Researchers Database

TAKASHIMA Hiroshi

FacultyFaculty Division of Natural Sciences Research Group of Chemistry
PositionAssociate Professor
Last Updated :2022/10/05

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Profile and Settings

  • Name (Japanese)

    Takashima
  • Name (Kana)

    Hiroshi

Degree

  • Ph. D., Kyushu University, Mar. 2000

Research Areas

  • Nanotechnology/Materials, Energy chemistry
  • Nanotechnology/Materials, Analytical chemistry
  • Nanotechnology/Materials, Inorganic and coordination chemistry
  • Nanotechnology/Materials, Biochemistry
  • Nanotechnology/Materials, Organic functional materials
  • Nanotechnology/Materials, Structural/physical organic chemistry

Research Experience

  • Oct. 2017, 9999, 奈良教育大学教育学部非常勤講師(兼任)
  • Apr. 2012, 9999, 奈良女子大学研究院自然科学系准教授
  • Apr. 2009, Mar. 2012, 奈良女子大学理学部化学科准教授
  • Oct. 2008, Dec. 2009, 奈良教育大学教育学部非常勤講師(兼任)
  • Apr. 2007, Mar. 2009, Assistant Professor
  • Apr. 2001, Mar. 2007, 奈良女子大学理学部化学科助手
  • Jun. 2000, Mar. 2001, 米国Yale大学分子生物物理化学科研究員
  • Apr. 2000, Mar. 2001, 日本学術振興会特別研究員(PD)
  • Jan. 1999, Mar. 2000, 日本学術振興会特別研究員(DC)

Education

  • 2000, Kyushu University, Graduate School, Division of Engineering, 物質創造工学
  • 1997, Doshisha University, Graduate School, Division of Engineering, 工業化学
  • 1995, Doshisha University, Faculty of Engineering, 工業化学

Association Memberships

  • 光化学協会
  • 錯体化学若手の会
  • 複合系の光機能研究会
  • 日本化学会生体機能関連化学部会
  • 錯体化学会
  • The Chemical Society of Japan
  • ホスト-ゲスト・超分子化学研究会, Jun. 2016, 9999

Ⅱ.研究活動実績

Published Papers

  • Refereed, Jan. 2022, 151, 131990
  • Refereed, Jan. 2022, 102, 133, 142
  • Refereed, May 2021, 1242, 130728
  • Refereed, 2021, 6, 100027
  • 2020, 19, 1, 16
  • Not Refereed, 教育システム研究, サイエンス・オープンラボを通した化学(化学発光、金属イオンの色)学習 −大学生による演示実験を動機付けにした高等学校授業開発研究−, Takayuki Nakajima; Yuji Mikata; Takashi Kajiwara; Takae Takeuchi; Yasuyuki Ura; Hiroshi Takashima; Noriyuki Matsuura, Mar. 2020, 15, 99, 109, Research institution
  • Refereed, ChemistrySelect, Anion Influence of Emission Properties and DFT Calculations of Diprotonated and Triprotonated Terpyridines, Naokazu Yoshikawa; Shoko Yamazaki; Natsumi Kato; Mika Sawai; Kaoru Noda; Nobuko Kanehisa; Eiji Nakata; Hiroshi Takashima, Dec. 2019, 4, 45, 13284, 13294, Scientific journal
  • Refereed, ChemistrySelect, Syntheses, X-ray crystal structures, emission properties and DFT calculations of monoprotonated polypyridines, Naokazu Yoshikawa; Shoko Yamazaki; Natsumi Kato; Akari Kubota; Mika Sawai; Kaoru Noda; Nobuko Kanehisa; Tsuyoshi Inoue; Eiji Nakata; Hiroshi Takashima, Jan. 2019, 4, 1, 59, 65
  • Refereed, Journal of Molecular Structure, Elsevier B.V., Study of the triplet excited states and DFT calculations of iridium(III) complexes with mixed ligands, Naokazu Yoshikawa; Shoko Yamazaki; Natsumi Kato; Nobuko Kanehisa; Tsuyoshi Inoue; Eiji Nakata; Hiroshi Takashima, Density functional theory (DFT) calculations were performed to examine the excited triplet states of various eight iridium(III) complexes and the relationship between these states and the emission spectra. The complexes investigated were 1 [Ir(NO3)2(phen)2]PF6, 2 [IrCl2(phen)2]PF6, 3 [Ir(NO2)2(dmbpy)2]PF6, 4 [IrCl2(dmbpy)2]PF6, 5 [IrCl2(tmphen)2]PF6, 6 [IrCl2(bqn)(dmbpy)]PF6, 7 [IrCl2(bqn)2]PF6 and 8 [IrCl2(bqn)(phen)]PF6. Here, phen is 1,10-phenanthroline, dmbpy is 4,4’-dimethyl-2,2’-bipyridine, tmphen is 3,4,6,7-tetramethyl-1,10-phenanthroline and bqn is 2,2’-biquinoline. Complexes 1, 3, 5, 6 and 8 were newly synthesized for this study and exhibited pronounced phosphorescent emission for 5, 6 and 8. All complexes were calculated to possess excited triplet states. The excited states of the complexes are primarily associated with metal-to-ligand charge transfer (MLCT) and π-π* transitions., 15 Jul. 2018, 1164, 164, 171, Scientific journal
  • Refereed, Journal of Physical Organic Chemistry, Photoinduced elecron-transfer reactions of tris(2,2’-bipyridine)ruthenium(II)-based carbonic anhydrase inhibitors tethering plural binding sites, Mikiko Suwa; Narumi Imamura; Pirika Awano; Eiji Nakata; Hiroshi Takashima, Apr. 2018, 31, 9, e3848
  • Refereed, Journal of Physical Organic Chemistry, John Wiley and Sons Ltd, Syntheses, X-ray crystal structures, and emission properties of protonated tripyridyltriazines and their ruthenium(II) complexes, Naokazu Yoshikawa; Shoko Yamazaki; Hiroko Kimura; Nobuko Kanehisa; Tsuyoshi Inoue; Hiroshi Takashima, A series of metal-free compounds, ie, planar triprotonated triazine, triazineH3Cl(PF6)2 (1), planar triprotonated triazineH3Br(PF6)2 (2), and nonplanar monoprotonated triazineHPF6 (3), were prepared. Abbreviations used are triazine = tri-2-pyridyltriazine. Ruthenium complexes [RuCl(bpy)(L)](PF6), [RuCl(bpy)(L)](PF6)2, and [Ru(L)2](PF6)2 were also prepared, where bpy is 2,2′-bipyridine and L's are triazine (4) and monoprotonated triazine (5), respectively. Ruthenium complexes [Ru(triazine)2](PF6)2 (6) were also prepared and crystallized. The X-ray crystal structures of the 3 compounds 1, 2, and 3 and the complex 6 were determined. They were also characterized by electrospray ionization mass spectrometry, UV-vis spectroscopy, and density functional theory calculations., 01 Mar. 2018, 31, 3, e3777, Scientific journal
  • Refereed, 化学と教育, 公益社団法人 日本化学会, 目で見て実感する化合物の分離・分析実験, TAKASHIMA Hiroshi,

    物質の分離精製には,カラムクロマトグラフィーが有効な手法となっている。講義だけでは理解しにくいカラムクロマトグラフィーの原理や技術について,生葉から抽出した光合成色素を用い,目で見て自分たちの手で分離精製することを実感できる実験を行った。

    , Apr. 2017, 65, 4, 184, 185
  • Refereed, JOURNAL OF MOLECULAR STRUCTURE, ELSEVIER SCIENCE BV, Emission property and DFT calculation for the (MLCT)-M-3 luminescence of Ru(bpy)(2)(L)(2+) complex, Naokazu Yoshikawa; Hiroko Kimura; Shinichi Yamabe; Nobuko Kanehisa; Tsuyoshi Inoue; Hiroshi Takashima, Electronic structures of ruthenium complexes [Ru(bpy)(2)(L)](2+) were studied by DFT calculations, where bpy is 2,2'-bipyridine and L's are its derivatives. They are parent (1) and five complexes with L = 4,4'dimethyl-2,2'-bipyridine (2), 6,6'-dimethy1-2,2'-bipyridine (3), biquinoline (4), 5-nitro-1,10phenanthroline (5) and two acetonitrile molecules (6). These complexes were characterized by ESIMS, 1H NMR, UV vis spectroscopy and elementary analysis. The crystal structures of 3.(PF6)2, 4.(PF6)2, 5.(PF6)2 and 6.(PF6)2 were also determined. Spin densities were analyzed to characterize the excited triplet states in those complexes. It was found that the complexes have three triplet (called here 3MLCT, 3MC1 and 3MC2) states. The 3MC1 and 3MC2 states have elongated Ru N bonds and large spin densities on Ru2. Those states are stable and would lead to the nonradiative relaxation to the ground state. In particular, those of 3, 5 and 6 are very stable, which results in their poor quantum yields (0 < 0.01) of the emissions. In contrast, both 1 and 2 showed the 3MLCT states. Energy gaps between triplet and ground states were compared with energies corresponding to wavelengths of emission spectra of 1-5. Good agreement between the calculated and the experimental energies was found. Moreover, dual emission which depends on the excitation wavelength was observed in complex 4. (C) 2016 Elsevier B.V. All rights reserved., Aug. 2016, 1117, 49, 56, Scientific journal
  • Refereed, JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, WILEY, Syntheses, X-ray crystal structures, and emission properties of diprotonated tetrapyridylpyrazine and triprotonated terpyridine, Naokazu Yoshikawa; Shinichi Yamabe; Nobuko Kanehisa; Tsuyoshi Inoue; Hiroshi Takashima, A series of metal-free compounds, that is, planar diprotonated tetraH(2)(PF6)(2) (1), planar monoprotonated bppzHPF(6) (2), nonplanar diprotonated bppzH(2)(PF6)(2) (3), and planar triprotonated terpyH(3)Cl(PF6)(2) (4), were prepared and characterized by electrospray ionization mass spectrometry, Ultraviolet-visible spectroscopy and cyclic voltammetry. Abbreviations used are tetra = tetra-2-pyridylpyrazine, bppz = 2,3-bis(2-pyridyl)pyrazine, and terpy = 2,2':6',2 ''-terpyridine. The X-ray crystal structures of the four compounds 1, 2, 3, and 4 were determined. Both protonated pyridine rings are hydrogen bonded intramolecularly to the adjacent pyridine ring in compounds 1 and 3. The pi-pi* absorption bands in the ultraviolet region for 1, 2, 3, and 4 in acetonitrile were red-shifted relative to those of the corresponding neutral unprotonated compounds. All the cyclic voltammetry for the protonated species, 1, 2, 3, and 4, showed the first reduction waves from -0.37 to -1.18 V, that were more positive than those of the neutral ones. Density functional theory was applied to interpret the planarity in 1. The attachment of two protons to the two terminal tetra nitrogens in 1 leads to the remarkable emission (Phi = 0.031). The attachment of three protons to the three terpy nitrogens in 4 also gives the large quantum yield (Phi = 0.48). Copyright (C) 2015 John Wiley & Sons, Ltd., Jun. 2016, 29, 6, 269, 275, Scientific journal
  • Refereed, JOURNAL OF MOLECULAR STRUCTURE, ELSEVIER SCIENCE BV, Transition states of the (MLCT)-M-3 to (MC)-M-3 conversion in Ru(bpy)(2)(phen derivative)(2+) complexes, Naokazu Yoshikawa; Shinichi Yamabe; Shigeyoshi Sakaki; Nobuko Kanehisa; Tsuyoshi Inoue; Hiroshi Takashima, Electronic structures of ruthenium complexes [Ru(bpy)(2)(L)](2+) were studied by DFT calculations, where bpy is 2,2'-bipyridine and L's are 1,10-phenanthroline (phen) derivatives. They are parent (1) and eight complexes with L = 4-phenyl-phen (2), 4,7-diphenyl-phen (3), 2,9-dimethyl-4,7-diphenyl-phen (4), 2, 9-dimethyl-phen (5), 3,4,7,8-tetramethyl-phen (6), 5-amino-phen (7), 5-methyl-phen (8), and 3-phenylethynyl-phen (9). Those complexes except 7, and 9 were prepared and characterized. Three triplet (called here (MLCT)-M-3, (MC1)-M-3 and (MC2)-M-3) states were obtained in all the complexes. (MC1)-M-3 and (MC2)-M-3 states were found to have the elongated Ru-N bonds and large spin densities on Ru2+. The geometry optimization of the triplet state of ruthenium complexes leads to the elongation of two trans Ru N bonds confirming the (MC)-M-3 character. The correlation between quantum yields and ((MLCT)-M-3 - (MC2)-M-3) energy gaps was examined and discussed. Successive conversion paths of ((MLCT)-M-3 -> (MC1)-M-3) and ((MC1)-M-3 -> (MC2)-M-3) of 1 and 5 were determined. Their activation energies were calculated to be very small. (C) 2015 Elsevier B.V. All rights reserved., Aug. 2015, 1094, 98, 108, Scientific journal
  • Refereed, Canadian Chemical Transactions, A DFT Study of the Triplet Excited States of Iridium(III) Complexes with Terpyridine Ligands, Naokazu Yoshikawa; Shinichi Yamabe; Shigeyoshi Sakaki; Nobuko Kanehisa; Tsuyoshi Inoue; Hiroshi Takashima, Jan. 2014, 2, 134, 148
  • Refereed, Journal of Physical Chemistry B, American Chemical Society, Photoinduced electron-transfer reactions of carbonic anhydrase inhibitor containing tris(2,2′-bipyridine)ruthenium(II) analogue, Hiroshi Takashima; Misa Fukuda; Fumie Nakagaki; Tomoko Ogata; Keiichi Tsukahara, A ruthenium(II) complex-based carbonic anhydrase (CA) inhibitor, [Ru(bpy)2(bpybs)]2+ {bpy = 2,2′-bipyridine and bpybs = 4′-methyl-2,2′-bipyridinyl-4-carboxylic acid (2-{2-[(4- sulphamoylbenzoylamino)ethoxy]ethoxy}ethyl)amide}, tethering a benzenesulfonamide group and a [Ru(bpy)3]2+ moiety has been prepared. The CA activity was effectively suppressed by a synthetic [Ru(bpy)2(bpybs)]2+ inhibitor, and the dissociation constant at pH 7.2 and at 25 C was determined to be KI = 1.9 ± 0.2 μM. Next, in the presence of CA and a sacrificial electron acceptor, such as pentaamminechlorocobalt(III) complex, the photoexcited triplet state of 3([Ru(bpy)2(bpybs)]2+)* was quenched through an intermolecular photoinduced ET mechanism to form the oxidized [Ru(bpy)2(bpybs)]3+, followed by the intramolecular electron abstraction from an amino-acid residue near the active site of CA. The resulting oxidized CA was catalytically inactive. Kinetic experiments also revealed that the second-order rate constant for the initial step and the first-order rate constant for the second step under our experimental conditions were kq = 4.8 × 107 M-1 s-1 and kIET = 6.6 × 104 s-1, respectively. Thus, the intramolecular ET between CA and [Ru(bpy)2(bpybs)] 3+ is a crucial event to regulate CA activity by the visible light irradiation of a synthetic [Ru(bpy)3]2+-type inhibitor. © 2013 American Chemical Society., 07 Mar. 2013, 117, 9, 2625, 2635, Scientific journal
  • Refereed, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, CHEMICAL SOC JAPAN, Differences of Structures and Electronic Properties in the Triplet States between Dibromo and Dichloro Mononuclear Polypyridine Iridium(III) Complexes, Naokazu Yoshikawa; Shinichi Yamabe; Nobuko Kanehisa; Tsuyoshi Inoue; Hiroshi Takashima; Keiichi Tsukahara, Emission and electronic properties of eight iridium(III)-centered polypyridine complexes were studied systematically. A crystal structure of [IrBr2(phen)(2)]PF6 was obtained by X-ray diffraction study, where phen is 1,10-phenanthroline. Those in the triplet states were also determined by DFT calculations to investigate the source of emission spectra. Two triplet structures of [IrX2(bpy)(2)](+) and [IrX2(bpy)(2)](+) and the transition state of interconversion were obtained with X- = Cl- and Br-. Here, bpy is 2,2'-bipyridine. For the chloro complexes, two triplet species have nonequivalent bpy and phen ligands through pseudo-Jahn-Teller geometric distortion. The dichloro complexes with asymmetric spin density distributions were found to correspond to stronger emission spectra than those for the dibromo compounds. Energies (E's) corresponding to the observed emission wavelengths (E-em's) are in good agreement with the theoretical S-0-T-1, energy differences (Delta E's). For [IrBr2(bpy)(2)](+), E-em = 2.29eV and Delta E= 2.26 eV. For [IrCl2(bpy)(2)](+), E-em = 2.29 eV and Delta E= 2.33 eV. For [IrBr2(phen)(2)](+), E-em = 2.26 eV and Delta E= 2.28 eV. For [IrCl2(bpy)(2)](+), E-em = 2.28 eV and Delta E= 2.34 eV. For all the four complexes, 1A, 1B, 3A, and 3B, DFT calculations indicate lr-N bond rupture. T-c with a small S-0-T-1 energy-gap would undergo nonradiative relaxation. T, indicates a triplet state which is a five-coordinate species with triplet metal-centered character. Coexistence of the triplet state species are discussed in terms of their electronic structures., Dec. 2011, 84, 12, 1347, 1354, Scientific journal
  • Refereed, JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, WILEY-BLACKWELL, The key Cl- ligand for metal-to-ligand charge transfer in mononuclear terpyridine ruthenium(II) and binuclear ruthenium(II) tetrapyridylpyrazine complexes, N. Yoshikawa; S. Yamabe; N. Kanehisa; T. Inoue; H. Takashima; K. Tsukahara, Electronic structures of binuclear ruthenium complexes [Ru-2(terpy)(2)(tppz)](4+) (1A) and [Ru2Cl2(L)(2)(tppz)](2+) {L = bpy (2A), phen (3A), and dpphen (4A)} were studied by density functional theory calculations. Abbreviations of the ligands (Ls) are bpy = 2,2'-bipyridine, phen = 1,10-phenanthroline, dpphen = 4,7-diphenyl-1,10-phenanthroline, terpy = 2,2':6',2(n)-terpyridine, and tppz = tetrakis(2-pyridyl)pyrazine. Their mononuclear reference complexes [Ru(terpy)(2)](2+) (1B) and [RuClL(terpy)](+) {L = bpy (2B), phen (3B), and dpphen (4B)} were also examined. Geometries of these mononuclear and binuclear Ru(II) complexes were fully optimized. Their geometric parameters are in good agreement with the experimental data. The binuclear complexes were characterized by electrospray ionization mass spectrometry, UV-Vis spectroscopy, and cyclic voltammograms. Hexafluorophosphate salts of binuclear ruthenium complexes of 3A and 4A were newly prepared. The crystal structure of binuclear complex 1A(PF6)(4) was also determined. Orbital interactions were analyzed to characterize the metal-to-ligand charge-transfer (MLCT) states in these complexes. The Cl- ligand works to raise the orbital energy of the metal lone pair, which leads to the low MLCT state. Copyright (C) 2011 John Wiley & Sons, Ltd., Nov. 2011, 24, 11, 1110, 1118, Scientific journal
  • Refereed, JOURNAL OF PHYSICAL CHEMISTRY B, AMER CHEMICAL SOC, Photophysical and DNA-Binding Properties of Cytochrome c Modified with a Platinum(II) Complex, Hiroshi Takashima; Miho Kitano; Chiharu Hirai; Hiroshi Murakami; Keiichi Tsukahara, Cytochrome c (cyt c) derivatives modified with a platinum(II) complex at the lysine residue, cyt c(III)-[Pt(bpy)(dapap)](1) {bpy = 2,2'-bipyridine, and dapap = 3-(2,3-diaminopropionylamino)propionic acid}, have been prepared. The modified residues are Lys8, Lys13, Lys55, Lys60, Lys73, and Lys88. In the case of the cyt c(III)-[Pt(bpy)(dapap)](1) dyad, the photoexcited singlet state of (1)([Pt(bpy)(dapap)](1))* was quenched by the heme Fe(III) moiety through the intramolecular photoinduced energy-transfer reaction via a through-space mechanism. Next, in the presence of calf thymus (CT)-DNA, the DNA-responsive fluorescence properties of cyt c(III)-(Pt(bpy)(dapap)](1) isomers were investigated. The order of the obtained binding constants between the cyt c(III)-[Pt(bpy)(dapap)](1) isomer and CT-DNA in an aqueous solution suggested that the electrostatic interaction is one of the important factors to stabilize the cyt c-DNA complex. Finally, we discussed the rotational motion of the [Pt(bpy)(dapap)](2+) moiety at the surface of cyt c by fluorescence anisotropy measurement. The increase in the anisotropy parameter, r, for each cyt c isomer clearly revealed that the noncovalent recognition of the [Pt(bpy)(dapap)](2+) moiety by CT-DNA is an essential event in the formation of the cyt c-DNA complex and generation of DNA-sensitive fluorescence signals., Nov. 2010, 114, 43, 13889, 13896, Scientific journal
  • Refereed, JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, JOHN WILEY & SONS LTD, Remarkable emissions in diprotonated 2,2 ':6 ',2 ''-terpyridine derivatives, Naokazu Yoshikawa; Shinichi Yamabe; Nobuko Kanehisa; Tsuyoshi Inoue; Hiroshi Takashima; Keiichi Tsukahara, A series of new metal-free blue emission compounds, i.e., diprotonated terpyH(2)CIPF(6) (1), tterpyH(2)CIPF(6) (2), ClterpyH(2)CIPF(6) (3), and BterpyH(2)(PF(6))(2) (4), were prepared and characterized by electrospray ionization mass spectrometry, UV-vis spectroscopy, and cyclic voltammetry (CV). Abbreviations used are terpy = 2,2':6',2 ''-terpyridine, tterpy = 4'-(4-tolyl)-2,2':6',2 ''-terpyridine, Clterpy = 4'-chloro-2,2':6',2 ''-terpyridine, and Bterpy = 4,4',4 ''-tert-butyl-2,2':6',2 ''-terpyridine. The X-ray crystal structures of the three new compounds 1, 2, and 4 were determined. Both protonated pyridine rings of the terpyridine derivatives are hydrogen bonded intermolecularly to the adjacent Cl(-) ion in compounds 1, 2, and 3. The pi-pi* absorption bands in the UV region for 1, 2, 3, and 4 in acetonitrile were red-shifted relative to those of the corresponding neutral compounds. All the compounds exhibited stronger emissions (around 400 nm) than their neutral counterparts. All the CVs for the diprotonated species, terpyH(2)(2+), tterpyH(2)(2+), ClterpyH(2)(2+), and BterpyH(2)(2+), showed the first reduction waves around -0.6 V, which were more positive than those of the neutral ones. Density functional theory was applied to interpret the remarkable differences in the interaction of the Cl(-) ion. The attachment of two protons to the two terminal Bterpy nitrogens in 4 elicits remarkable characteristics. Both positive charges on the nitrogens are delocalized over the conjugated pyridine systems and the tertiary carbonium ions are stabilized to lead to stronger emission (Phi = 0.35) than the corresponding neutral Bterpy (Phi = 0.045). CCDC 732045-732047 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif Copyright (C) 2010 John Wiley & Sons, Ltd., May 2010, 23, 5, 431, 439, Scientific journal
  • Refereed, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, CHEMICAL SOC JAPAN, Direct Comparison of Chiral Substituent Effects for Viologens in Stereoselective Photoinduced Electron-Transfer Reactions with Zinc Myoglobin, Hiroshi Takashima; Satomi Shibata; Yuka Sekiguchi; Yoshitane Imai; Keiichi Tsukahara, In order to understand the detailed mechanisms of stereoselective photoinduced electron-transfer (ET) reactions of zinc-substituted myoglobin (ZnMb) with optically active viologens by flash photolysis, we prepared new optically active agents, such as (R,R)- and (S,S)-1,1'-bis(3-hydroxy-2-methylpropyl)-4,4'-bipyridinediylium dichloride ([BMV]Cl-2). The photo-excited triplet state of ZnMb, (3)(ZnMb)*, was successfully quenched by (R,R)- and (SS)-[BMV](2+) ions to form the radical pair of ZnMb cation (ZnMb(center dot+)) and (R,R)- and (S,S)-[BMV](center dot+), followed by a thermal back ET reaction to the ground state. The ratio of the rate constants (k(q)) for ET quenching at 25 degrees C, k(q)(R,R)/k(q)(S,S) = 1.1, indicates that the (R,R)-[BMV](2+) preferentially quenches (3)(ZnMb)*. The selectivity of the rate constants (k(b)) for the back ET from (R,R)- and (SS)-[BMV](center dot+) to ZnMb(center dot+) at 25 degrees C was k(b)(R,R)/k(b)(S,S) = 0.83. The highest stereoselectivity of 1.3 for [BMV](center dot+) was found at low temperature (10 degrees C) in the thermal back ET reaction, where Delta Delta H not equal(R-S) = 6.2 +/- 1.9 kJ mol(-1) and Delta Delta S not equal(R-S) = 19 +/- 2 J mol(-1) K-1 were obtained. The structural differences between [BMV](2+) and the other viologens imply that the bulky aromatic substituent seems to be more important than the distance from the chiral center to the viologen moiety in order to enhance the ET stereoselectivity., Oct. 2009, 82, 10, 1250, 1257, Scientific journal
  • Refereed, JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, JOHN WILEY & SONS LTD, A metal free blue emission by the protonated 2,2 ':6 ',2 ''-terpyridine hexafluorophosphate, Naokazu Yoshikawa; Shinichi Yamabe; Nobuko Kanehisa; Hiroshi Takashima; Keiichi Tsukahara, Mono-protonated 2,2':6',2 ''-terpyridine (terpy) compound, 2,2':6',2 ''-terpyridinium hexafluorophosphate {[terpyH]PF(6)}, was prepared and characterized by electrospray ionization mass spectrometry, UV-Vis and emission spectroscopies, cyclic voltammogram (CV), and X-ray crystallography. The proton is located at the central pyridine nitrogen atom of terpy and was found in electron density difference map, which is completely different from the previously reported mono-protonated species, such as [terpyH]ReO(4) and [terpyH]CF(3)SO(3). The H(+) in the latter species is located at the terminal pyridine nitrogen. A small difference of proton positions was found to give a drastic difference of crystal patterns. For [terpyH]PF(6) in CH(3)CN, a new pi-pi* band in the UV region and a blue emission (Phi = 0.052 at room temperature) appeared whose maxima were red-shifted relative to those of the corresponding neutral terpy ligand. CV for the proton adduct showed the first reduction wave at around -0.6 V, being more positive than that of the neutral species. Finally, the density-functional theory (DFT) approach was used to investigate isomerization processes of the protonated terpy. Copyright (C) 2008 John Wiley & Sons, Ltd., May 2009, 22, 5, 410, 417, Scientific journal
  • Refereed, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, WILEY-V C H VERLAG GMBH, Detailed Description of the Metal-to-Ligand Charge-Transfer State in Monoterpyridine Ir-III Complexes, Naokazu Yoshikawa; Shinichi Yamabe; Nobuko Kanehisa; Tsuyoshi Inoue; Hiroshi Takashima; Keiichi Tsukahara, We synthesized four Ir-III terpyridine complexes with three Cl- anions by using microwave irradiation. By introducing three Cl- anions to the Ir3+ cation, it can be expected that the absorption and emission properties of the complexes change from pi-pi* to metal-to-ligand charge transfer (MLCT). These complexes having intrinsic C-2v symmetry are suitable for analyzing orbital interactions. This symmetry has four irreducible representations, a(1), a(2), b(1), and b(2), which results in no degenerate orbitals. Charge transfers (CTs) from three nitrogen lone-pair orbitals to the 5d(z2) and 5d(x2-y2) atomic orbitals give three Ir-N coordination bonds in the in-plane molecular orbital (MO) overlap of a(1) symmetry. These CTs are described by the 60th and 66th MOs in the [IrCl3(terpy)] complex, (terpy = 2,2':6',2 ''-terpyridine). The antibonding combination of the 5d(xz) and the lone-pair orbital of Cl- gives rise to the high-lying HOMO in b(1) symmetry. The back CT, the highest occupied molecular orbital (HOMO) (b(1)) -> the lowest unoccupied molecular orbital (LUMO) (b(1)), corresponds to MLCT, and the small-energy excitation is confirmed by the long wavelength lambda(max) approximate to 500 nm in the absorption spectroscopy. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009), May 2009, 14, 14, 2067, 2073, Scientific journal
  • Refereed, INORGANICA CHIMICA ACTA, ELSEVIER SCIENCE SA, Structures of polypyridine mononuclear Ir-III complexes in the ground state and the lowest triplet state, Naokazu Yoshikawa; Shinichi Yamabe; Nobuko Kanehisa; Yasushi Kai; Hiroshi Takashima; Keiichi Tsukahara, The structures of eight Ir-III centered polypyridine complexes were determined by density-functional-theory calculations. The differences in the optimized geometries between the ground state and the lowest excited triplet state were mainly considered. A crystal structure of [IrCl(bpy)(terpy)](PF6)(2) was also obtained by the X-ray diffraction study, where bpy is 2,2'-bipyridine and terpy is 2,2':6',2 ''-terpyridine. The computed geometries are in good agreement with the experimental ones. Those in the triplet biradical states were determined to evaluate the energy difference between the triplet and the ground states. The resulted values correlate well with the observed emission energies. To investigate the nature of the electronic transition involving the ground and the. first excited triplet states, a Mulliken population analysis of the spin densities on the eight complexes was performed. The geometric changes from free tterpy ligand {tterpy = 4'-(4-tolyl)-2,2':6',2 ''-terpyridine} to the IrIII complexed ligand, and then to triplet biradical were examined. The planarity enhanced the pi-pi* excitation in the ligand and consequently gave the stable triplet biradical of the complex. It was found that efficient phosphorescence should be impacted by the presence of one coplanar polypyridine ligand. (C) 2008 Elsevier B.V. All rights reserved., Jan. 2009, 362, 2, 361, 371, Scientific journal
  • Refereed, JOURNAL OF PHYSICAL CHEMISTRY B, AMER CHEMICAL SOC, Metal Ion-Dependent Fluorescent Dynamics of Photoexcited Zinc-Porphyrin and Zinc-Myoglobin Modified with Ethylenediaminetetraacetic Acid, Hiroshi Takashima; Hiroe Kawahara; Miho Kitano; Satomi Shibata; Hiroshi Murakami; Keiichi Tsukahara, The reconstituted zinc - myoglobin (ZnMb) dyads, ZnMb-[M(II)(edta)], have been prepared by incorporating a zinc-porphyrin (ZnP) cofactor modified with ethylenediaminetetraacetic acid (H(4)edta) into apo-Mb. In case of the monomeric ZnP(edta) cofactor coordinated by one pyridine molecule, ZnP(py)(edta), a spontaneous 1: 1 complex with a transient metal ion was formed in an aqueous solvent, and the photoexcited singlet state of ZnP, (1)(ZnP)*, was quenched by the [Cu(II)(edta)] moiety through intramolecular photoinduced electrontransfer (ET) reaction. The rate constant for the intramolecular quenching ET (k(q)) at 25 degrees C was successfully obtained as k(q) = 5.1 x 10(9) s(-1). In the case of Co(2+), Ni(2+), and Mn(2+), intersystem crossing by paramagnetic effect was mainly considered between (1)(ZnP)* and the [M(II)(edta)] complex. For the ZnMb-[M(II)(edta)] systems, the intramolecular ET reaction between the excited singlet state of (I)(ZnMb)* and the [Cu(II)(edta)] moieties provided the slower quenching rate constant, k(q) = 2.1 x 10(8) s(-1), compared with that of the ZnP(py)(edta) one. Kinetic studies also presented the efficient fluorescence quenching of the (1)(ZnMb)*-[Co(II)(edta)] dyad. Our study clearly demonstrates that wrapping of the ZnP cofactor by the apoprotein matrix and synthetic manipulation at the Mb surface ensure metal ion-sensitive fluorescent dynamics of ZnMb and provides valuable information to elucidate the complicated mechanism of the biological photoinduced ET reactions of hemoproteins., Dec. 2008, 112, 48, 15493, 15502, Scientific journal
  • Refereed, JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY, SPRINGER, Synthesis and photophysical properties of zinc myoglobin appending an ethidium ion as a DNA intercalator, Hiroshi Takashima; Yukiko Matsushima; Yasuyuki Araki; Osamu Ito; Keiichi Tsukahara, In order to elucidate the intramolecular photoinduced electron-transfer or energy-transfer mechanisms of the zinc myoglobin (ZnMb) dyad and to construct a photoreaction system within a Mb-DNA complex, we newly prepared ZnMb appending an ethidium ion (Et+). The steady-state fluorescence of ZnMb-Et+ at 600 nm and its lifetime (2.2 ns) indicate that the excited singlet state of (1)(ZnMb)* is not quenched by the Et+ moiety, whereas the lifetime of the excited triplet state of (3)(ZnMb)*-Et+ was shorter (tau = 4.3 ms) than those of ZnMb and the intermolecular (ZnMb + ethidium) system. Upon photoirradiation of Et+, fluorescence studies indicated the intramolecular quenching reactions from the excited singlet state, (1)(Et+)*, to ZnMb, the process of which is likely the photoinduced energy-transfer reaction via a through-space mechanism. We also demonstrate the photophysical and spectroscopic properties of ZnMb-Et+ in the presence of calf thymus (CT) DNA. The changes in the absorption and fluorescence spectra of ZnMb-Et+ on the addition of CT-DNA up to 15 equiv were very small, indicating that there are no major changes in the heme pocket. However, we observed a longer lifetime of (3)(ZnMb)*-Et+ in the presence of CT-DNA (tau = 5.3 ms) by single flash photolysis. This was induced by noncovalent interactions between Et+ and CT-DNA, followed by a conformational change of Et+ at the surface of ZnMb, where the donor-acceptor distance was probably elongated by CT-DNA. The synthetic manipulation at the Mb surface, by using a DNA intercalator coupled with photoinduced reaction, may provide a sensitive transient signal for DNA and valuable information to construct new Mb-DNA complex., Feb. 2008, 13, 2, 171, 181, Scientific journal
  • Refereed, CHEMISTRY & BIODIVERSITY, WILEY-V C H VERLAG GMBH, Synthesis and Spectroscopic Properties of Reconstituted Zinc-Myoglobin Appending a DNA-Binding Platinum(II) Complex, Hiroshi Takashima; Emi Fujimoto; Chiharu Hirai; Keiichi Tsukahara, A reconstituted zinc-myoglobin (ZnMb) dyad, ZnMb-[Pt(bpy)(en)](2+), has been prepared by incorporating chemically-modified zinc-porphyrin, being capable of DNA-binding of the Pt complex, [Pt(bpy)(en)](2+), where bpy and en are 2,2'-bipyridine and ethylenediamine, respectively. The steady-state fluorescence of the cofactor, [Pt(bpy)(mu-enPP)Zn]Cl-2, in MeOH indicates that the excited singlet state of zinc-porphyrin was almost quenched, probably because of the strong hydrophobic and pi-pi stacking interactions between the [Pt(bpy)(mu-enPP)Zn](2+) ions. In the reconstituted ZnMb[Pt(bpy)(en)](2+), the quenching reaction of (1)(ZnMb)* with the [Pt(bpy)(en)](2+) moiety does not occur, indicating apo-Mb matrix is essential. On the other hand, when the [Pt(bpy)(en)](2+) moiety was excited, the enhancement of the fluorescence from ZnMb unit was observed. It is suggested that the energy transfer from (1)([Pt(bpy)(en)](2+))* to ZnMb occurs. The spectroscopic changes of ZnMb-[Pt(bpy)(en)](2+) in the presence of calf-thymus DNA were also provided. Soret band at 428 nm gradually decreased, and isosbestic points at 321, 414, and 432 nm were observed with increasing the DNA concentration. When the Pt-II moiety was excited at lambda(ex) 321 nm, the fluorescence signal around 600 nm similarly decreased. The synthetic manipulation of ZnMb by using a DNA-binding Pt-II complex demonstrates sensitive fluorescent signal for DNA and valuable information to study photoinduced electron transfer within a Mb-DNA complex., 2008, 5, 10, 2101, 2112, Scientific journal
  • Not Refereed, 第8回光量子科学研究シンポジウム論文集, エチレンジアミン四酢酸を修飾した亜鉛ミオグロビンの光ダイナミックス, TAKASHIMA Hiroshi, 2008, 69-72
  • Refereed, EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, WILEY-V C H VERLAG GMBH, Synthesis, characterization, and DFT investigation of Ir-III tolylterpyridine complexes, Naokazu Yoshikawa; Shinichi Yamabe; Nobuko Kanehisa; Yasushi Kai; Hiroshi Takashima; Keiichi Tsukahara, Three new polypyridine iridium(III) complexes [(IrCl)-Cl-III(L)-(tterpy)](PF6)(2) (L = phen (1), dpphen (2), and dmbpy (3)) were prepared. Reference complexes [(IrCl)-Cl-III(bpy)(tterpy)](PF6)(2) (4) and [Ir-III(L)(2)](PF6)(3) (L = tterpy (5) and terpy (6)) were also prepared. Abbreviations of the ligands used here are phen = 1,10-phenanthroline, dpphen = 4,7-diphenyl-1,10-phenanthroline, bpy = 2,2'-bipyridine, dmbpy = 4,4'-dimethyl-2,2'-bipyridine, tterpy = 4'-(4-tolyl)-2,2':6',2"-terpyridine, and terpy = 2,2':6',2"-terpyridine. The syntheses, which were accomplished in typical reaction times of fifteen minutes by using a microwave oven, were easier than a previous method. The complexes were characterized by electrospray mass spectrometry, UV/Vis spectroscopy, and cyclic voltammetry (CV). The X-ray structures of the two complexes 5 and 6 were also obtained. Cyclic voltammograms of all the [(IrCl)-Cl-III(L)(tterpy)](2+) complexes showed that the first reduction occurred at around -0.67 V, which is attributed to the reduction of the tterpy ligand in [(IrCl)-Cl-III(L)(tterpy)](2+). The electronic properties of complexes 5 and 6 were studied by using B3LYP functional calculations, and their optimized geometries were compared to those of the experimentally observed ones. Excited triplet and singlet states are also examined by using time-dependent density functional theory (TDDFT). The calculated energies of the lowest singlet and triplet states in the two complexes are in good agreement with the experimental absorption and phosphorescence spectra. In this study, it was found that [(IrCl)-Cl-III(L)(tterpy)](2+) emits an intense phosphorescence at room temperature. Since the lowest unoccupied molecular orbitals (LUMOs) of all [(IrCl)-Cl-III(L)-(tterpy)](2+) complexes are composed of the pi*-system contribution of the tterpy ligand, the spectroscopic and electrochemical results are discussed comparatively, ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)., May 2007, 13, 13, 1911, 1919, Scientific journal
  • Refereed, JOURNAL OF PHYSICAL CHEMISTRY B, AMER CHEMICAL SOC, Photoinduced intramolecular electron-transfer reactions of reconstituted met- and zinc-myoglobins appending acridine and methylacridinium ion as DNA-binders, Hiroshi Takashima; Chisako Tara; Sachiko Namikawa; Tomoko Kato; Yasuyuki Araki; Osamu Ito; Keiichi Tsukahara, Three types of reconstituted met- and zinc-myoglobin (metMb and ZnMb) dyads, ZnMbAc(4)Me+, ZnMbAc(6)Me+, and metMbAc(6) have been prepared by incorporating chemically modified metalloporphyrin cofactor appending an acridine (Ac) or a methylacridinium ion ([AcMe](+)) into apo-Mb. In the bimolecular system between ZnMb and [AcMe](+), the photoexcited triplet state of ZnMb, (3)(ZnMb)*, was successfully quenched by [AcMe](+) to form the radical pair of ZnMb cation (ZnMb(center dot+)) and reduced methylacridine ([AcMe](center dot)), followed by a thermal back ET reaction. The rate constants for the intermolecular quenching ET (k(q)) and the back ET reaction (k(b)) at 25 degrees C were successfully obtained as k(q) = (8.8 +/- 0.4) x 10(7) M-1 s(-1) and k(b) = (1.2 +/- 0.1) x 10(8) M-1 s(-1), respectively. On the other hand, in case of the intramolecular photoinduced ET reactions of ZnMbAc(4)Me+ and ZnMbAc(6)Me+ dyads, the first-order quenching rate constants (k(ET)) of (3)(ZnMb)* by [AcMe](+) moiety were determined to be k(ET) = 2.6 x 10(3) and 2.5 x 10(3) s(-1), respectively. When such ET occurs along the alkyl spacer via through-bond mechanism at the surface of Mb, the obtained k(ET) is reasonable to provide decay constant of beta (1.0-1.3 A(-1)). Upon photoirradiation of [AcMe](+) moiety, kinetic studies also presented the intramolecular quenching reactions from the excited singlet state, (1)([AcMe](+))*, whose likely process is the photoinduced energy-transfer reaction. For metMbAc(6) dyad, steady-state fluorescence was almost quenched, while the signal around 440 nm gradually appeared in the presence of various concentrations of DNA. Our study implies that synthetic manipulation at the Mb surface, by using an artificial DNA-binder coupled with photoinduced reaction, may provide valuable information to construct new Mb-DNA complex and sensitive fluorescent for DNA., Dec. 2006, 110, 51, 26413, 26423
  • Refereed, INORGANICA CHIMICA ACTA, ELSEVIER SCIENCE SA, Syntheses, characterization, and DFT investigation of new mononuclear acetonitrile- and chloro-ruthenium(II) terpyridine complexes, Naokazu Yoshikawa; Shinichi Yamabe; Nobuko Kanehisa; Yasushi Kai; Hiroshi Takashima; Keiichi Tsukahara, A series of mononuclear acetonitrile complexes of the type [Ru(CH3CN)(L)(terpy)](2+) {L = phen (1), dpbpy (3), and bpm (5)}, and their reference complexes [RuCl(L)(terpy)](+) {L = phen (2), dpbpy (4), and dpphen (6)} were prepared and characterized by electrospray ionization mass spectrometry, U-V-vis spectroscopy, and cyclic voltammograms (CV). Abbreviations of the ligands (Ls) are phen = 1,10-phenanthroline, dpbpy=4,4'-diphenyl-2,2'-bipyridine, bpm=2,2'-bipyrimidine, dpphen=4,7-diphenyl-1,10-phenanthroline, bpy= 2,2'-bipyridine, and terpy=2,2':6',2"-terpyridine. The X-ray structures of the two complexes 2 and 3 were newly obtained. The metal-to-ligand charge transfer (MLCT) bands in the visible region for 1, 3, and 5 in acetonitrile were blue shifted relative to those of the reference complexes [RuCl(L)(terpy)](+). CV for all the [Ru(CH3CN)(L)(terpy)](2+) complexes showed the first oxidation wave at around 0.95 V, being more positive than those of [RuCI(L)(terpy)](+). The time-dependent-density-functional-theory approach (TDDFT) was used to interpret the absorption spectra of 1 and 2. Good agreement between computed and experimental absorption spectra was obtained. The DFT approach also revealed the orbital interactions between Ru(phen)(terpy) and CH3CN or Cl-. It is demonstrated that the HOMO-LUMO energy gap of the acetonitrile ligand is larger than that of the Cl- one. (c) 2006 Elsevier B.V. All rights reserved., Nov. 2006, 359, 14, 4585, 4593, Scientific journal
  • Refereed, INORGANICA CHIMICA ACTA, ELSEVIER SCIENCE SA, Syntheses, structures, and mesomorphic properties of two series of oxovanadium(IV) salen and salpn complexes with 4-substituted long alkoxy chains, Yuriko Abe; Kyoko Nakabayashi; Nahoko Matsukawa; Hiroshi Takashima; Masayasu Iida; Tomoaki Tanase; Makiko Sugibayashi; Hidetomo Mukai; Kazuchika Ohta, Two series of oxovanadium(IV) salen and salpn complexes containing 4-substituted alkoxy chains of aromatic rings, [VO((4-CnH2n+1O)(2)salen)] (n = 3 (1), 4 (2), 6 (3), 8 (4), 10 (5), 12 (6), 14 (7), 16 (8), 18 (9), and 20 (10) and salen = N,N'-ethylenebis(salicylideneiminato)), and [VO((4-CnH2n+1O)(2)salpn)] (n = 8 (11), 10 (12), 12 (13), 14 (14), 16 (15), and 18 (16) and salpn = N,N'-propylenebis(salicylideneiminato)), have been prepared and their mesomorphic properties have been investigated. The crystal structures of 1-9 except for 7 by an X-ray crystallographic analysis have been revealed. Complexes 4-9 in the solid state have been confirmed as novel bilayer crystal structures composed of only the VO(IV) complex without linear chains via the V=O units. The VO(IV) complexes with longer alkoxy chains of 8-10 transferred from the bilayer crystal to the bilayer metallomesogens (liquid crystals). Based on the X-ray analyses and the precise extinction rules for 8-10 with the bilayer metallomesogens, complexes 8-10 were identified as the liquid crystalline (M(Pa2(1))) phase derived from 80 layer groups, On the other hand, the 4-alkoxysalpn complexes of 14-16 showed the unusual rectangular columnar mesophase (Col(Gamma)) with the linear chain via the V=O units supported by the existence of the V=O stretching band characteristic of weak linear chain formation via the V=O units in the liquid crystal. (c) 2006 Elsevier B.V. All rights reserved., Sep. 2006, 359, 12, 3934, 3946, Scientific journal
  • Refereed, INORGANICA CHIMICA ACTA, ELSEVIER SCIENCE SA, Syntheses, structures, and mesomorphism of a series of Ni(II) salen complexes with 4-substituted long alkoxy chains, Yuriko Abe; Hiroko Akao; Yukiko Yoshida; Hiroshi Takashima; Tomoaki Tanase; Hidetomo Mukai; Kazuchika Ohta, A series of nickel(II) salen complexes containing 4-substituted alkoxy chains of aromatic rings, [Ni((4-CnH2n+1O)(2)salen)] (n = 3 (1), 4 (2), 6 (3), 8 (4), 10 (5), 12 (6), 14 (7), 16 (8), 18 (9), and 20 (10)), and their parent complex, [Ni((4-HO)(2)salen)] (11) (salen = N,N'-ethylenebis(salicylideneiminato)), have been prepared and mesomorphic properties have been investigated. An X-ray crystallographic analysis revealed that complex 11 (.) 2DMF has one-dimensional stacking structure supported by the pi-pi interaction between the six-membered chelate and aromatic rings with the Ni-Ni distances of alternatively 3.3957 and 3.7224 angstrom and that complex 3 is formed by one-dimensional stacking by weak C-H center dot center dot center dot 0 type hydrogen bonded interaction between the five-membered chelate ring and phenoxo atoms of the dramatically distorted salen moieties with the Ni-Ni distance of 5.994 angstrom. Complexes 1-6 did not exhibit any mesophases. On the other hand, complexes 7-10 with longer alkoxy chains of n = 14-20 showed an unusual metallomesogen of a lamello-columnar mesophase within the smectic layers with an interlamellar distance of 31.1 angstrom (7), 33.6 angstrom (8), 37.1 angstrom (9), and 39.5 angstrom (10) and nearly constant stacking distance of 6.19-6.24 angstrom between the inter-dimers, irrespective of the variation of the alkoxy chain lengths by the X-ray diffraction measurements of the liquid crystal. The relationship between molecular assemblies and mesomorphic properties is discussed. (c) 2006 Elsevier B.V. All rights reserved., Jul. 2006, 359, 10, 3147, 3155, Scientific journal
  • Refereed, JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY, SPRINGER, Stereoselective and driving-force-dependent photoinduced electron-transfer reactions of zinc myoglobin with optically active N,N '-dimethylcinchoninium and N,N '-dimethylcinchonidinium ions, H Takashima; A Araki; K Takemoto; N Yoshikawa; K Tsukahara, In order to understand the detailed mechanism of the stereoselective photoinduced electron-transfer (ET) reactions of zinc-substituted myoglobin (ZnMb) with optically active molecules by. ash photolysis, we designed and prepared new optically active agents, such as N,N'-dimethylcinchoninium diiodide ([MCN] I-2) and N,N'-dimethylcinchonidinium diiodide ([MCD] I-2). The photoexcited triplet state of ZnMb, (3)(ZnMb)*, was successfully quenched by [MCN](2+) and [MCD](2+) ions to form the radical pair of ZnMb cation (ZnMb(+)) and reduced [MCN](+) and [MCD](+), followed by a thermal back ET reaction to the ground state. The rate constants (k(q)) for the ET quenching at 25 degrees C were obtained as k(q)(MCN)=( 1.9 +/- 0.1) x 10(6) M-1 s(-1) and k(q)(MCD) = (3.0 +/- 0.2) x 10(6) M-1 s(-1), respectively. The ratio of k(q)(MCD)/ k(q)(MCN)= 1.6 indicates that the [MCD](2+) preferentially quenches (3)(ZnMb)*. The second-order rate constants (k(b)) for the thermal back ET reaction from [MCN](+) and [MCD](+) to ZnMb + at 25 degrees C were k(b)(MCN)=(0.79 +/- 0.04) x 10(8) M-1 s(-1) and k(b)(MCD)= (1.0 +/- 0.1) x 10(8) M-1 s(-1), respectively, and the selectivity was k(q)(MCD)/ k(q)(MCN)= 1.3. Both quenching and thermal back ET reactions are controlled by the ET step. In the quenching reaction, the energy differences of Delta Delta H not equal (MCD - MCN) and Delta Delta S-not equal (MCD - MCN) at 25 degrees C were obtained as - 1.1 and 0 kJ mol(-1), respectively. On the other hand, Delta Delta H-not equal (MCD - MCN)= 11 +/- 2 kJ mol(-1) and T Delta Delta S-not equal (MCD - MCN)= - 10 +/- 2 kJ mol(-1) were given in the thermal back ET reaction. The highest stereoselectivity of 1.7 for [MCD](+) found at low temperature (10 degrees C) was due to the Delta Delta S-not equal value obtained in the thermal back ET reaction., Apr. 2006, 11, 3, 316, 324, Scientific journal
  • Refereed, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, CHEMICAL SOC JAPAN, Selective and monofunctional guanosine 5 '-monophosphate binding by chloro[3-(2,3-diaminopropionylamino)propionic acid](dimethyl sulfoxide)platinum(II) complex, H Takashima; C Hirai; K Tsukahara, A new complex of chloro[3-(2,3-diaminopropionylamino)propionic acid](dimethyl sulfoxide)platinum(II) ([PtCl-(dmso)(Hdapap)]CF3CO2 center dot 2H(2)O) was synthesized and characterized. Among a series of nucleic acids, the selective and 1:1 binding between [PtCl(dapap)(dmso)] and a guanosine 5'-monophosphate ion (Hgmp(-)) in an aqueous solution at pH 4.0 (20 mmol dm(-3), each) was achieved by conducting ESI-MS and NMR experiments. This reaction included the initial chloride ion displacement by H2O, followed by metal coordination to the N7-position of the guanine base. The latter step was not affected in the case of guanosine-3',5'-cyclic monophosphate ion (cgmp(-)), indicating that the phosphate-Pt binding can be ruled out in this system. In order to monitor the binding reaction of [PtCl(dapap)(dmso)] with several nucleic acids, time-course H-1 and P-31 NMR experiments were performed at 25 degrees C. Changes in the NMR chemical shifts of H8, H1', and phosphate signals in Hgmp- upon the addition of [PtCl(dapap)(dmso)] revealed that two products finally remained. Since the synthetic dapap ligand could regulate the reactivity of a ligand coordinated to the Pt-center in [PtCl(dapap)(dmso)], this may arise from the presence of cis- and trans-isomers of [PtCl(dapap)(dmso)] in solution., Sep. 2005, 78, 9, 1629, 1634, Scientific journal
  • Refereed, ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, BLACKWELL MUNKSGAARD, Chloro(4,7-diphenyl-1,10-phenanthroline)(2,2 : 6 ',2 ''-terpyridine)ruthenium(II) hexafluorophosphate, N Yoshikawa; N Kanehisa; Y Kai; H Takashima; K Tsukahara, The title compound, [RuCl(C24H16N2)(C15H11N3)]PF6, consists of a monomeric Run complex cation and a hexafluorophosphate anion. The coordination environment about the Run atom is distorted octahedral, where the 2,2:6'2"-terpyridine (terpy) ligand is coordinated in a meridional fashion, the 4,7-diphenyl-1,10-phenanthroline (dpphen) ligand is coordinated in a cis fashion and the Cl atom is trans to one of the dpphen N atoms. The Ru-N bond distances are in the range 1.956 (5)-2.096 (5) Angstrom and the Ru-Cl distance is 2.403 (2) Angstrom., Mar. 2005, 61, 3, M545, M547, Scientific journal
  • Refereed, ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, WILEY-BLACKWELL, Acetonitrile(1,10-phenanthroline)(2,2 ': 6 ',2 ''-terpyridine)ruthenium(II) bis(hexafluorophosphate), N Yoshikawa; A Ichimura; N Kanehisa; Y Kai; H Takashima; K Tsukahara, The asymmetric unit of the title compound, [Ru(C2H3N)(phen)(terpy)](PF6)(2) [phen is 1,10-phenanthroline (C12H8N2) and terpy is 2,2': 6',2"-terpyridine (C15H11N3)] contains a monomeric [Ru(CH3CN)(phen)(terpy)](2+) cation and two hexafluorophosphate anions. The ligand environment about the Ru atom is distorted octahedral. The Ru-N distances are in the range 1.933 (5)-2.083 (5) Angstrom and the Ru-N(acetonitrile) distance is 2.016 (7) Angstrom., Jan. 2005, 61, 1, M55, M56, Scientific journal
  • Refereed, ANALYTICAL SCIENCES, JAPAN SOC ANALYTICAL CHEMISTRY, Electrochemical and luminescent properties of new mononuclear ruthenium(II) and binuclear iridium(III)-ruthenium(II) terpyridine complexes, N Yoshikawa; T Matsumura-Inoue; N Kanehisa; Y Kai; H Takashima; K Tsukahara, Hexafluorophosphate salts of mononuclear complexes [(RuCl)-Cl-II(L)(terpy)](+) (L = dmbpy (1); dpbpy (2), sambpy (3), and dpp (7), and binuclear complexes [(Ru2Cl2)-Cl-II(dpp)(terpy)(2)](2+) (8) and [(IrRuCl2)-Ru-III-Cl-II(dpp)(terpy)(2)](3+) (9) were prepared and characterized. Abbreviations of the ligands are bpy = 2,2'-bipyridine, dmbpy = 4,4'-dimetyl-2,2'-bipyridine, dpbpy = 4,4'-diphenyl-2,2'-bipyridine, dpp = 2,3-bis(2-pyridyl)pyrazine, sambpy = 4,4'-bis((S)-(+)-alpha-1-phenylethylamido)-2,2'-bipyridine, and terpy = 2,2':6',2"-terpyridine. The absorption spectra of 8 and 9 are dominated by ligand-centered bands in the UV region and by metal-to-ligand charge-transfer bands in the visible region. The details of their spectroscopic and electrochemical properties were investigated. In both binuclear complexes, it has been found that the HOMO is based on the Ru metal, and LUMO is dpp-based. [(IrRuCl2)-Ru-III-Cl-II(dpp)(terpy)(2)](3+), indicating intense emission at room temperature, and a lifetime of 154 ns. The long lifetime of this bimetallic chromophore makes it a useful component in the design of supramolecular complexes., Dec. 2004, 20, 12, 1639, 1644, Scientific journal
  • Refereed, ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, BLACKWELL MUNKSGAARD, cis-dichlorobis(di-2-pyridylamine)iridium(III) hexafluorophosphate, N Yoshikawa; J Sakamoto; N Kanehisa; Y Kai; H Takashima; K Tsukahara, The crystal structure of the title compound, [IrCl2(C10H9N3)(2)] PF6, contains a monomeric [IrCl2(bpya)(2)](+) cation (bpya is di-2-pyridylamine) and a hexafluorophosphate anion. The iridium(III) ion is coordinated by four N atoms from two bpya ligands [mean Ir - N distance = 2.049 ( 6) Angstrom] and two Cl atoms [Ir - Cl = 2.344 (2) Angstrom], forming a distorted octahedral environment., May 2004, 60, M546, M547, Scientific journal
  • Refereed, ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, BLACKWELL MUNKSGAARD, cis-dibrornobis(4,4 '-dimethyl-2,2 '-bipyridine)manganese(II), J Sakamoto; N Yoshikawa; H Takashima; K Tsukahara; N Kanehisa; Y Kai; K Matsumura, The title compound, [MnBr2(C12H12N2)(2)], has a twofold axis, and the Mn-II atom is coordinated by four N atoms from two 4,4'-dimethyl-2,2'-bipyridine (dmbpy) ligands and two bromide anions, forming a distorted octahedral environment. The Mn-N and Mn-Br bond distances are 2.261 (2)-2.297 (3) and 2.6193 (5) Angstrom, respectively. The dihedral angle between the pyridine rings of each dmbpy ligand is 16.09 (9)degrees., Apr. 2004, 60, 4, M352, M353, Scientific journal
  • Refereed, ANALYTICAL SCIENCES, JAPAN SOC ANALYTICAL CHEMISTRY, Electrochemical and phosphorescent properties of new Ir(III) complexes coordinated by various bipyridine derivatives, N Yoshikawa; J Sakamoto; T Matsumura-Inoue; H Takashima; K Tsukahara; N Kanehisa; Y Kai, Four useful polypyridine iridium(III) complexes in the form of [IrCl2L2](+) were prepared and their spectroscopic and electrochemical properties as well as X-ray crystallography were investigated. The ligands used were L = 2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine, 4,4'-diphenyl-2,2'-bipyridine, 1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, and 2,2'-biquinoline. Synthetic methods were developed by a sequential ligand-replacement, which occurred in the reaction vessel using a microwave oven. All complexes showed that LUMOs are based on the pi-system contribution of the polypyridine ligand for [IrCl2(bpy)(2)](+), [IrCl2(dmbpy)(2)](+), [IrCl2(dpbpy)(2)](+), [IrCl2(phen)(2)](+), [IrCl2(dpphen)(2)](+) and [IrCl2(bqn)(2)](+). The HOMOs are also localized on the polypyridine ligand in the iridium complexes. It was found that [IrCl2L2](+) emits intense phosphorescence at room temperature. In particular, the use of dpbpy as ancillary ligands extends the lifetime (660 ns) of the (3)(pi-pi*) excited states of Ir(III) polypyridine complexes. The complex [IrCl2(bqn)(2)](+) with electron acceptor substituents shows a large red-shift to 622 nm. It is noticed that iridium polypyridine complexes show intense emissions at various colors, such as yellow for [IrCl2(dmbpy)(2)](+) and red for [IrCl2(bqn)(2)](+), which can be applied to photosensitizers. The spectroscopic and electrochemical details are also reported herein., Apr. 2004, 20, 4, 711, 716, Scientific journal
  • Refereed, ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, BLACKWELL MUNKSGAARD, (11R)-(-)-N,N '-Dimethylcinchonidinium diiodide, N Yoshikawa; K Takemoto; J Sakamoto; N Kanehisa; Y Kai; H Takashima; K Tsukahara, The title compound, (-)-4-[hydroxy(1-methyl-5-vinyl-1-azoniabicyclo[2.2.2]oct-2-yl)methyl]-1-methylquinolinium diiodide, C21H28N2O2+.2I(-), is formed from optically active (11R)-(-)-cinchonidine and methyl iodide. The N-Me bond lengths are in the range of 1.476 (7)-1.497 (6) Angstrom., Feb. 2004, 60, 2, O281, O282, Scientific journal
  • Refereed, ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, BLACKWELL MUNKSGAARD, (11S)-(+)-N,N '-dimethylcinchoninium diiodide, N Yoshikawa; K Takemoto; J Sakamoto; N Kanehisa; Y Kai; H Takashima; K Tsukahara, The title compound, (+)-4-[hydroxy(1-methyl-5-vinyl-1-azoniabicyclo[2.2.2]oct-2-yl)methyl]-1-methylquinolinium diiodide, C21H28N2O2+.2I(-), is formed from optically active (11S)-(+)-cinchonine and methyl iodide. The N-Me bond lengths are in the range 1.48 (1)-1.49 (1) Angstrom., Jan. 2004, 60, 1, O17, O18, Scientific journal
  • Refereed, ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, WILEY-BLACKWELL, cis-dichlorobis(1,10-phenanthroline)iridium(111) hexafluorophosphate, N Yoshikawa; J Sakamoto; N Kanehisa; Y Kai; K Matsumura; H Takashima; K Tsukahara, The crystal structure of the title compound, [IrCl2(C12H8N2)(2)] PF6, contains a monomeric [IrCl2(phen)(2)](+) cation (phen is 1,10-phenanthroline) and a hexayuorophosphate anion. The iridium( III) ion is coordinated by four N atoms from two phen ligands [mean Ir - N distance 2.050 (5) Angstrom] and two Cl atoms [Ir - Cl = 2.343 (1) Angstrom], forming a distorted octahedral environment., Nov. 2003, 59, 11, M972, M974, Scientific journal
  • Refereed, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, CHEMICAL SOC JAPAN, Intramolecular electron-transfer pathway for deoxy and zinc myoglobins modified with N,N,N ',N '',N ''-diethylenetriaminepentaacetatocobaltate(III), K Tsukahara; M Nishimine; Y Shioyama; H Takashima; J Hirose, Horse heart metmyoglobin (metMib), whose N-terminal Glyl is linked by an N,N,N',N'',N''-diethylenetriamine-pentaacetatocobaltate(M) ion ([Co-III(dtpa)]) with an amide bond, was prepared and characterized. A one-electron reduced protein, [deoxyMb{Co-III(dtpa)}], was prepared by reduction with a methylviologen-radical cation, which was produced in situ by a photoreduction using a tris(2,2'-bipyridine)ruthenium(II) ion in the presence of disodium dihydrogen ethylenediaminetetraacetate at 25 degreesC, pH 7.5 (a 0.010 mol dm(-3) tris(hydroxymethyl)aminomethane-HCl buffer), and an ionic strength of 0.50 mol dm(-3) (NaCl). The reaction of [deoxyMb{Co-III(dtpa)}] to form [metMb{Co-II(dtpa)}] obeyed a first-order rate law on the protein concentration. The first-order rate constant was dependent on the concentration of the protein, indicating that both intra- and intermolecular electron-transfer (ET) processes simultaneously occur. The latter is the reaction with excess [metMb{Co-III(dtpa)}] remaining. Both intra- and intermolecular ET rates could be explained by the Marcus theory, including the distance dependence of the rate of the reaction, and might arise mainly from the very large reorganization energy for the Co(III)/Co(II) couple. Zinc-substituted myoglobin, [ZnMb{Co-III(dtpa)}], was also prepared and the photoinduced ET reaction from the excited triplet state of zinc myoglobin to the Co(M) moiety was examined. The observed ET quenching rate constant is reasonably explained by the Marcus theory through the same ET pathway as that for [deoxyMb{Co-III(dtpa)}]. It is suggested that the ET occurs with through-bond and van der Waals interactions from the heme edge to the Co(III) edge via Phe 138 and Len 137 over 18.8 Angstrom (1 Angstrom = 1 x 10(-10) m) both in deoxy and zinc myoglobins., Nov. 2003, 76, 11, 2135, 2142, Scientific journal
  • Refereed, ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, BLACKWELL MUNKSGAARD, (4,4 '-dimethyl-2,2 '-bipyridine)chloro-(2,2 ': 6 ',2 ''-terpyridine)-iridium(III) hexafluorophosphate, N Yoshikawa; J Sakamoto; N Kanehisa; Y Kai; T Matsumura-Inoue; H Takashima; K Tsukahara, In the title compound, [IrCl(C12H12N2)(C15H11N3)](PF6)(2), the ligand environment about the Ir atom is distorted octahedral. The 2,2':6',2"-terpyridine (terpy) ligand is coordinated in a meridional fashion, the 4,4'-dimethyl-2,2'-bipyridine (dmbpy) ligand coordinated in a cis fashion and the Cl atom is trans to one of the dmbpy N atoms. Ir-N bond distances are 1.971 (5)-2.065 (6) Angstrom and the Ir-Cl distance is 2.357 (2) Angstrom., Oct. 2003, 59, 10, M830, M832, Scientific journal
  • Refereed, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, CHEMICAL SOC JAPAN, Intramolecular electron transfer of cytochrome c modified with N,N,N ',N '',N ''-diethylenetriaminepentaacetatocobaltate(III), K Tsukahara; N Iida; Y Kaida; H Takashima; M Mizobe; R Arakawa, Horse heart cytochrome c (cytc) modified with an N,N,N',N",N"-diethylenetriaminepentaacetatocobaltate(III) ion, [cytc(III)Co(III)(dtpa))], was prepared and characterized. The major component of singly modified [cytc(III)Co(III)(dtpa))] contains a [Co-III(dtpa)] ion at Lys13, of which the epsilon-amino group is linked with a carboxylate ion of dtpa. A one-electron reduced protein, [cytc(II)(Co-III(dtpa)}], was prepared by reduction with a methylviologen-radical cation, which was produced in situ by a photoreduction using a tris(2,2'-bipyridine)ruthenium(II) ion in the presence of disodium dihydrogen ethylenediaminetetraacetate at 25 degreesC, pH 7.5 (0.010 mol dm(-3) tris(hydroxymethyl)aminomethane-HCl buffer), and an ionic strength of 0.50 mol dm(-3) (NaCl). The reaction of [cytc(II){Co-III(dtpa))] to form [cytc(III)[Co-II(dtpa))] was very slow, and was followed by conventional spectrophotometry. The reaction was of first order in the protein and the first-order rate constant ((3.1 +/- 0.5) x 10(-4) s(-1)) was independent of the concentration of the protein, indicating that the intramolecular electron-transfer (ET) process is predominant. The reaction mechanism is discussed on a through-bond or through-space pathway. The slow intramolecular ET rate might arise not only from the long distance. but also from the large reorganization energy for the Co(III)/Co(II) couple., Jul. 2003, 76, 7, 1323, 1328, Scientific journal
  • Refereed, ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE, WILEY-BLACKWELL, cis-Dichlorobis(2,2 '-biquinoline)iridium(III) hexafluorophosphate, N Yoshikawa; J Sakamoto; N Kanehisa; Y Kai; T Matsumura-Inoue; H Takashima; K Tsukahara, The crystal structure of the title compound, [IrCl2(bqn)(2)]PF6, (bqn is 2,2'-biquinoline, C18H12N2), contains a monomeric [IrCl2(bqn)(2)](+) cation and a hexafluorophosphate anion. The iridium(III) ion is coordinated by four N atoms from two bqn ligands [mean Ir-N distance 2.065 (5) Angstrom] and two Cl atoms [Ir-Cl=2.342 (2) and 2.353 (2) Angstrom], forming a distorted octahedral environment. Each 2,2'-biquinoline ligand is planar, the mean deviations from the least-squares planes being 0.2431 (6) and 0.1665 (6) Angstrom., Jul. 2003, 59, 7, M551, M552, Scientific journal
  • Refereed, JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY, SPRINGER-VERLAG, Remarkably stereoselective photoinduced electron-transfer reaction between zinc myoglobin and optically active binaphthyl bisviologen, H Takashima; M Tanaka; Y Hasegawa; K Tsukahara, We have designed and synthesized new optically active bisviologens ([BNMV](4+)) containing a binaphthyl moiety to examine the stereoselective photoinduced electron-transfer (ET) reactions with zinc-substituted myoglobin (ZnMb) by flash photolysis. The photoexcited triplet state of ZnMb, (3)(ZnMb)*, was successfully quenched by [BNMV]4+ ions to form the radical pair of a ZnMb cation (ZnMb(.+)) and a reduced viologen ([BNMV](.3+)), followed by a thermal ET reaction to the ground state. The rate constants (k(q)) for the ET quenching at 25 degreesC were obtained as k(q)(R)-(2.9 +/- 0.2)x 10(7) M-1 s(-1) and k(q)(S)=(2.2 +/- 0.2) x 10(7) M-1 s(-1), respectively. The ratio of k(q)(R)/k(q)(S) = 1. 3 indicates that the (R)-isomer of the chiral viologen preferentially quenches (3)(ZnMb)*. On the other hand, the rate constants (k) for the thermal ET reaction from [BNMV](.3+) to ZnMb(-+) at 25 degreesC were k(R)=(1.2 +/- 0.1) x 10(8) M-1 s(-1) and k(S)= (0.47 +/- 0.03) x 10(8) M-1 s(-1), respectively, and the ratio remarkably increased to k(R)/k(S)=2.6. The activation parameters, DeltaH(not equal) and AS', were determined from the kinetic measurements at various temperatures (10-30 degreesC) to understand the ET mechanisms. In the quenching reaction, the energy differences of DeltaDeltaH(not equal)(R-S) and TDeltaDeltaS(not equal) (R-S) at 25 degreesC were calculated to be -3.9 +/- 1.6 and -3.3 +/- 0.2 kJ mol(-1), respectively, whereas DeltaDeltaH(not equal) (R-S)-7.7 +/- 1.9 kJ mol(-1) and TDeltaDeltaS(not equal) (R-S)-9.9 +/- 0.5kJ mol(-1) were found for the thermal ET reaction. Therefore, the thermal ET reaction to the ground state was proved to be dominated by the entropy term, and the large stereoselectivity may arise from the decrease in charge repulsion between donor and acceptor., May 2003, 8, 5, 499, 506, Scientific journal
  • Refereed, The Chemical Educator, Microwave-Assisted Dehydration of Aqua Complexes, Naokazu Yoshikawa; Hiroshi Takashima, Dec. 2002, 7, 354, 355
  • Refereed, ELECTROCHEMISTRY, ELECTROCHEMICAL SOC JAPAN, Supramolecular construction of covalently and noncovalently-linked photoinduced electron transfer systems in myoglobin scaffold, H Takashima; YZ Hu; K Sano; S Shinkai; S Oishi; Hamachi, I, Zinc Protoporphyrin IX-based compound 1 connected with ruthenium tris-bipyridine and beta -cyclodextrin and its reconstituted Myoglobin(Mb(1)) were newly synthesized to construct covalently and non-covalently linked electron transfer reactions using semisynthetic protein. In the presence of an electron acceptor such as anthraquinone, Mb(1) can bind it on the surface and form a self-assembled donor-sensitizer-acceptor triad. The final charge separated state via stepwise electron transfer was generated after photo-excitation of the ruthenium complex by laser flash photolysis., Dec. 2001, 69, 12, 942, 945, Scientific journal
  • Refereed, JOURNAL OF INORGANIC BIOCHEMISTRY, ELSEVIER SCIENCE INC, Extremely slow intramolecular electron transfer in cytochrome c modified with a diethylenetriaminepentaacetatocobaltate(III) complex, K Tsukahara; Y Kaida; N Iida; H Takashima; M Mizobe; R Arakawa, Aug. 2001, 86, 1, 462, 462
  • Refereed, CHEMISTRY-A EUROPEAN JOURNAL, WILEY-V C H VERLAG GMBH, Direct comparison of electron transfer properties of two distinct semisynthetic triads with non-protein based triad: Unambiguous experimental evidences on protein matrix effects, YZ Hu; H Takashima; S Tsukiji; S Shinkai; T Nagamune; S Oishi; Hamachi, I, In order to understand the roles of protein matrix in electron transfer processes (ET) within biological systems, a heme-based donor (Zn-heme: ZnPP)-sensitizer (Ru2+(bpy)(3))-acceptor (cyclic viologen: BXV4+) triad 1 was used as a probe molecule. Two semisynthetic systems, Cyt-b(562)(1) and Mb(1), in which the triad is incorporated into cytochrome b(562) (Cyt-b(562)) or into myoglobin (Mb), were constructed by cofactor reconstitution. These two semisynthetic proteins were compared with the triad itself (i.e., without the protein matrix) using absorption spectroscopy, steady state emission and excitation studies, laser flash photolysis experiments, and molecular modeling. Photoexcitation of the ZnPP moiety of Cyt-b(562)(1) or Mb(1) leads to a direct ET from the triplet state of ZnPP state ((ZnPP)-Zn-3) to BXV4+ to generate a final charge-separated (CS) state, Cyt-b(562)(Zn+)-Ru2+-BXV3+. or Mb(Zn+)-Ru2+-BXV3+.. On the other hand, direct ET from the excited ZnPP moiety to the BXV4+ moiety is also involved in 1 in the absence of the protein matrix, but the excited state of ZnPP involved is not (ZnPP)-Zn-3, but the singlet excited state ((ZnPP)-Zn-1) in this pathway. When the Ru2+(bpy)(3) moiety of Cyt-b(562)(1) or Mb(1) is excited, a stepwise ET relay occurs with the ion-pair, Cyt-b(562)(Zn)Ru3+-BXV3+. or Mb(Zn)-Ru3+-BXV3+. as an intermediate, leading to the same final CS state as that generated in the direct ET pathway. The lifetimes of the corresponding final CS states were determined to be 300 ns for 1 in the absence of the protein matrix, 600-900 ns for Cyt-b(562)(1) and 1.1-18 mu s for Mb(1), the values of which are greatly affected by the protein matrix. Molecular modeling study of the three systems consistently explained the differences of their photophysical behavior., Jun. 2000, 6, 11, 1907, 1916, Scientific journal
  • Refereed, CHEMICAL COMMUNICATIONS, ROYAL SOC CHEMISTRY, Cyclodextrin-appended myoglobin as a tool for construction of a donor-sensitizer-acceptor triad on a protein surface, Hamachi, I; H Takashima; YZ Hu; S Shinkai; S Oishi, A protein-based and noncovalently-linked donor-sensitizer-acceptor triad has been prepared by self-assembly via mechanical linkages and hydrophobic interactions, and its photoinduced electron transfer properties have been studied., 2000, 13, 1127, 1128, Scientific journal
  • Not Refereed, Otsuka Commune, 生体分子インターフェースとしてのデンドリマー:非対称性ルテニウム錯体によるシトクロムcの光還元, TAKASHIMA Hiroshi, 2000, 2-3
  • Refereed, CHEMISTRY LETTERS, CHEMICAL SOC JAPAN, Electron transfer from Zn-protoporphyrin IX to ruthenium ammine attached at His63 of reconstituted cytochrome b562, Hamachi, I; H Takashima; S Tsukiji; S Shinkai; T Nagamune; S Oishi, Site-specific modification of Cytochrome b562 With ruthenium ammine (RuA5) at 63-His was successfully carried out. Electron transfer rate from ZnPP in the heme crevice to Ru(III)A5 coordinated to 63-His on the protein surface was determined by the laser flash photolysis., Jul. 1999, 28, 7, 551, 552, Scientific journal
  • Refereed, JOURNAL OF INCLUSION PHENOMENA AND MACROCYCLIC CHEMISTRY, SPRINGER, Chiral recognition of phenylacetic acid derivatives by aminated cyclodextrins, T Kitae; H Takashima; K Kano, Chiral recognition of mandelic acid (1), acetylmandelic acid (2), 1-methoxyphenyl acetic acid (3), phenylsuccinic acid (4), 2-phenylpropanoic acid (5) and ibuprofen (6) in their anionic forms by protonated 6(A)-amino-6(A)-deoxy-beta-cyclodextrin (mono-NH3+-beta-CD) and 6(A),6(D)-diamino-6(A),6(D)-dideoxy-beta-cyclodextrin (di-NH3+-beta-CD) has been studied by means of capillary zone electrophoresis (CZE) and H-1 NMR spectroscopy. Both methods show the preferable guests for mono-NH3+-beta-CD to be the (R)-enantiomers of 1, 3 and 5 and the (S)-enantiomers of 2, 4 and 6. Cooperative work of Coulomb interactions and inclusion is essential for chiral recognition of these anionic guests., Mar. 1999, 33, 3, 345, 359, Scientific journal
  • Refereed, Journal of Inclusion Phenomena, Springer Netherlands, Chiral recognition of phenylacetic acid derivatives by aminated cyclodextrins, Takashi Kitae; Hiroshi Takashima; Koji Kano, Chiral recognition of mandelic acid (1), acetylmandelic acid (2), 1-methoxyphenylacetic acid (3), phenylsuccinic acid (4), 2-phenylpropanoic acid (5) and ibuprofen (6) in their anionic forms by protonated 6A-amino-6A-deoxy-β-cyclodextrin (mono-NH+ 3-β-CD) and 6A,6D-diamino-6A,6D-dideoxy-β-cyclodextrin (di-NH+ 3-β-CD) has been studied by means of capillary zone electrophoresis (CZE) and 1H NMR spectroscopy. Both methods show the preferable guests for mono-NH+ 3-β-CD to be the (R)-enantiomers of 1, 3 and 5 and the (S)-enantiomers of 2, 4 and 6. Cooperative work of Coulomb interactions and inclusion is essential for chiral recognition of these anionic guests., 1999, 33, 3, 345, 359, Scientific journal
  • Refereed, CHEMICAL COMMUNICATIONS, ROYAL SOC CHEMISTRY, Ru(bpy)(3)-based artificial receptors toward a protein surface: selective binding and efficient photoreduction of cytochrome C, H Takashima; S Shinkai; Hamachi, I, The binding properties of a series of Ru(bpy)(3) complexes to cytochrome c are described; these compounds act as selective cytochrome c receptors and one derivatie is shown to be a photodriven modulator of the cytochrome c redox state., 1999, 23, 2345, 2346, Scientific journal
  • Refereed, CHEMISTRY LETTERS, CHEMICAL SOC JAPAN, Entropy-dominating strong binding of carboxylate anions to protonated aminocyclodextrin, K Kano; T Kitae; H Takashima; Y Shimofuri, Protonated heptakis(6-amino-6-deoxy)-beta-cyclodextrin complexes with p-methylbenzoate and N-acetylrryptophan anions more strongly than a monoamino-beta-cyclodextrin cation. Such a strong association is dominated by large and positive entropy changes for complexation which might be due to extensive dehydration from both host and guest upon complexation., 1997, 26, 9, 899, 900, Scientific journal
  • Refereed, JOURNAL OF INCLUSION PHENOMENA AND MOLECULAR RECOGNITION IN CHEMISTRY, KLUWER ACADEMIC PUBL, Use of electrostatic interaction for chiral recognition. Enantioselective complexation of anionic binaphthyls with protonated amino-beta-cyclodextrin, K Kano; T Kitae; H Takashima, The studies using NMR and capillary zone electrophoresis clearly reveal that protonated 6(A)-amino-6(A)-deoxy-beta-cyclodextrin recognizes the chirality of anionic binaphthyl derivatives such as 1,1'-binaphthyl-2,2'-diyl phosphate and 1,1'-binaphthyl-2,2'-dicarboxylate through electrostatic interaction between the host and the guest and simultaneous inclusion., 1996, 25, 1-3, 243, 248, Scientific journal
  • Refereed, KOBUNSHI RONBUNSHU, SOC POLYMER SCIENCE JAPAN, Preparation of poly(vinyl chloride)/amphiphilic cyclodextrin composite films and their chiral recognition ability, K Kano; H Takashima; Y Taniuchi, The poly(vinylchloride) (PVC) thin films embedding amphiphilic cyclodextrins at the one sides of the films have been prepared by spreading the solutions of the mixtures of PVC and cyclodextrin derivatives in THF-toluene on water. The XPS analyses indicate that the hydrophilic cyclodextrin head groups are arranged at the surfaces of the polymer films. The chiral recognition of such cyclodextrin films has been studied by dipping the films in the aqueous solutions of (R)- and (S)-1,1'-binaphthyl-2,2'-diylphosphates (BNP) and analyzing the films by means of XPS spectroscopy. The (S)-BNP is preferentially bound to the cyclodextrin-embedding PVC films, which is in agreement with the results obtained for the homogeneous aqueous system as well as those for the cyclodextrin monolayer and LB membranes. The enantiomer selectivity of the film is altered by the dipping time. The XPS and FT-IR measurements indicate that the 2-naphthoate anion in water is bound to the cyclodextrin film in its salt form. Deducing from this result, the BNP anion in water seems to be transferred to the cyclodextrin film in its salt form. It is assumed that the chiral recognition is achieved by the enantioselective inclusion of BNP into the cyclodextrin cavity at the surface of the PVC film., 1996, 53, 9, 542, 547, Scientific journal
  • Trends in Photochemistry & Photobiology, Structures, DFT calculations and emission properties of protonated adenine, cytosine and guanine bases, Naokazu Yoshikawa; Shoko Yamazaki; Kana Kimori; Yuna Kakimoto; Kanako Mito; Shiori Eguchi; Risa Yokoyama; Nobuko Kanehisa; Norimitsu Tohnai; Eiji Nakata; Hiroshi Takashima, Dec. 2020, 19, 1, 16, Scientific journal
  • Refereed, Journal of Photochemistry and Photobiology, Elsevier BV, Photophysical and elecron-transfer reaction properties of tris(2,2’-bipyridine)ruthenium(II)-based inhibitors that covalently bound to the active site of chymotrypsin, Hiroko Kimura; Natsuko Nagasato; Natsumi Kato; Mei Kojima; Chisato Enomoto; Eiji Nakata; Hiroshi Takashima, Mar. 2021, 6, 100027, 100027, Scientific journal
  • Refereed, Journal of Molecular Structure, Emission properties of 1,10-phenanthroline derivatives induced by protonation of a nitrogen atom, Naokazu Yoshikawa; Shoko Yamazaki; Yuna Kakimoto; Shiori Eguchi; Risa Yokoyama; Nobuko Kanehisa; Norimitsu Tohnai; Eiji Nakata; Hiroshi Takashima, May 2021, 1242, 130728, Scientific journal
  • Refereed, Journal of Inclusion Phenomena and Macrocyclic Chemistry, Springer Science and Business Media LLC, Circularly polarized luminescence (CPL) characteristics of hydrophobic pyrene derivatives/γ-cyclodextrin (γ-CD) complexes in aqueous solution dissolved by grinding, Mika Sawai; Sayaka Matsumoto; Yuki Mimura; Yoshitane Imai; Shoko Yamazaki; Nobuko Kanehisa; Norimitsu Tohnai; Eiji Nakata; Hiroshi Takashima, Circularly polarized luminescence (CPL) organic dyes are currently receiving a great interest, but there are still not many reported observations of CPL spectra of hydrophobic dyes from aqueous solution. We have prepared hydrophobic pyrene derivatives and dissolved them into aqueous solutions with gamma-cyclodextrin (gamma-CD) by using grinding technique. Among these derivatives, (pyrene-1-carbonyl)serine (PySer) forms a spatially restricted dimer in the hydrophobic chiral cavity of gamma-CD and exhibits excimer emission with a high quantum yield of Phi(f) = 0.68. In addition, circular dichroism and CPL signals were induced for the complex. The strong g(CPL) value of g(CPL) = + 2.2 x 10(-3) was obtained, which may be attributed to the interaction between the hydroxyl groups in the side chain of PySer with those of gamma-CD and it strengthens the chiral dimeric structure., Jan. 2022, 102, 1-2, 133, 142, Scientific journal
  • Refereed, Journal of Molecular Structure, Elsevier BV, Structures, Atomic Charges, Emission Properties and DFT studies of Biquinoline Derivatives Induced by Protonation of a Nitrogen Atom, Naokazu Yoshikawa; Shoko Yamazaki; Ayaka Nishiyama; Yuki Yamashita; Nobuko Kanehisa; Norimitsu Tohnai; Eiji Nakata; Hiroshi Takashima, Jan. 2022, 1251, 131990, 131990, Scientific journal
  • Not Refereed, 細胞, 光増感金属錯体の酵素活性中心への導入と 光誘起電子移動によるラジカル生成反応系の構築, 高島弘, Jan. 2022, 54, 1, 27, 30, In book
  • Refereed, The Journal of Organic Chemistry, American Chemical Society (ACS), Intramolecular Diels–Alder Reactions of α-Bromostyrene-Functionalized Unsaturated Carboxamides, Zhichao Wang; Shoko Yamazaki; Yuji Mikata; Miho Oba; Hiroshi Takashima; Tsumoru Morimoto; Akiya Ogawa, Aug. 2022, 87, 11148, 11164, Scientific journal
  • Refereed, Journal of Molecular Structure, Octahedrons of 1,10-phenanthroline and 4'-chloro-2,2':6',2''-terpyridine induced by protonation of nitrogen atoms: synthesis and structural analysis, Naokazu Yoshikawa; Shoko Yamazaki; Shiori Eguchi; Ayaka Nishiyama; Yuki Yamashita; Norimitsu Tohnai; Eiji Nakata; Hiroshi Takashima, Jan. 2023, 1271, 134075, Scientific journal

MISC

  • Jan. 2022, 54, 1, 27, 30
  • Not Refereed, ホスト-ゲスト・超分子化学シンポジウム講演要旨集, 疎水性ピレン誘導体とγ‐CD複合体の水中での円偏光発光特性, 沢井美香; 高島弘; 恒石響; 味村優輝; 今井喜胤, 18 May 2019, 17th, 69
  • Not Refereed, ホスト-ゲスト・超分子化学シンポジウム講演要旨集, シクロデキストリンを用いた疎水性ピレン誘導体の水中での光特性, 高島弘; 沢井美香; 恒石響; 味村優輝; 今井喜胤, 18 May 2019, 17th, 26
  • Not Refereed, 教育システム研究, サイエンス・オープンラボを通した化学(電池の歴史、化学発光)学習ー大学生による演示実験を動機付けにした高等学校授業開発研究ー, TAKASHIMA Hiroshi; TAKEUCHI Takae; MIKATA Yuji; URA Yasuyuki; NAKAJIMA Takayuki; MATSUURA Noriyuki, Mar. 2019, 14, 103, 111
  • Not Refereed, 教育システム研究, サイエンス・オープンラボを通した化学(有機合成、酸化還元、界面活性剤)学習ー大学生による演示実験を動機付けにした高等学校授業開発研究ー, MIKATA Yuji; TAKEUCHI Takae; TAKASHIMA Hiroshi; MATSUURA Noriyuki; HASE, Mar. 2018, 13, 429, 436
  • Not Refereed, 日本化学会春季年会講演予稿集(CD-ROM), キモトリプシンを用いた新奇な円偏光発光(CPL)システムの構築, 日比野可奈子; 高島弘; 原伸行; 今井喜胤, 03 Mar. 2017, 97th, ROMBUNNO.1PB‐122
  • Not Refereed, 日本化学会講演予稿集, Recognition of Helicity by Non-cyclic Oligosaccharides., 高岡涼子; 高島弘; 加納航治; 山口雅彦; 大久保仁; 平間正博, Mar. 1997, 72nd, 2, 686
  • 日本化学会春季年会講演予稿集(CD-ROM), Circularly polarized light (CPL) characteristics in water using hydrophobic pyrene derivative / γ-CD complexes., 沢井美香; 高島弘; 味村優輝; 今井喜胤, 2020, 100th
  • 基礎有機化学討論会要旨集, ピレン-シクロデキストリン超分子発光体の非古典的円偏光発光(CPL)特性制御, 味村優輝; 本村友希; 沢井美香; 靜間基博; 北松瑞生; 高島弘; 今井喜胤, 2019, 30th
  • シクロデキストリンシンポジウム講演要旨集, 円偏光発光(CPL)特性を有するシクロデキストリン-ピレン超分子発光体の開発, 味村優輝; 高桑栄; 本村友希; 沢井美香; 靜間基博; 北松瑞生; 北松瑞生; 高島弘; 今井喜胤; 今井喜胤, 2019, 36th
  • 光化学討論会要旨集(CD-ROM), シクロデキストリン-ピレン超分子発光体の円偏光発光(CPL)チューニング, 味村優輝; 高桑栄; 沢井美香; 本村友希; 靜間基博; 北松瑞生; 高島弘; 今井喜胤, 2019, 2019

Presentations

  • 木守佳那; 中田栄司; 高島弘, 第14回有機π電子系シンポジウム, 酵素活性部位に結合したトリスビピリジン型ルテニウム錯体の光誘起電子移動反応, 08 Jan. 2021
  • Hiroshi TAKASHIMA; Kana Kimori; Eiji Nakata, The 11th International Symposium of Advanced Energy Science\n~ Beyond the Decade of Zero Emission Energy ~, Photoinduced electron-transfer reactions of metal complexes as photosensitizers bound to the active site of enzyme, 15 Sep. 2020, rm:research_project_id
  • 柿本悠奈; 高島弘; 味村優輝; 今井喜胤, 2020年web光化学討論会, Circularly Polarized Luminescence of Anthracene derivative with cyclodextrin in solid state, 11 Sep. 2020, 09 Sep. 2020, 11 Sep. 2020
  • 沢井 美香; 高島 弘; 味村 優輝; 今井 喜胤, 日本化学会第100春季年会, 疎水性ピレン誘導体/γ-CD複合体を用いた水中での円偏光発光(CPL)特性, 23 Mar. 2020, False
  • 木守 佳那; 高島 弘; 中田 栄司, 日本化学会第100春季年会, チロシン残基を導入したトリスビピリジン型ルテニウム(II)錯体の光特性, 22 Mar. 2020, False
  • 吉川直和; 山崎祥子; 金久展子; 中田栄司; 加藤なつみ; 窪田曙; 沢井美香; 高島 弘, 日本結晶学会令和元年度年会および総会, ターピリジンへのプロトンとアニオン付加による蛍光特性の変化とDFT計算, Nov. 2019, 日本結晶学会, False
  • TAKASHIMA Hiroshi; Hiroshi TAKASHIMA; Natsumi Kato; Eiji Nakata, The 10th International Symposium of Advanced Energy Science\n~ Beyond the Decade of Zero Emission Energy ~, Photoinduced electron-transfer reactions of metal complexes as photosensitizers bound to the active site of enzyme, 05 Sep. 2019, 京都大学エネルギー理工研究所, 京都大学エネルギー理工研究所, False, rm:research_project_id
  • TAKASHIMA Hiroshi, 錯体化学会第69回討論会, 酵素活性中心へ導入したトリスビピリジン型ルテニウム(II)錯体の光電子移動反応, Sep. 2019, 錯体化学会, 名古屋大学(名古屋市), False
  • TAKASHIMA Hiroshi, 第30回基礎有機化学討論会, 円偏光発光(CPL)特性を有するピレン-シクロデキストリン超分子発光体の創製, Sep. 2019, 基礎有機化学会, 大阪国際交流センター, False
  • TAKASHIMA Hiroshi; Naokazu Yoshikawa; Shoko Yamazaki; Natsumi Kato; Mika Sawai; Kaoru Noda; Nobuko Kanehisa; Tsuyoshi Inoue; Eiji Nakata; Hiroshi Takashima, 31st Nano Congress for Future Advancements, Anion influence of emission properties and DFT calculations of diprotonated and triprotonated terpyridines, Aug. 2019, ConferenceSeries llc LTD, ロンドン, True
  • TAKASHIMA Hiroshi, 第17回ホストゲスト・超分子化学シンポジウム, 疎水性ピレン誘導体とγ-CD複合体の水中での円偏光発光特性, May 2019, ホストゲスト・超分子化学研究会, 金沢歌劇座, False
  • TAKASHIMA Hiroshi, 第17回ホストゲスト・超分子化学シンポジウム, シクロデキストリンを用いた疎水性ピレン誘導体の水中での光特性, May 2019, ホストゲスト・超分子化学研究会, 金沢歌劇座, False
  • TAKASHIMA Hiroshi, 第17回ホストゲスト・超分子化学シンポジウム, ピレン-シクロデキストリン超分子発光体における非古典的円偏光発光(CPL)特性制御, May 2019, ホストゲスト・超分子化学研究会, 金沢歌劇座, False
  • TAKASHIMA Hiroshi, 日本化学会第99春季年会, 疎水性ピレン誘導体とγ-CDを用いた水中での円偏光発光 (CPL)システムの構築, Mar. 2019, 日本化学会, 甲南大学 岡本キャンパス, False
  • TAKASHIMA Hiroshi, 日本結晶学会2018年度年会および総会, ポリピリジンのプロトン付加体の合成・X線結晶構造解析とDFT計算, Nov. 2018, 東京工業大学 大岡山キャンパス, False
  • TAKASHIMA Hiroshi; Hiroshi TAKASHIMA; Natsumi Kato; Eiji Nakata, The 9th International Symposium of Advanced Energy Science\n~ Interplay for Zero-Emission Energy ~, Photoinduced electron-transfer reactions of metal complexes as photosensitizers bound to the active site of enzyme, Sep. 2018, 京都大学エネルギー理工研究所, 京都大学エネルギー理工研究所, False
  • TAKASHIMA Hiroshi; Naokazu Yoshikawa; Shoko Yamazaki; Natsumi Kato; Akari Kubota; Mika Sawai; Kaoru Noda; Nobuko Kanehisa; Tsuyoshi Inoue; Hiroshi Takashima, 25th Nano Congress for Future Advancements, Synthesis, x-ray crystal structure, emission property, and DFT calculation of monoprotonated polypyridine, Aug. 2018, ConferenceSeries llc LTD, アイルランド, True
  • TAKASHIMA Hiroshi, 錯体化学会第68回討論会, 酵素活性中心に結合させたトリスビピリジン型ルテニウム(II)錯体の光誘起電子移動反応, Jul. 2018, 錯体化学会, 仙台国際センター(仙台市), False
  • TAKASHIMA Hiroshi, 第16回ホストーゲスト・超分子化学シンポジウム, 疎水性ピレン誘導体のシクロデキストリンによる水中でのエキシマーおよび円偏光蛍光, Jun. 2018, 東京理科大学 野田キャンパス, False
  • TAKASHIMA Hiroshi, 第45回生体分子科学討論会, 酵素活性阻害能をもつチロシン含有トリスビピリジン型ルテニウム(II)錯体の合成と光物理的性質, Jun. 2018, 第45回生体分子科学討論会実行委員会, 大阪市立大学 田中記念館, False
  • TAKASHIMA Hiroshi; Natsumi Kato; Hiroshi Takashima, IUPAC Analytical Chemistry Division Workshop, Synthesis of tris(2,2'-bipyridine)ruthenium(II) complex containing tyrosine molecules and its introduction into active site of chymotrypsin., Apr. 2018, Nara Women's University, True
  • TAKASHIMA Hiroshi, 平成29年度 日本結晶学会年会および会員総会, ポリピリジン配位子を含むルテ二ウム(II)錯体の三重項状態と遷移状態の研究, Nov. 2017, False
  • TAKASHIMA Hiroshi; Hiroshi TAKASHIMA; Saki OKAGUCHI; Eiji Nakata, The 8th International Symposium of Advanced Energy Science\n~ Interdisciplinary Approach to Zero-Emission Energy ~, Photoinduced electron-transfer reactions of metal complexes as photosensitizers bound to the active site of enzyme, Sep. 2017, 京都大学エネルギー理工研究所, 京都大学エネルギー理工研究所, False
  • TAKASHIMA Hiroshi, 錯体化学会第67回討論会, シクロデキストリンを用いたタンパク質活性中心への金属ポルフィリンの導入と光特性, Sep. 2017, 錯体化学会, 北海道大学, False
  • TAKASHIMA Hiroshi, 第15回ホストーゲスト・超分子化学シンポジウム, シクロデキストリンを用いた金属ポルフィリンのタンパク質活性中心への導入と光特性, Jun. 2017, 立命館大学びわこくさつキャンパス, False
  • TAKASHIMA Hiroshi, 第15回ホストーゲスト・超分子化学シンポジウム, シクロデキストリンを用いた酵素活性中心への金属ポルフィリンの導入と光特性, Jun. 2017, False
  • TAKASHIMA Hiroshi, 日本化学会第97春季年会, キモトリプシンを用いた新奇な円偏光発光(CPL)システムの構築, Mar. 2017, 日本化学会, 慶応義塾大学 日吉キャンパス, False
  • TAKASHIMA Hiroshi, 日本化学会第97春季年会, キモトリプシン活性中心へ導入したポルフィリン亜鉛錯体の光物性, Mar. 2017, 日本化学会, 慶応義塾大学 日吉キャンパス, False
  • TAKASHIMA Hiroshi, 日本化学会第97春季年会, シクロデキストリンを用いた疎水性ポルフィリンのタンパク質への導入, Mar. 2017, 日本化学会, 慶応義塾大学 日吉キャンパス, False
  • TAKASHIMA Hiroshi, 日本油化学会第55年会, キモトリプシン(CHT)を用いる新奇な円偏光発光(CPL)システムの構築, Sep. 2016, 奈良女子大学, False
  • TAKASHIMA Hiroshi, 錯体化学会第66回討論会, キモトリプシン活性中心へ導入した亜鉛ポルフィリンの光特性, Sep. 2016, 錯体化学会, 福岡大学七隈キャンパス(〒814-0180 福岡市城南区七隈八丁目19-1), False
  • TAKASHIMA Hiroshi, 第28回配位化合物の光化学討論会, 混合配位子を含むルテ二ウム(II)錯体の励起三重項状態の研究とDFT計算, Aug. 2016, 複合系の光機能研究会, 京都工芸繊維大学(606-8585 京都府京都市左京区松ヶ崎橋上町), False
  • TAKASHIMA Hiroshi, 第28回配位化合物の光化学討論会, キモトリプシン活性中心に結合したトリスビピリジン型ルテニウム(II)錯体の光誘起電子移動反応, Aug. 2016, 複合系の光機能研究会, 京都工芸繊維大学(606-8585 京都府京都市左京区松ヶ崎橋上町), False
  • TAKASHIMA Hiroshi, 第14回ホスト・ゲスト化学シンポジウム, キ?モ?ト?リ?プ?シ?ン?活?性?中?心?へ?導?入?し?た?ト?リ?ス?ビ?ピ?リ?ジ?ン?型?ル?テ?ニ?ウ?ム?(?I?I?)?錯?体?の?光?誘?起?電?子?移?動?反?応, Jun. 2016, ホスト-ゲスト・超分子化学研究会, 高知城ホール (〒780-0850高知県高知市丸ノ内二丁目1番10号), False
  • TAKASHIMA Hiroshi, 第14回ホスト・ゲスト化学シンポジウム, キモトリプシン活性阻害剤を導入した亜鉛ポルフィリンの合成と特性, Jun. 2016, ホスト-ゲスト・超分子化学研究会, 高知城ホール (〒780-0850高知県高知市丸ノ内二丁目1番10号), False
  • TAKASHIMA Hiroshi, 日本化学会第96春季年会, キモトリプシン活性中心に結合させたトリスビピリジン型ルテニウム(II)錯体の光誘起電子移動反応, Mar. 2016, 日本化学会, 同志社大学 京田辺キャンパス, False
  • TAKASHIMA Hiroshi, 日本化学会秋季事業 第5回 CSJ化学フェスタ2015, キモトリプシン活性中心に結合したトリスビピリジン型ルテニウム(II)錯体の光物理的性質および光誘起電子移動反応, Oct. 2015, 東京都江戸川区 タワーホール船堀, False
  • TAKASHIMA Hiroshi, 2015年 光化学討論会, テトラピリジルピラジンのプロトン付加体の発光特性とDFT計算, Sep. 2015, 大阪市立大学 杉本キャンパス(大阪市住吉区), False
  • TAKASHIMA Hiroshi, 錯体化学会第65回討論会, キモトリプシン修飾部位を複数導入したトリスビピリジン型ルテニウム(II)錯体の合成と光物理的性質, Sep. 2015, 奈良女子大学, False
  • TAKASHIMA Hiroshi, 日本化学会第95春季年会, カルボニックアンヒドラーゼ活性阻害部位を導入した種々のトリスビピリジン型ルテニウム(II)錯体の光誘起電子移動反応, Mar. 2015, 日本大学理工学部 船橋キャンパス, False
  • TAKASHIMA Hiroshi, 日本化学会第95春季年会, トリスビピリジン型ルテニウム(II)錯体を活性中心へ導入したキモトリプシンの光誘起電子移動反応, Mar. 2015, 日本大学理工学部 船橋キャンパス, False
  • TAKASHIMA Hiroshi, 日本化学会秋季事業 第4回 CSJ化学フェスタ2014, キモトリプシン活性中心へ導入したトリスビピリジン型ルテニウム(II)錯体の光誘起電子移動反応, Oct. 2014, 日本化学会, 東京都江戸川区 タワーホール船堀, False
  • TAKASHIMA Hiroshi, 錯体化学会第64回討論会, カルボニックアンヒドラーゼ活性阻害部位を複数導入したトリスビピリジン型ルテニウム(II)錯体の光誘起電子移動反応, Sep. 2014, 中央大学理工学部 後楽園キャンパス, False
  • TAKASHIMA Hiroshi, 錯体化学会第64回討論会, キモトリプシン活性中心へ導入したトリスビピリジン型ルテニウム(II)錯体の光誘起電子移動反応, Sep. 2014, 中央大学理工学部 後楽園キャンパス, False
  • TAKASHIMA Hiroshi, 錯体化学会第63回討論会, トリスビピリジン型ルテニウム(II)錯体のキモトリプシンへの導入と光特性, Nov. 2013, 琉球大学 千原キャンパス, False
  • TAKASHIMA Hiroshi; Hiroshi Takashima, New Trends of Nano- or Bio-materials Design in Supramolecular Chemistry, PHOTOINDUCED ELECTRON TRANSFER REACTIONS OF WATER SOLUBLE QUANTUM DOT COORDINATED BY CYTOCHROME C, Sep. 2013, 九州大学医学部キャンパス, True
  • TAKASHIMA Hiroshi, 第25回配位化合物の光化学討論会, DFT計算と発光エネルギーによるポリピリジン配位子を含むルテ二ウム(II)錯体の励起三重項状態の研究, Aug. 2013, 佐賀県唐津市 唐津ロイヤルホテル, False
  • TAKASHIMA Hiroshi, 日本化学会第93春季年会, 水溶性CdSe/ZnS(コア/シェル型)量子ドットを利用したシトクロムcの光還元反応, Mar. 2013, 立命館大学びわこ・くさつキャンパス
  • TAKASHIMA Hiroshi, 錯体化学会第62回討論会, 銅置換カルボニックアンヒドラーゼの調整と非対称トリスビピリジン型ルテニウム(II)錯体との相互作用, Sep. 2012, 富山大学五福キャンパス, False
  • TAKASHIMA Hiroshi, 錯体化学会第62回討論会, 亜硝酸還元酵素活性中心モデル銅(II)錯体を結合した亜鉛ミオグロビンの調製と光特性, Sep. 2012, 富山大学五福キャンパス, False
  • TAKASHIMA Hiroshi, 第24回配位化合物の光化学討論会, DFT計算によるターピリジンとアニオン配位子を含むイリジウム(III)錯体の三重項状態の研究, Aug. 2012, 東京大学 駒場リサーチキャンパス
  • TAKASHIMA Hiroshi, 錯体化学若手の会 近畿地区勉強会, 金属蛋白質表面での相互作用を利用した光誘起電子・エネルギー移動反応, Jun. 2012, 錯体化学若手の会, 京都大学吉田キャンパス, False
  • TAKASHIMA Hiroshi, 日本化学会第92春季年会, トリスビピリジン型ルテニウム(II)錯体にビオローゲンを結合させたカルボニックアンヒドラーゼ活性阻害剤の合成と光特性, Mar. 2012, False
  • TAKASHIMA Hiroshi, 日本化学会第92春季年会, 亜硝酸還元酵素活性中心モデル銅錯体を結合した亜鉛ポルフィリンの合成と光特性, Mar. 2012
  • TAKASHIMA Hiroshi, 日本化学会第92春季年会, カルボニックアンヒドラーゼ活性阻害部位を複数導入したトリスビピリジン型ルテニウム(II)錯体の酵素活性阻害能, Mar. 2012, False
  • 高島弘; 木守佳那; 柿本悠奈; 中田栄司, 京都大学エネルギー理工学研究所ゼロエミッションエネルギー研究拠点共同利用・共同研究成果報告会, 酵素活性中心に導入した光増感金属錯体の 光誘起電子移動反応, 09 Mar. 2021, 09 Mar. 2021, 09 Mar. 2021, rm:research_project_id
  • 高島弘; 中田栄司, 第32回配位化合物の光化学討論会, トリプシン活性中心へ導入したトリスビピリジン型ルテニウム(II)錯体の光誘起電子移動反応, Oral presentation, 09 Aug. 2021, 09 Aug. 2021, 10 Aug. 2021, rm:research_project_id
  • Hiroshi TAKASHIMA; Yuna Kakimoto; Shiori Eguchi; Risa Yokoyama; Eiji Nakata, The 12nd International Symposium of Advanced Energy Science\n~ Beyond the Decade of Zero Emission Energy ~, Photoinduced electron-transfer reactions of metal complexes as photosensitizers bound to the active site of enzyme, Poster presentation, 07 Sep. 2021, 07 Sep. 2021, 07 Sep. 2021, rm:research_project_id
  • 柿本 悠奈; 今井 喜胤; 中田 栄司; 高島 弘, 2021年光化学討論会, アントラセン誘導体のシクロデキストリンによる固体状態での包接とその光学特性, Poster presentation, 15 Sep. 2021, 14 Sep. 2021, 16 Sep. 2021
  • 横山理沙; 今井 喜胤; 中田 栄司; 高島 弘, 第31回基礎有機化学討論会, キモトリプシン活性中心へのピレン分子の導入とその光特性, Poster presentation, 21 Sep. 2021, 21 Sep. 2021, 23 Sep. 2021
  • 江口詩織; 今井 喜胤; 中田 栄司; 高島 弘, 第31回基礎有機化学討論会, 水中における疎水性ピレン誘導体/γ-シクロデキストリン錯体の円偏光発光特性, Poster presentation, 21 Sep. 2021, 21 Sep. 2021, 23 Sep. 2021
  • 山下友希; 高島弘, 日本化学会第102春季年会, ビス-1,8-ナフタルイミド誘導体の合成と分子内エキシマー発光特性, Poster presentation, 23 Mar. 2022, 23 Mar. 2022, 26 Mar. 2022
  • 高島弘; 柿本悠奈; 池村 僚矢; 今井喜胤; 藤内謙光; 山崎祥子; 中田栄司, 第19回 ホスト-ゲスト・超分子化学シンポジウム, アントラセン誘導体とγ-シクロデキストリンの固体状態での複合化と円偏光発光特性, 05 Jun. 2022, 04 Jun. 2022, 05 Jun. 2022, rm:research_project_id;rm:research_project_id
  • Hiroshi Takashima; Shiori Eguchi; Risa Yokoyama; Eiji Nakata, The 13th International Symposium of Advanced Energy Science -Research Activities on Zero-Emission Energy Network-, Photoinduced electron-transfer reactions of photosensitizers bound to the active site of enzyme, 06 Sep. 2022, 05 Sep. 2022, 06 Sep. 2022, rm:research_project_id
  • 高島 弘; 柿本 悠奈; 池村 僚矢; 今井 喜胤; 藤内 謙光; 山崎 祥子; 中田 栄司, 2022年光化学討論会, アントラセン誘導体とγ-シクロデキストリンの固体状態での複合化と光学特性, 15 Sep. 2022, 13 Sep. 2022, 15 Sep. 2022
  • 江口詩織; 今井喜胤; 中田栄司; 高島弘, 第32回基礎有機化学討論会, 光学活性なビス1,8-ナフタルイミド誘導体の合成とその円偏光発光特性, 21 Sep. 2022, 20 Sep. 2022, 22 Sep. 2022
  • 高島弘; 横山理沙; 中田栄司, 錯体化学会第72回討論会, 活性中心へ光増感分子を導入したキモトリプシンの発光および光電子移動反応特性, 26 Sep. 2022, 26 Sep. 2022, 28 Sep. 2022, rm:research_project_id;rm:research_project_id;rm:research_project_id
  • 王 智超; 山崎祥子; 森本 積; 大塲美穂; 高島 弘; 小川昭弥, 第32回基礎有機化学討論会, 分子内Diels-Alder反応による修飾ナフタレン誘導体の合成; 反応機構と生成物の物性, 20 Sep. 2022, 20 Sep. 2022, 22 Sep. 2022
  • 王智超; 山崎祥子; 森本積; 大塲美穂; 高島弘; 小川昭弥, 第51回複素環化学討論会, α-ブロモスチレン修飾フマル酸アミドの分子内Diels-Alder反応を利用したナフタレン誘導体の合成, 15 Sep. 2022, 15 Sep. 2022, 17 Sep. 2022

Works

  • 酵素活性中心に導入した光増感金属錯体の光誘起電子移動反応, Apr. 2017, Mar. 2021, rm:research_project_id
  • 金属錯体-酵素複合体のMALDI-TOF-MS質量分析, Oct. 2016
  • タンパク質を用いる円偏光発光システムの構築, Apr. 2016
  • 金属錯体-酵素複合体のMALDI-TOF-MS質量分析, Apr. 2015, Apr. 2015
  • 再構成ヘムタンパク質の新規光触媒機能発現に関する研究, Apr. 2008, Mar. 2014
  • 発光性金属錯体および配位子のDFT計算, Apr. 2013
  • 発光性金属錯体および配位子のDFT計算, 2006, 2013
  • 金属蛋白質複合体の結晶化および構造解析, Oct. 2009, Mar. 2011
  • 光学活性有機電子キャリアーの合成と機能評価, Jun. 2006, Dec. 2009
  • 化学修飾金属蛋白質の光電子移動を利用した蛍光生CO2センサ素子の開発, Jul. 2008, Mar. 2009
  • 化学修飾ヘムタンパク質の光ダイナミックスに関する研究, Dec. 2006, Mar. 2007
  • 超高速時間分解測定を用いた化学修飾タンパク質の光誘起電子移動反応解析, Apr. 2004, Dec. 2006
  • 金属配位化合物・酸化還元有機化合物のX線結晶構造解析, Apr. 2003

Awards

  • 日本化学会BCSJ賞, 日本化学会, Jul. 2003

Research Projects

  • 企画研究, Apr. 2021, Mar. 2022, Principal investigator, 酵素活性中心に導入した光増感金属錯体の光誘起電子移動反応, 高島 弘, 京都大学, 2021年度 共同利用・共同研究, 京都大学エネルギー理工学研究所, rm:published_papers;rm:presentations
  • Apr. 2021, Mar. 2022, Principal investigator, 人工蛋白質複合体内部空間の光電子伝達反応を利用するラジカル中間体生成とその光化学反応系の創製, 高島 弘, 公益財団法人 村田学術振興財団, 第37回(2021年度)研究助成, 奈良女子大学, rm:published_papers;rm:published_papers
  • Apr. 2021, Mar. 2022, Principal investigator, 発光性化合物の合成とその構造解析に関する研究, 高島 弘, 大阪大学大学院工学研究科
  • Apr. 2022, Mar. 2023, Principal investigator, 光増感金属錯体を導入した人工蛋白質内での安定なチロシンラジカル生成とその光エネルギー変換反応系の創製, 公益財団法人 池谷科学技術振興財団, 単年度研究助成, 奈良女子大学, rm:presentations
  • Apr. 2021, Mar. 2022, Principal investigator, 発光性化合物の合成とその構造解析に関する研究, 高島 弘, 大阪大学大学院工学研究科
  • 企画研究, Apr. 2021, Mar. 2022, Principal investigator, 酵素活性中心に導入した光増感金属錯体の光誘起電子移動反応, 高島 弘, 京都大学, 2021年度 共同利用・共同研究, 京都大学エネルギー理工学研究所, rm:published_papers;rm:presentations
  • Apr. 2021, Mar. 2022, Principal investigator, 人工蛋白質複合体内部空間の光電子伝達反応を利用するラジカル中間体生成とその光化学反応系の創製, 高島 弘, 公益財団法人 村田学術振興財団, 第37回(2021年度)研究助成, 奈良女子大学, rm:published_papers;rm:published_papers
  • 一般研究, Jul. 2021, Mar. 2022, Principal investigator, 膵液中の異常タンパク質を光らせて高感度に検知させるエキシマー発光分子の創製, 高島 弘, Nara Women's University, Nara Women's University Intramural Grant for Project Research, Nara Women's University
  • Nov. 2021, Nov. 2022, Principal investigator, 人工蛋白質複合体内部空間の光電子移動反応を利用するチロシンラジカル生成とその光化学反応, 高島 弘, 公益財団法人 住友財団, 基礎科学研究助成, 奈良女子大学, rm:published_papers;rm:published_papers;rm:presentations;rm:presentations
  • Grant-in-Aid for Scientific Research (C), Apr. 2020, Mar. 2023, 20K05567, Principal investigator, 光増感金属錯体を導入した人工蛋白質複合体内チロシンラジカル生成と化学反応系の創製, 高島 弘, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nara Women's University, 4420000, 3400000, 1020000, rm:published_papers;rm:published_papers;rm:published_papers;rm:published_papers;rm:presentations;rm:presentations
  • 一般研究, Jul. 2020, Mar. 2021, Principal investigator, 固体で混ぜてこすると色が変わるシクロデキストリン超分子材料の創製と光学特性, 高島 弘, Nara Women's University, Nara Women's University Intramural Grant for Project Research, Nara Women's University
  • 企画研究, Apr. 2020, Mar. 2021, Principal investigator, 酵素活性中心に導入した光増感金属錯体の光誘起電子移動反応, 高島 弘, 京都大学, 2020年度共同利用・共同研究, 京都大学エネルギー理工学研究所, rm:published_papers;rm:presentations;rm:presentations;rm:works
  • 企画研究, Apr. 2019, Mar. 2020, Principal investigator, 酵素活性中心に導入した光増感金属錯体の光誘起電子移動反応, 高島 弘, 京都大学, 平成31年度共同利用・共同研究, 京都大学エネルギー理工学研究所
  • 企画研究, Apr. 2018, Mar. 2019, Principal investigator, 酵素活性中心に導入した光増感金属錯体の光誘起電子移動反応, 高島 弘, 京都大学, 平成30年度共同利用・共同研究, 京都大学エネルギー理工学研究所
  • 企画研究, Apr. 2017, Mar. 2018, Principal investigator, 酵素活性中心に導入した光増感金属錯体の光誘起電子移動反応, 高島 弘, 京都大学, 平成29年度共同利用・共同研究, 京都大学エネルギー理工学研究所, rm:presentations
  • Grant-in-Aid for Scientific Research (C), Apr. 2012, Mar. 2015, 24550078, Principal investigator, Photoinduced electron- and energy-transfer reactions of protein-photosensitizer complexes, HIROSHI TAKASHIMA, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nara Women's University, 5460000, 4200000, 1260000, By using preferential enzyme-inhibitor interactions, we study the photophysical properties of artificial Carbonic Anhydrase or Chymotrypsin-[Ru(bpy)3]2+ type complex and the detailed photoinduced electron- or energy-transfer mechanisms are discussed. For example, we prepared a Ru(II)-based CA inhibitor,tethering a benzenesulfonamide group and a [Ru(bpy)3]2+ moiety and constructed the artificial CA-Ru(II) complex. After steady-state photoirradiation, the photo-excited triplet state of Ru(II)* was quenched by a sacrificial quencher through an intermolecular photoinduced ET mechanism, giving the oxidized Ru(III) complex. The following intramolecular electron abstraction from an amino-acid residue near the active site of CA proceeded. On the other hand, several types of the [Ru(bpy)2(L)]2+ complexes were synthesized and their electrochemical and spectral properties were examined. Spin densities were analyzed to characterize triplet states in those complexes.
  • シーズ発掘試験, Apr. 2008, Mar. 2009, Principal investigator, 化学修飾金属蛋白質の光電子移動を利用した蛍光性CO2センサ素子の開発, 高島 弘, 科学技術振興機構(JST), 地域イノベーション創出総合支援事業 重点地域研究開発推進プログラム, 奈良女子大学
  • Grant-in-Aid for Scientific Research (C), 2007, 2008, 19550064, PHOTOINDUCED ELECTRON TRANSFER OF METAL COMPLEXES AND CHEMICALLY MODIFIED METALLOPROTEINS, TSUKAHARA Keiichi; TAKASHIMA Hiroshi, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nara Women's University, 4680000, 3600000, 1080000, 本研究では、光機能素子としての亜鉛ポルフィリンやルテニウム(II)・イリジウム(III)錯体及び電子伝達可能なビオローゲン・アクリジン等の有機化合物の複合体を合成・開発し、これらを材料としてミオグロビンやカルボニックアンヒドラーゼ等の金属蛋白質へ組み入れた半人工蛋白質を合成した。また、これらの複合体をDNAに組み入れた超分子複合体の構築に成功し、光電子移動反応及びエネルギー移動反応機構を解明した。
  • Grant-in-Aid for Young Scientists (B), 2002, 2004, 14750697, Principal investigator, 化学修飾法と再構成法を利用したヘム蛋白質複合化手法の開発と光機能化, 高島 弘, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Nara Women's University, 2500000, 2500000, 生体内におけるDNA中のチミン二量体の光修復に関しては、DNAフォトライアーゼがその機能を担っている。昨年、DNAフォトライアーゼ-DNA複合体のX線結晶構造解析が報告され、非常に注目を集めている。本研究では、DNAに対するインターフェースをヘム蛋白質に化学的に導入することにより、新規なヘム蛋白質-DNA複合体を構築し、DNAを反応場とした光機能化を目指すことを目的としている。本研究課題に対して我々は、DNA結合能を示すヘム蛋白質の調製のため、種々のインターフェースを有する補因子ヘムの合成や、リシン側鎖へ簡便に導入できる修飾試薬の合成を行った。インターフェースのとしては、平面型白金(II)錯体、エチジウム、アクリジンに代表されるインターカレーター類を取り上げた。これらインターカレーターを修飾した化学修飾ヘム蛋白質(ミオグロビンやシトクロムc)の合成に成功した。得られたヘム蛋白質は、UV、蛍光、CDスペクトルなどから、天然型ヘム蛋白質と同様に、その構造を安定に保持したまま溶液内で存在可能であることが明らかとなった。 本研究課題において調製した、アクリジン修飾ミオグロビンについては、補因子として亜鉛ポルフィリンを用いた場合、アクリジンの光励起によって亜鉛ポルフィリンへの分子内エネルギー移動が、ヘムを用いた場合、アクリジンからヘムへの分子内電子移動消光反応が観測された。このアクリジン修飾ミオグロビンは、DNAと複合体を形成し、後者では消光されていたアクリジンの蛍光が回復する過程を、蛍光スペクトルによって確認することに成功した。またインターカレーターである平面型白金(II)錯体を修飾したシトクロムcでは、その修飾個数ごとに容易に分離精製が可能であることがわかり、現在修飾位置の決定およびDNAとの複合体形成を試みている。
  • Grant-in-Aid for Scientific Research on Priority Areas, 2002, 2002, 14050067, 化学修飾ヘム蛋白質の光誘起電子移動反応, 塚原 敬一; 高島 弘, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas, Nara Women's University, 2300000, 2300000, 1.ジエチレントリアミン五酢酸イオン(DTPA)を化学修飾したミオグロビン(M^MbDTPA, M^=Zn, Fe)のDTPA部分に金属イオンを導入したミオグロビン・金属錯体複合体(M^Mb{M^dtpa)}, M^=Zn, Fe ; M^=Co)及びシトクロムcの量子移動反応経路の検討 N-末端グリシンを化学修飾したミオグロピン(M^Mb{Co^(dtpa)}(Glyl), M^=Zn, Fe))におけるZnMbの光励起三重項状態から{Co^(dtpa)}への電子移動消光反応及びFe^Mbから{Co^(dtpa)}への電子移動反応経路を検討した。その結果,いずれも同じ反応経路(Heme→Phe138→Leu137→{Co^(dtpa)}(Glyl),18.8Å)で進行していることがわかった。また,シトクロムcのLys13に化学修飾したcytc^{Co^(dtpa)}(Lys13)のFe^から{Co^(dtpa)}への電子移動反応はthrough bond(Heme→Cys14→{Co^(dtpa)}(Lys13),18.6Å)で進行することが示唆された。 2.亜鉛ミオグロビンの光学活性ビオローゲン及びキノリニウムイオンによる電子移動消光反応及び逆電子移動反応における立体選択性の検討 光学活性なビナフチル基を持つ4,4'-ビピリジニウムイオン(ビオローゲン,BNMV^<4+>)及びキノリニウムイオン(PMQ^+, PQ^+)による立体選択的電子移動消光反応及び逆電子移動反応を検討した。特に,ZnMb^<・+>とBNMV^<・3+>との逆電子移動反応では顕著な立体選択性が見いだされた。また,ZnMbの電子移動反応では蛋白質のコンフォメーション変化が律速段階に関与していることが示唆されているが,キノリニウムイオンの場合は電子移動律速であることを,今回,初めて見いだした。 3.インターカレーターを持つ半人工ミオグロビンやシトクロムcとDNAとの複合体の構築 インターカレーターとしてエチジウムイオンを共有結合させたミオグロビン及びシトクロムcを調製し,エチジウムイオンの蛍光のヘムによる消光反応を検討した。また,修飾ヘムによる再構成ミオグロビンの調製のため,アクリジンやシスプラチン錯体を結合させたヘム及び亜鉛ポルフィリンを合成した。今後,DNAとの相互作用及び光誘起電子移動反応を検討する予定である。
  • 化学修飾金属タンパク質・金属配位化合物の高速光ダイナミックス, 0, 0, 0, Competitive research funding
  • 機能性金属タンパク質のデザイン, 0, 0, 0, Competitive research funding
  • 酸化還元活性な有機・無機化合物の合成と、その光電子移動反応解析, 0, 0, 0, Competitive research funding
  • 光学活性有機電子キャリアーの開発と機能評価, 0, 0, 0, Competitive research funding
  • 化学修飾金属タンパク質の超高速光ダイナミックス, 0, 0, 0, Competitive research funding
  • 光機能性金属錯体の合成と性質, 0, 0, 0, Competitive research funding
  • 金属タンパク質の設計と光誘起電子移動反応, 0, 0, 0, Competitive research funding
  • Photo induced electron transfer reactions in the metalloprotein, 0, 0, 0, Competitive research funding
  • 企画研究, Apr. 2022, Mar. 2023, Principal investigator, 酵素活性中心への光増感分子の導入による酵素複合体内光誘起電子移動反応, 高島弘, 京都大学, 2022年度 共同利用・共同研究, 京都大学エネルギー理工学研究所, rm:presentations
  • Apr. 2022, Mar. 2023, Principal investigator, 光増感金属錯体を導入した人工蛋白質内での安定なチロシンラジカル生成とその光エネルギー変換反応系の創製, 公益財団法人 池谷科学技術振興財団, 単年度研究助成, 奈良女子大学
  • Apr. 2022, Mar. 2023, Principal investigator, 光増感剤を導入した人工蛋白質複合体内チロシンラジカル生成による光エネルギー変換反応系の創製, 公益財団法人 高橋産業経済研究財団, 研究助成, 奈良女子大学, rm:presentations

Ⅲ.社会連携活動実績

1.公的団体の委員等(審議会、国家試験委員、他大学評価委員,科研費審査委員等)

  • 日本化学会 近畿支部, 化学教育協議会委員, Mar. 2015, 9999, Society
  • Mar. 2013, Feb. 2015, Society
  • Society
  • Mar. 2015, 9999


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