cross sections (sigma's) of seven isotopologues (S-32 O-16(2), S-33 O-16(2), S-34 O-16(2), S-36 O-16(2), (SOO)-S-32-O-16-O-17, (SOO)-S-32-O-16-O-18, (SOO)-S-34-O-16-O-18) were computed using the wave packet propagation technique based on the three-dimensional potential energy surfaces of the X approximate to and C approximate to states, which were calculated using the ab initio molecular orbital configuration interaction method. Numerous wave packet simulations were carried out under the adiabatic approximation and used to calculate the sigma's of the seven isotopologues at 298 K; we concluded that the absorption spectrum of SO2 can be reliably modeled within the adiabatic framework based on the analysis of the time evolution of the wave packet. The calculated sigma's are in reasonable agreement with the recent experiment in the 190-228 nm region, and the isotope shifts of the peaks for S-33 O-16(2) and S-34 O-16(2) relative to the corresponding peaks for S-32 O-16(2) are in good agreement with the observed data. Relative to the sigma of S-32 O-16(2), isotopic substitution shows a significant increment for those of S-34 O-16(2) and S-36 O-16(2) in the 190-228 nm region. This trend is consistent with the observed data.
  • Qiao Sun, Sufan Wang, Hong Zhang, Zhen Li, Christoph Pifisterer, Stefan Fischer, Shinko Nanbu, Sean C. Smith
    AUSTRALIAN JOURNAL OF CHEMISTRY 63(3) 363-370 2010年  査読有り
    We present the results of a systematic series of constrained minimum energy pathway calculations on ground state potential energy surfaces, for a cluster model of the proton chain transfer that mediates the photocycle of the green fluorescent protein, as well as for a model including the solvated protein environment. The calculations vary in terms of the types of modes that are assumed to be capable of relaxing in concert with the movement of the protons and the results demonstrate that the nature and extent of dynamical relaxation has a substantive impact on the activation energy for the proton transfer. We discuss the implications of this in terms of currently available dynamical models and chemical rate theories that might be brought to bear on the kinetics of this important example of proton chain transfer in a biological system.
  • Hong Zhang, Sean C. Smith, Shinkoh Nanbu, Hiroki Nakamura
    AUSTRALIAN JOURNAL OF CHEMISTRY 63(3) 371-378 2010年  査読有り
    In this work, we study fluorination effects on atomic hydrogen interactions with the fluorinated corannulene radical (C(15)H(10)F(5)), which was built as a model for a partially fluorinated nanotube (or fullerene). Complete active space self-consistent field and multi-reference configuration interaction methods are employed to calculate the potential energy surfaces for both ground and excited electronic states, and the R-matrix quantum dynamics method is used to investigate the atomic hydrogen transmission and reflection dynamics through the five-membered ring in the fluorinated corannulene radical, which includes resonance effects as well as non-adiabatic transitions between the ground and excited electronic states. We also investigate hydrogen adsorptions at two sites in the middle five-membered ring, namely, on top of a carbon atom and in the middle of a carbon-carbon bond. We found that on carbon-top site, the adsorption is almost barrierless, whereas in the middle bond site, there is a barrier to hydrogen adsorption.
  • Manabu Nakazono, Ai Jinguji, Shinkoh Nanbu, Ryoichi Kuwano, Zilong Zheng, Kenichiro Saita, Yuji Oshikawa, Yuta Mikuni, Tatsuhiro Murakami, Yi Zhao, Shigeki Sasaki, Kiyoshi Zaitsu
    PHYSICAL CHEMISTRY CHEMICAL PHYSICS 12(33) 9783-9793 2010年  査読有り
    Various indolylmaleimides (IMs) were synthesized, and their fluorescence (FL) and chemiluminescence (CL) were measured. The substitution at the 2-position of the indole ring and the 3- or 4-position of the maleimide moiety caused an obvious change in the FL and CL of the IMs. An almost on-off switching of the FL of the IMs was observed. The intramolecular charge transfer from the indole moiety to the maleimide moiety occurred in 3-(1H-3-indolyl)-2,5-dihydro-1H-2,5-pyrroledione. In the FL of the IMs, CASPT2 calculations showed deprotonation of the NH group of the indole ring and the maleimide moiety at the excited state. The C=C bond in the maleimide moiety was needed for strong CL in the IMs without substitution at the 2-position of the indole ring. The relationships between the FL or CL properties and the structures of the IMs were clarified. These results provide significant information on the rational design of IMs as FL and CL probes.
  • Manabu Nakazono, Kenichiro Saita, Chika Kurihara, Shinkoh Nanbu, Kiyoshi Zaitsu
    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 208(1) 21-26 2009年11月  査読有り
    The synthesis and fluorescence property of 3-amino-N-(7'-methoxy-4'-methylcoumaryl)phthalimide (AMMP) are described. The fluorescence of AMMP originated during the intramolecular energy transfer from the coumarin moiety to the phthalimide moiety in various solvents. The ab initio quantum chemical calculation of the AMMP revealed that the HOMO and LUMO of AMMP were localized in the coumarin and phthalimide moieties, respectively. (C) 2009 Elsevier B.V. All rights reserved.
  • Sebastian O. Danielache, Shinkoh Nanbu, Carsten Eskebjerg, Matthew, S. Johnson, Naohiro Yoshida
    JOURNAL OF CHEMICAL PHYSICS 131(2) 024307 2009年7月13日  査読有り
  • Akinori Yamada, Shinkoh Nanbu, Yasuko Kasai, Minoru Ozima
    METEORITICS & PLANETARY SCIENCE 44(7) A223-A223 2009年7月  
  • M. Ozima, A. Yamada, O. Abe, S. Nanbu, Y. Kasai
    METEORITICS & PLANETARY SCIENCE 44(7) A164-A164 2009年7月  
  • Kenichiro Saita, Manabu Nakazono, Kiyoshi Zaitsu, Shinkoh Nanbu, Hiroshi Sekiya
    The Journal of Physical Chemistry A 113(29) 8213-8220 2009年5月  査読有り
  • Toshimasa Ishida, Shinkoh Nanbu, Hiroki Nakamura
    JOURNAL OF PHYSICAL CHEMISTRY A 113(16) 4356-4366 2009年4月  査読有り
    On-the-fly classical dynamics calculations combined with ab initio quantum chemical computations are carried out for two models of protonated Schiff base retinal in vacuo. The models are the 6 pi system of 2-cis-penta-2,4-dieneimminium cation and the 12 pi system in which two methyl groups are removed from the Schiff base of retinal. The CASSCF(6,6) level with the 6-31G basis set was employed for the quantum chemical part and the velocity Verlet algorism is utilized for time evolution of trajectories. The probabilities of nonadiabatic transition between the excited and ground state are estimated by the Zhu-Nakamura formulas. The 9-cis form product in addition to the all-trans one is generated in the present gas phase calculation for the 12,7 model, despite the 9-cis generation being suppressed in protein. We have found that energy relaxation on the ground state occurs in two steps in the 12 pi model. In the first step a metastable intermediate state is formed at similar to 100 fs after photoexcitation at the energy around 20-40 kcal/mol down from the excited potential energy surface, then it further relaxes to the energy around 60-80 kcal/mol from the excited surface, leading to the final state (second step). This relaxation pattern can be seen in all the three pathways to the all-trans, 9-cis, and (reverted) 11-cis form. Fourier transformation analysis reveals that the effective vibrational frequencies of the intermediate state are 1600-2000 cm(-1), which can be attributed to the conjugate CC bond frequencies in the electronic ground state. The two-step relaxation may be due to dynamical barriers. The two-step relaxation is not revealed in the smaller 6 pi model. The crank-shaft motion of the C11=C12 and C9=C10 bonds is found in the isomerization, which indicates the motion is intrinsic in retinal, not due to the surrounding protein. The branching ratio is about 1:1:2 for the all-trans, 9-cis, and 11-cis form generation. The ratio is different from earlier works where Tully's fewest switching scheme was employed. The bond length and the dihedral angle at the transitions are also analyzed to investigate the transition mechanism.
  • Hong Zhang, Sean C. Smith, Shinkoh Nanbu, Hiroki Nakamura
    JOURNAL OF PHYSICS-CONDENSED MATTER 21(14) 144209 2009年4月  査読有り
    In this work we study the transmission of atomic hydrogen across a fluorinated boron-substituted coronene radical (C(19)H(12)BF(6)) as a model for partially fluorinated and boron-doped nanotubes or fullerenes. Complete active space self-consistent field (CASSCF) and multi-reference configuration interaction (MRCI) methods are employed to calculate the potential energy surfaces for both ground and excited electronic states, and one-dimensional R-matrix propagation is utilized to investigate the transmission/reflection dynamics of atomic hydrogen, through the central six-member ring of the fluorinated boron-substituted coronene radical. The quantum scattering includes resonance effects as well as non-adiabatic transitions between the ground and excited electronic states. Within the sudden approximation, both centre and off-centre approach trajectories have been investigated. Implications for atomic hydrogen encapsulation by carbon nanotube and fullerene are discussed.
  • HUAN YANG, KE-LI HAN, SHINKOH NANBU, GABRIEL G BALINT-KURTI, HONG ZHANG, SEAN C SMITH, MARLIES HANKEL
    Journal of Theoretical and Computational Chemistry 8(01) 1003-1024 2009年  査読有り
  • Hiroki Agawa, Manabu Nakazono, Shinkoh Nanbu, Kiyoshi Zaitsu
    ORGANIC LETTERS 10(22) 5171-5174 2008年11月  査読有り
    Second generation polyphenol dendrimers (PDs) with different core molecules were synthesized, and their chemiluminescence (CL) was measured by reacting the PDs with H2O2 under alkaline conditions. All of the PDs showed a strong CL, more than 120-fold greater than that of gallic acid. Various CL intensities of the PDs were obtained using different core molecules in the PDs. The distance between each dendron in the PD structure is crucial in the PD CL intensity.
  • Huan Yang, Ke-Li Han, Shinkoh Nanbu, Hiroki Nakamura, Gabriel G. Balint-Kurti, Hong Zhang, Sean C. Smith, Marlies Hankel
    JOURNAL OF PHYSICAL CHEMISTRY A 112(34) 7947-7960 2008年8月  査読有り
    OCl/OH product branching ratios are calculated as a function of total energy for the 0(D-1) + HCl reaction using quantum wavepacket methods. The calculations take account of reaction on all the three electronic state potential energy surfaces which correlate with both reactants and products. Our results show that reaction on the excited electronic state surfaces has a large effect on the branching ratio at higher energies and that these surfaces must therefore be fully taken into account. The calculations use the potential energy surfaces of Nanbu and co-workers. Product vibrational and rotational quantum state distributions are also calculated as a function of energy for both product channels. Inclusion of the excited electronic state potential energy surfaces improves the agreement of the predicted product vibrational quantum state distributions with experiment for the OH product channel. For OCl agreement between theory and experiment is retained for the vibrational quantum state distributions when the excited electronic state potential energy surfaces are included in the analysis. For the rotational state distributions good agreement between theory and experiment is maintained for energies at which experimental results are available. At higher energies, above 0.7 eV of total energy, the OCl rotational state distributions predicted using all three electronic state potential energy Surfaces shift to markedly smaller rotational quantum numbers.
  • Hong Zhang, Marlies Hankel, Sean C Smith, Shinkoh Nanbu, Hiroki Nakamura
    The Journal of Physical Chemistry A 112(17) 4141-4147 2008年3月27日  査読有り
  • Kenichiro Saita, Seiya Kobatake, Tuyoshi Fukaminato, Shinkoh Nanbu, Masahiro Irie, Hiroshi Sekiya
    CHEMICAL PHYSICS LETTERS 454(1-3) 42-48 2008年3月  査読有り
    Two isomers of the closed-ring forms of 1,2-bis( 2,5-dimethyl-3-thienyl) perfluorocyclopentene (DMTF) having different S....S distances and dihedral angles between the two thiophene rings, are simultaneously observed in the FT-Raman spectrum by irradiation of UV light on microcrystals of the open-ring forms. Quantum chemistry calculations at the MP2/6-31G(d,p) level for several model clusters predict that an isomer having larger S....S distance is preferentially stabilized in crystal due to the electrostatic interaction between the two stacked thiophene rings of the closed-ring form and the open-ring form. (c) 2008 Published by Elsevier B. V.
  • Hiroshi Kohguchi, Toshinori Suzuki, Shinkoh Nanbu, Toshimasa Ishida, Gennady V Mil'nikov, Ponmile Oloyede, Hiroki Nakamura
    The Journal of Physical Chemistry A 112(5) 818-825 2008年2月  査読有り
  • Sebastian O. Danielache, Matthew S. Johnson, Shinkoh Nanbu, Mette M. -L. Grage, Chris McLinden, Naohiro Yoshida
    CHEMICAL PHYSICS LETTERS 450(4-6) 214-220 2008年1月  査読有り
    The fractionation of sulfur isotopes in the gas-phase reaction of OCS with OH was calculated by ab initio methods. The first reaction step occurs through a carbon bonded OH-OCS transition state. The activation barrier is 18.4 kJ mol(-1) (CCSD(T)/aug-cc-pVDZ level plus zero-point energy) relative to the reactants. Fractionation constants are -1.4, -2.6 and -6.3 parts per thousand for S-33, S-34 and S-36 respectively. These results bring new insight regarding the origin of stratospheric sulfate aerosols, including the identification of characteristic isotopic fractionations in the lower and middle stratosphere. (C) 2007 Elsevier B.V. All rights reserved.
  • Huan Yang, Ke-Li Han, Shinkoh Nanbu, Hiroki Nakamura, Gabriel G. Balint-Kurti, Hong Zhang, Sean C. Smith, Marlies Hankel
    JOURNAL OF CHEMICAL PHYSICS 128(1) 014308-1-014308-5 2008年1月  査読有り
    Quantum dynamical calculations are reported for the title reaction, for both product arrangement channels and using potential energy surfaces corresponding to the three electronic states, 1 (1)A('), 2 (1)A('), and 1 (1)A('), which correlate with both reactants and products. The calculations have been performed for J=0 using the time-dependent real wavepacket approach by Gray and Balint-Kurti [J. Chem. Phys. 108, 950 (1998)]. Reaction probabilities for both product arrangement channels on all three potential energy surfaces are presented for total energies between 0.1 and 1.1 eV. Product vibrational state distributions at two total energies, 0.522 and 0.722 eV, are also presented for both channels and all three electronic states. Product rotational quantum state distributions are presented for both product arrangement channels and all three electronic states for the first six product vibrational states. (c) 2008 American Institute of Physics.
  • Xuan Zhang, Yusuke Komoto, Kenji Sakota, Nakagaki Masayuki, Teruo Shinmyozu, Shinkoh Nanbu, Haruyuki Nakano, Hiroshi Sekiya
    CHEMICAL PHYSICS LETTERS 443(4-6) 194-198 2007年8月  査読有り
    The fluorescence excitation and dispersed fluorescence spectra of jet-cooled 4-dimethylamino-7-azaindole dimer are recorded to investigate the effect of a substitution of a diniethylamino group into the 4-position of the hydrogen atom of the 7-azaindole on the excited-state double proton transfer (ESDPT). The substitution of the dimethylamino group drastically suppresses the ESDPT reaction. (C) 2007 Published by Elsevier B.V.
  • Manabu Nakazono, Shinkoh Nanbu, Akihiro Uesaki, Ryoichi Kuwano, Manabu Kashiwabara, Kiyoshi Zaitsu
    ORGANIC LETTERS 9(18) 3583-3586 2007年8月  査読有り
    Various bisindolylmaleimides have fluorescence emission maxima wavelengths longer than 500 nm, large Stokes shifts longer than 200 nm, different fluorescence emission wavelengths at an excitation wavelength of 365 nm, and a long-lasting chemiluminescence. The expansion of the pi-conjugation, the pi-bond electronic structure, and oxidation of the CC bond at the 2,3-position of the maleimide moiety are crucial for producing these fluorescence and chemiluminescence properties.
  • 南部 伸孝, 安島 英孝, 三好 永作, 古屋 謙治, 杉本 学, 青木 百合子, 中園 学, 阿川 寛樹, 財津 潔, 浦崎 渚, 益田 美子, 池田 浩人
    九州大学情報基盤センター広報 : 全国共同利用版 6(3) 211-228 2007年3月  
  • Ikuo Tokue, Shingo Ebina, Megumi Kanai, Shinkoh Nanbu
    JOURNAL OF CHEMICAL PHYSICS 126(4) 044313-1-044313-10 2007年1月  査読有り
    Transition probabilities were evaluated for the X (1)A(1)-A B-1(1) and A B-1(1)-B (1)A(1) systems of GeH2 and GeD2 to analyze the X -> A -> B photoexcitation. Franck-Condon factors (FCFs) and Einstein's B coefficients were computed by quantum vibrational calculations using the three-dimensional potential energy surfaces (PESs) of the X (1)A(1), A B-1(1), and B (1)A(1) electronic states and the transition dipole moments for the X-A and A-B systems. The global PESs were determined by the multireference configuration interaction calculations with the Davidson correction and the interpolant moving least squares method combined with the Shepard [Proceedings of the 1968 23rd ACM National Conference (ACM, New York, 1968)] interpolation. The barriers to linearity correcting the spin-orbit interaction are evaluated to be 22 000 cm(-1) for the X state, 6300 cm(-1) for the A state, and 560 cm(-1) for the B state. The obtained FCFs for the X-A and A-B systems indicate that the bending mode is strongly enhanced in the excitation since the equilibrium bond angle greatly varies within the three states. The photoexcitation and fluorescence spectra calculated for the X-A system agree well with the observed spectra. The theoretical lifetimes for lower vibrational levels of the A and B states were calculated from the fluorescence decay rates for the A-X, B-A, and B-X emissions, and the lifetimes for the A state are in good agreement with the observed values except those affected by predissociation. (c) 2007 American Institute of Physics.
  • Hiroyuki Tamura, Shinkoh Nanbu, Toshimasa Ishida, Hiroki Nakamura
    JOURNAL OF CHEMICAL PHYSICS 125(3) 034307-1-034307-10 2006年7月  査読有り
    Laser control schemes of reactions of photoswitching functional molecules are proposed based on the quantum mechanical wave-packet dynamics and the design of laser parameters. The appropriately designed quadratically chirped laser pulses can achieve nearly complete transitions of wave packet among electronic states. The laser parameters can be optimized by using the Zhu-Nakamura theory of nonadiabatic transition. This method is effective not only for the initial photoexcitation process but also for the pump and dump scheme in the middle of the overall photoswitching process. The effects of momentum of the wave packet crossing a conical intersection on the branching ratio of products have also been clarified. These control schemes mentioned above are successfully applied to the cyclohexadiene/hexatriene photoisomerization (ring-opening) process which is the reaction center of practical photoswitching molecules such as diarylethenes. The overall efficiency of the ring opening can be appreciably increased by using the appropriately designed laser pulses compared to that of the natural photoisomerization without any control schemes. (c) 2006 American Institute of Physics.
  • Tokue, I, S Nanbu
    JOURNAL OF CHEMICAL PHYSICS 124(22) 224301-1-224301-10 2006年6月  査読有り
    Transition probabilities were evaluated for the X (1)Sigma(+)-A (1)Pi system of AlNC and AlCN isomers to analyze photoabsorption and fluorescence spectra. The global potential energy surfaces (PESs) of the X (1)Sigma(+) and A (1)Pi (1 (1)A('),2 (1)A(')) electronic states were determined by the multireference configuration interaction calculations with the Davidson correction. Einstein's B coefficients were computed by quantum vibrational calculations using the three-dimensional PESs of these states and the electronic transition moments for the X-1 (1)A(') and X-2 (1)A(') systems. Einstein's B coefficients obtained for AlNC or AlCN exhibit that the Al-N or Al-C stretching mode is strongly enhanced in the transition. The absorption and fluorescence spectra calculated for the X-1 (1)A(') and X-2 (1)A(') systems are discussed comparing with the observed photoexcitation and fluorescence spectra. The lifetimes for the several vibrational levels of the A (1)Pi state were calculated to be ca. 7 ns for AlNC and 21-24 ns for AlCN from the fluorescence decay rates of the 1 (1)A(')-X and 2 (1)A(')-X emissions. (c) 2006 American Institute of Physics.
  • Hidekazu Watanabe, Shinkoh Nanbu, Zhi-Hong Wang, Mutsumi Aoyagi
    CHEMICAL PHYSICS LETTERS 424(1-3) 133-138 2006年6月  査読有り
    The surface oxidation reaction, H2O + Si(100)-(2 x 1), has been studied by an ab initio molecular orbital method with the approximation of the cluster model. The rate-determining process is ascribed to the OH migration from the metastable state, and the temperature dependence of the rates of Oatom insertion reactions forming back bonding and top layer is estimated from the barrier height of each transition state. This reaction is found to occur much faster than the quenching by thermal relaxation and the arrival to the equilibrium condition. (c) 2006 Elsevier B.V. All rights reserved.
  • Shinkoh Nanbu, Toshimasa Ishida, Hiroki Nakamura
    CHEMICAL PHYSICS 324(2-3) 721-732 2006年5月  査読有り
    A novel usage of the non-adiabatic effects is proposed. In this proposal, atomic hydrogen penetrates through a five-membered carbon ring with the help of the non-adiabatic tunneling phenomenon. The cyclopentadienyl radical (C5H5) and pentaboron-substituted corannulenyl radical (C15H10B5) are used to illustrate the mechanism. To demonstrate the proposal, first principles calculations are performed for the non-adiabatic dynamics on potential energy surfaces determined by multi-reference configuration interaction method. The results show that the non-adiabatic transitions between the ground and excited states essentially control the hydrogen atom transmission through the five-membered ring of a pentaboron-substituted corannulenyl radical. It is found that the transmission occurs more than once out of four incidences when an appropriate initial wave packet is chosen. The phenomenon can be interpreted in terms of the Zhu-Nakamura semiclassical theory of non-adiabatic transitions. (c) 2005 Elsevier B.V. All rights reserved.
  • H Zhang, SC Smith, S Nanbu, H Nakamura
    JOURNAL OF PHYSICAL CHEMISTRY A 110(16) 5468-5474 2006年4月  査読有り
    The Lanczos homogeneous filter diagonalization method has been employed to compute the HOC] ro-vibrational states for a range of total angular momenta (J = 0, 1, 5, 10, 11, 20, 30) on a newly developed ab initio potential energy surface by Nanbu et al. (J. Theor. Comput. Chem. 2002, 1, 263). For such computationally challenging calculations, a parallel computing strategy has been incorporated into our method to perform the matrix-vector multiplications. For the computed low bound states, a spectroscopic assignment has been made and the widely used approximate adiabatic rotation method has been tested for the broad range of total angular momenta for this deep-well system. Comparison of experimental results with exact quantum mechanical calculations for the selected far-infrared transitions involving the range of total angular momenta has been made possible for the first time.
  • Nobuaki Koga, Masahiko Hada, Kenro Hashimoto, Haruo Hosoya, Toshio Matsushita, Hidenori Matsuzawa, Umpei Nagashima, Shinkoh Nanbu, Keiko Takano, Shinichi Yamabe
    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 231 2006年3月  査読有り
  • Tokue, I, K Yamasaki, S Nanbu
    JOURNAL OF CHEMICAL PHYSICS 124(11) 114308-1-114308-10 2006年3月  査読有り
    Dissociations after the A B-1(1)-> B (1)A(1) photoexcitation of SiH2, SiHD, and SiD2 were studied to investigate excited-state dynamics and effects of the initial vibrational state. The cross section (sigma) for the photodissociation relative to SiH2(B)-> Si(D-1)+H-2 and the rovibrational population of the H-2 fragment were computed using the wave packet propagation technique based on the three-dimensional potential energy surfaces (PESs) of the A and B electronic states and the transition dipole surfaces, which were reported in our previous paper [J. Chem. Phys. 122, 144307 (2005)]. The photodissociation spectrum consists of a broadband and a number of sharp peaks. For SiH2 and SiD2, the sharp peaks correspond to the resonance structure of the vibrational levels of the B state and the broadbands are nearly independent of the photon energy. The broadband for SiHD increases steeply with the photon energy above 30 000 cm(-1). The flux leaving the computational grid for SiH2 and SiD2 consists of at least two components, whereas that for SiHD consists of only a faster component. These large isotope effects were discussed based on the valley to the dissociation channel on PES and the difference in the position of the initial wave packet for three isotopomers. (c) 2006 American Institute of Physics.
  • H Tamura, S Nanbu, T Ishida, H Nakamura
    JOURNAL OF CHEMICAL PHYSICS 124(8) 084313-1-084313-13 2006年2月  査読有り
    Reaction mechanisms of the ultrafast photoisomerization between cyclohexadiene and hexatriene have been elucidated by the quantum dynamics on the ab initio potential energy surfaces calculated by multireference configuration interaction method. In addition to the quantum wave-packet dynamics along the two-dimensional reaction coordinates, the semiclassical analyses have also been carried out to correctly estimate the nonadiabatic transition probabilities around conical intersections in the full-dimensional space. The reaction time durations of radiationless decays in the wave-packet dynamics are found to be generally consistent with the femtosecond time-resolution experimental observations. The nonadiabatic transition probabilities among the ground (S-0), first (S-1), and second (S-2) excited states have been estimated by using the semiclassical Zhu-Nakamura formula considering the full-dimensional wave-packet density distributions in the vicinity of conical intersections under the harmonic normal mode approximation. The cyclohexadiene (CHD) ring-opening process proceeds descending on the S-1(1 B-1) potential after the photoexcitation. The major part of the wave-packet decays from S-1(1 B-1) to S-1(2 (1)A) by the first seam line crossing along the C-2-symmetry-breaking directions. The experimentally observed ultrafast S-1-S-0 decay can be explained by the dynamics through the S-1-S-0 conical intersection along the direction toward the five-membered ring. The CHD: hexatriene (HT) branching ratio is estimated to be approximately 5:5, which is in accordance with the experiment in solution. This branching ratio is found to be mainly governed by the location of the five-membered ring S-1-S-0 conical intersection along the ground state potential ridge between CHD and HT.
  • H Watanabe, ZH Wang, S Nanbu, J Maki, T Urisu, M Aoyagi, K Ooi
    CHEMICAL PHYSICS LETTERS 412(4-6) 347-352 2005年9月  査読有り
    The reported oxidation reaction observed by BML-IRRAS spectra on the silicon surface system, 2H + H2O/Si(1 0 0), has been studied by an ab initio molecular orbital method. The highest transition state is found at approximate to+25 kJ/mol from the reactant energy level, and the oxidation occurs easily under the experimental condition. The present study also accounts for the reactivity deduced from the absorption bands in the IR spectra. It is noted that the quenching of the reaction by thermal relaxation is impossible because the surface is not trapped into the metastable states located much lower in energy than the reactant. (c) 2005 Elsevier B.V. All rights reserved.
  • R. Tero, N. Misawa, H. Watanabe, S. Yamamura, SHINKOH NANBU, Y. Nonogaki, T. Urisu
    e-Journal of Surface Science and Nanotechnology 3(9) 237-243 2005年6月  査読有り
    Single molecular layer of avidin is fabricated on an atomically flat SiO2 surface and characterized by atomic force microscopy (AFM) and infrared reflection absorption spectroscopy. Immobilization of avidin is performed as follows; i) ester-modification of the surface by silane-coupling agent, ii) carboxylation by hydrolysis in HCl and iii) amide bonding between the surface -COOH and -NH2 in avidin molecules. Large dome structures (∼60 nm height) are formed after the ester-modification, but an atomically flat surface is obtained after the hydrolysis reaction. AFM topographs and function-recognizing images show that the each of avidin molecules adsorbs as a single molecule and retains the biotin-binding activity. Formation of a tethered bilayer membrane of a biotinylated phospholipid on the avidin layer is also described. [DOI: 10.1380/ejssnt.2005.237]
  • JI Choe, SK Chang, S Lee, S Nanbu
    JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM 722(1-3) 117-123 2005年5月  査読有り
    Stable molecular conformations were calculated for the 1,3-dimethyl ether of p-tert-butylcalix [4] crown-5-ether (1) in the various conformers and their potassium-ion complexes. The structures of three distinct conformations have been optimized using ab initio RHF/6-31G methods. After geometry optimizations, B3LYP/6-31 +G(d,p) single point calculations of the final structures are done to include the effect of electron correlation and the basis set with diffuse function and polarization function. Relative stability of free host I is in following order: cone (most stable)> partial-cone > 1,3-altemate conformer. For two different kinds of complexation mode, the potassium cation in the crown-5-ether moiety (cr) has much better complexation efficiency than in the benzene-rings (bz) pocket for all three kinds of conformation of host molecule 1. The relative stability of complex (1 + K(+)) in the cr-binding mode is in following order: cone similar to 1,3-alternate > partial-cone conformer. (c) 2005 Elsevier B.V. All rights reserved.
  • Tokue, I, K Yamasaki, S Nanbu
    JOURNAL OF CHEMICAL PHYSICS 122(14) 144307-144316 2005年4月  査読有り
    Transition probabilities were evaluated for the (X) over tilde (1)A(1)-(A) over tilde B-1(1) and (A) over tilde B-1(1)-(B) over tilde (1)A(1) systems of SiH2 and SiD2 to analyze the (X) over tilde ->(A) over tilde ->(B) over tilde photoexcitation. The Franck-Condon factors (FCFs) and Einstein's B coefficients were computed by quantum vibrational calculations using the three-dimensional potential energy surfaces (PESs) of the SiH2((X) over tilde (1)A(1),(A) over tilde B-1(1),(B$) over tilde (1)A(1)) electronic states and the electronic transition moments for the (X) over tilde-(A) over tilde, (X) over tilde-(B) over tilde, and (A) over tilde-(B) over tilde system. The global PESs were determined by the multireference configuration interaction calculations with the Davidson correction and the interpolant moving least-squares method combined with the Shepard interpolation. The obtained FCFs for the (X) over tilde-(A) over tilde and (A) over tilde-(B) over tilde systems exhibit that the bending mode is strongly enhanced in the excitation since the equilibrium bond angle greatly varies with the three states; the barrier to linearity is evaluated to be 21 900 cm(-1) for the (X) over tilde state, 6400 cm(-1) for the (A) over tilde state, and 230-240 cm(-1) for the (B) over tilde state. The theoretical lifetimes for the pure bending levels of the (A) over tilde and (B) over tilde states were calculated from the fluorescence decay rates for the (A) over tilde-(X) over tilde, (B) over tilde-(A) over tilde, and (B) over tilde-(X) over tilde emissions. (C) 2005 American Institute of Physics.
  • K Tokue, K Yamasaki, S Minamino, S Nanbu
    JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 4(1) 225-245 2005年3月  査読有り
    To elucidate the ionization dynamics, in particular the vibrational distribution, of H2O+((A) over tilde) produced by photoionization and the Penning ionization of H2O and D2O with He*(2 S-3) atoms, Franck-Condon factors (FCFs) were given for the H2O((X) over tilde) -> H2O+((X) over tilde,(A) over tilde) ionization, and the transition probabilities were presented for the H2O+ ((A) over tilde - (X) over tilde) emission. The FCFs were obtained by quantum vibrational calculations using the three-dimensional potential energy surfaces (PESs) of H2O((X) over tilde (1)(A) over tilde (1)) and H2O+ ((X) over tilde B-2(1), (A) over tilde (2)A(1)) electronic states. The global PESs were determined by the multi-reference configuration interaction calculations with the Davidson correction and the interpolant moving least squares method combined with the Shepard interpolation. The obtained FCFs exhibit that the H2O+ ((X) over tilde) state primarily populates the vibrational ground state, as its equilibrium geometry is almost equal to that of H2O((X) over tilde), while the bending mode (nu(2)) is strongly enhanced for the H2O+ ((A) over tilde) state; the maximums in the population of H2O+ and D2O+ are approximately nu(2) = 11-12 and 15-17, respectively. These results are consistent with the distributions observed by photoelectron spectroscopy. Transition probabilities for the (A) over tilde - (X) over tilde system of H2O+ and D2O+ show that the bending progressions consist primarily of the (A) over tilde - (X) over tilde emission, with combination bands from the (1, nu'(2) = 4-8, 0) level being next most important.
  • ZH Wang, T Urisu, H Watanabe, K Ooi, GR Rao, S Nanbu, J Maki, M Aoyagi
    SURFACE SCIENCE 575(3) 330-342 2005年2月  査読有り
    Infrared reflection absorption spectroscopy that used buried metal layer substrates (BML-IRRAS) and density functional cluster calculations were employed to investigate the water related oxidation reactions of 2H + H2O/ Si(100)-(2 x 1), 2D + H2O/Si(100)-(2 x 1), and H2O + H/Si(100)-(2 x 1). In addition to the oxygen inserted coupled monohydrides, which were previously reported in the former reaction system, we report several other oxidized Si hydride species in our BML-IRRAS experiments. Three new pairs of vibrational bands are identified between 900 and 1000 cm(-1). These vibrational frequencies were calculated using SO and Si10 cluster models that included all possible structures from zero to five oxygen insertions into the top layer silicon atoms using a B3LYP gradient corrected density functional method with a polarized 6-31G** basis set for all atoms. The three pairs of vibrational modes are assigned to the scissoring modes of adjacent and isolated SiH2 with zero, one, and two oxygen atoms inserted into the Si back bonds. All the other newly observed vibrational peaks related to Si oxidation are also assigned in this study. The Si-O stretching bands observed in the reaction 2D + H2O/Si(I 00)-(2 x 1) show an isotope effect, which suggests that in the system 2H + H20/Si(100)-(2 x 1) also, hydrogen atom tunneling plays an important role for the insertion of oxygen atoms into Si back bonds that form oxidized adjacent dihydrides. (C) 2004 Elsevier B.V. All rights reserved.

MISC

 9
  • 杉山数馬, 吉永竜平, 橋本剛, 南部伸孝, 早下隆士, 欅田英之, 江馬一弘
    応用物理学会春季学術講演会講演予稿集(CD-ROM) 67th 2020年  
  • 羽根田涼, 杉山数馬, 藤澤真友子, 欅田英之, 江馬一弘, 橋本剛, 早下隆士, 南部伸孝
    分子科学討論会講演プログラム&要旨(Web) 12th 2018年  
  • Toshimasa Ishida, Shinkoh Nanbu, Hiroki Nakamura
    INTERNATIONAL REVIEWS IN PHYSICAL CHEMISTRY 36(2) 229-285 2017年  査読有り招待有り
    It is now confirmed that the Zhu-Nakamura (ZN) theory of nonadiabatic transition is useful to investigate various nonadiabatic chemical dynamics. The theory, being one-dimensional, presents a whole set of analytical formulas that enables us to treat the dynamics efficiently. It is also quite significant that classically forbidden transitions can be dealt with analytically. The theory can be combined with the trajectory surface hopping (TSH) method (ZN-TSH) and is demonstrated to be useful to clarify the dynamics of not only simple tri-atomic reactions but also large chemical systems. The whole set of analytical formulas directly applicable to practical systems is summarised and the applications to polyatomic systems are illustrated. Examples of polyatomic molecules are H2SO4, NH3, indolylmaleimide, cyclohexadiene (CHD), and retinal. The Fortran code for the whole set of ZN formulas is provided in Appendix for the convenience of a reader who is interested in using them. The ZN-TSH method can be combined with the QM/MM method to clarify reaction dynamics in the surrounding environment. This is named as ZN-QM/MM-TSH. The particle-mesh Ewald (PME) method can also be combined with ZN-TSH to clarify reaction dynamics in solutions. This is named as ZN-PME-TSH. Formulations of these methods are presented together with practical applications. Examples treated by ZN-QM/MMTSH are photoisomerization dynamics of retinal chromophore embedded in the protein environment. The differences in the isomerization mechanisms between rhodopsin and isorhodopsin are made clear. The faster and more efficient isomerization of rhodopsin compared to isorhodopsin is nicely reproduced. Examples of reactions in solutions are photoisomerizations of retinal and CHD. The experimentally observed long life time of the excited state of retinal is reproduced and is found to be due to the long-range solvation effect. The solvent dependent branching ratios of CHD: hexatriene (HT) are clarified for the ethanol and hexane solvents by the ZN-PME-TSH method. Both ZN-QM/MM-TSH and ZN-PME-TSH are thus demonstrated to be promising methods to deal with a wide range of nonadiabatic dynamics in large chemical and biological systems.
  • 赤間 知子, 小林 理, 南部 伸孝, 武次 徹也
    ケモインフォマティクス討論会予稿集 2016 P10 2016年  
    時間依存Schrödinger方程式やその近似式は、実時間発展により超高速現象である電子ダイナミクスを記述できる。しかし、これらの時間微分方程式を解くための時間発展の計算は、高いコストを要することが多く、これまで適用が限られていた。一方、核波束ダイナミクスの分野では、Chebyshev多項式の3項間漸化式を用いて時間発展を行う実核波束発展法が開発され、計算コストの大幅な削減に成功している。そこで本研究では、実核波束発展法を参考に、効率的な時間発展法として3項間漸化式(3TRR)法を開発した。3TRR法では、演算子変換の導入によって導かれる3項間漸化式を用いて、変換されたエネルギー・時間軸上で効率的に計算を行う。元のエネルギーと時間を得るのに必要な逆変換の式の導出も行った。3TRR法を、電子ダイナミクスを記述するRT-TDHF/TDDFT計算に適用し、計算の効率化を目指した。
  • Shinkoh Nanbu, Toshimasa Ishida, Hiroki Nakamura
    CHEMICAL SCIENCE 1(6) 663-674 2010年  査読有り招待有り筆頭著者責任著者
    A variety of chemical phenomena are governed by non-adiabatic transitions at conical intersections of potential energy surfaces, if not directly, but indirectly in the midst of the processes. In other words, the non-adiabatic transition makes one of the most significant key mechanisms in chemical dynamics. Since the basic analytical theory is now available to treat the transitions, it is possible to comprehend the dynamics of realistic chemical and biological systems with the effects of transitions taken into account properly. Another important quantum mechanical effect of tunneling can also be taken into account. Furthermore, it becomes feasible to control chemical dynamics by controlling the non-adiabatic transitions at conical intersections, and also to develop new molecular functions by using peculiar properties of non-adiabatic transitions. These may be realized, if we apply appropriately designed laser fields. This perspective review article explains the above mentioned ideas based on the authors' recent activities. The non-adiabatic chemical dynamics is expected to open a new dimension of chemistry.
もっとみる

書籍等出版物

 14
もっとみる

講演・口頭発表等

 233
もっとみる

所属学協会

 6
もっとみる

共同研究・競争的資金等の研究課題

 33
もっとみる

社会貢献活動

 26
一覧へ戻る