| 1. |
A Wada, S Ogo, Y Watanabe, K Jitsukawa, H Masuda, H Einaga, Novel non-heme iron complexes as oxidation catalysts in alkene functionarlization, JOURNAL OF INORGANIC BIOCHEMISTRY, Vol.74, No.1-4, p.331, 1999.04. |
| 2. |
T Funabiki, T Ito, H Matsui, A Fukui, M Aki, S Ogo, Y Watanabe, Formation of a manganese(II)-semiquinonate complex and the selective intradiol cleavage with molecular oxygen in relevance to manganese-catechol dioxygenases, JOURNAL OF INORGANIC BIOCHEMISTRY, Vol.74, No.1-4, p.133, 1999.04. |
| 3. |
S Ogo, R Yamahara, M Roach, T Suenobu, M Aki, T Ogura, T Kitagawa, H Masuda, S Fukuzumi, Y Watanabe, Structural and spectroscopic features of a cis (hydroxo)-Fe-III-(carboxylato) configuration as an active site model for lipoxygenases, INORGANIC CHEMISTRY, 10.1021/ic0200040, Vol.41, No.21, pp.5513-5520, 2002.10, In our preliminary communication (Ogo, S.; Wada, S.; Watanabe, Y.; Iwase, M.; Wada, A.; Harata, M.; Jitsukawa, K.; Masuda, H.; Einaga, H. Angew. Chem., Int. Ed. 1998, 37, 2102-2104), we reported the first example of X-ray analysis of a mononuclear six-coordinate (hydroxo)iron(III) non-heme complex, [Fe-III(tnpa)(OH)(RCO2)]ClO4 [tnpa = tris(6-neopentylamino-2-pyridylmethyl)amine; for 1, R = C6H5], which has a characteristic cis (hydroxo)Fe-III-(carboxylato) configuration that models the cis (hydroxo)-Fe-III-(carboxylato) moiety of the proposed (hydroxo)iron(III) species of lipoxygenases. In this full account, we report structural and spectroscopic characterization of the cis (hydroxo)-Fe-III-(carboxylato) configuration by extending the model complexes from 1 to [Fe-III(tnpa)(OH)(RCO2)]ClO4 (2, R = CH3; 3, R = H) whose cis (hydroxo)-Fe-III-(carboxylato) moieties are isotopically labeled by (OH-)-O-18, (OD-)-O-16, (OD-)-O-18, (CH3CO2-)-C-12-C-12-O-18, (CH3CO2-)-C-12-C-13-O-16, (CH3CO2-)-C-13-C-12-O-16, (CH3CO2-)-C-13-C-13-O-16, and (HCO2-)-C-13-O-16. Complexes 1-3 are characterized by X-ray analysis, IR, EPR, and UV-vis spectroscopy, and electrospray ionization mass spectrometry (ESI-MS).. |
| 4. |
T Abura, S Ogo, Y Watanabe, S Fukuzumi, Isolation and crystal structure of a water-soluble iridium hydride: A robust and highly active catalyst for acid-catalyzed transfer hydrogenations of carbonyl compounds in acidic media, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/ja0288237, Vol.125, No.14, pp.4149-4154, 2003.04, This paper reports the isolation and structural determination of a water-soluble hydride complex [Cp*Ir-III(bpy)H](+) (1, Cp* = eta(5)-C5Me5, bpy = 2,2'-bipyridine) that serves as a robust and highly active catalyst for acid-catalyzed transfer hydrogenations of carbonyl compounds at pH 2.0-3.0 at 70 degreesC. The catalyst 1 was synthesized from the reaction of a precatalyst [Cp*Ir-III (bpy) (OH2)](2+) (2) with hydrogen donors HCOOX (X = H or Na) in H2O under controlled conditions (2.0 < pH < 6.0, 25 degreesC) which avoid protonation of the hydrido ligand of 1 below pH ca. 1.0 and deprotonation of the aqua ligand of 2 above pH ca. 6.0 (pK(a) value of 2 = 6.6). X-ray analysis shows that complex 1 adopts a distorted octahedral geometry with the Ir atom coordinated by one eta(5)-Cp*, one bidentate bpy, and one terminal hydrido ligand that occupies a bond position. The isolation of 1 allowed us to investigate the robust ability of 1 in acidic media and reducing ability of 1 in the reaction with carbonyl compounds under both stoichiometric and catalytic conditions. The rate of the acid-catalyzed transfer hydrogenation is drastically dependent on pH of the solution, reaction temperature, and concentration of HCOOH. The effect of pH on the rate of the transfer hydrogenation is rationalized by the pH-dependent formation of 1 and activation process of the carbonyl compounds by protons. High turnover frequencies of the acid-catalyzed transfer hydrogenations at pH 2.0-3.0 are ascribed not only to nucleophilicity of 1 toward the carbonyl groups activated by protons but also to a protonic character of the hydrido ligand of 1 that inhibits the protonation of the hydrido ligand.. |
| 5. |
湯浅 順平, 末延 知義, 小江 誠司, 福住 俊一, 希土類イオン架橋型錯体生成による高次自己組織化電子移動反応, 希土類 = Rare earths, Vol.44, pp.208-209, 2004.05. |
| 6. |
S Ogo, K Uehara, T Abura, Y Watanabe, S Fukuzumi, pH-selective synthesis and structures of alkynyl, acyl, and ketonyl intermediates in anti-Markovnikov and Markovnikov hydrations of a terminal alkyne with a water-soluble iridium aqua complex in water, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/ja0473541, Vol.126, No.50, pp.16520-16527, 2004.12, Chemoselective synthesis and isolation of alkynyl [Cp*Ir-III(bpy)CCPh](+) (2, Cp* = eta(5)-C5Me5, bpy = 2,2'-bipyridine), acyl [Cp*Ir-III(bpy)C(O)CH2Ph](+) (3), and ketonyl [Cp*Ir-III(bpy)CH2C(O)Ph](+) (4) intermediates in anti-Markovnikov and Markovnikov hydration of phenylacetylene in water have been achieved by changing the pH of the solution of a water-soluble aqua complex [Cp*Ir-III(bpy)(H2O)](2+) (1) used as the same starting complex. The alkynyl complex [2](2).SO4 was synthesized at pH 8 in the reaction Of 1.SO4 with H2O at 25 degreesC, and was isolated as a yellow powder of 2.X (X = CF3SO3 or PF6) by exchanging the counteranion at pH 8. The acyl complex [3](2).SO4 was synthesized by changing the pH of the aqueous solution of [2](2).SO4 from 8 to 1 at 25 degreesC, and was isolated as a red powder of 3.PF6 by exchanging the counteranion at pH 1. The hydration of phenylacetylene with 1.SO4 at pH 4 at 25 degreesC gave a mixture of [2](2).SO4 and [4](2).SO4. After the counteranion was exchanged from SO42- to CF3SO3-, the ketonyl complex 4.CF3SO3 was separated from the mixture of 2.CF3SO3 and 4.CF3SO3 because of the difference in solubility at pH 4 in water. The structures of 2-4 were established by IR with C-13-labeled phenylacetylene (Ph(12)Cdrop(13)CH), electrospray ionization mass spectrometry (ESI-MS), and NMR studies including H-1, C-13, distortionless enhancement by polarization transfer (DEPT), and correlation spectroscopy (COSY) experiments. The structures of 2.PF6 and 3.PF6 were unequivocally determined by X-ray analysis. Protonation of 3 and 4 gave an aldehyde (phenylacetaldehyde) and a ketone (acetophenone), respectively. Mechanism of the pH-selective anti-Markovnikov vs Markovnikov hydration has been discussed based on the effect of pH on the formation of 2-4. The origins of the alkynyl, acyl, and ketonyl ligands of 2-4 were determined by isotopic labeling experiments with D2O and (H2O)-O-18.. |
| 7. |
S Ogo, B Kure, H Nakai, Y Watanabe, S Fukuzumi, Why do nitrogenases waste electrons by evolving dihydrogen?, APPLIED ORGANOMETALLIC CHEMISTRY, 10.1002/aoc.744, Vol.18, No.11, pp.589-594, 2004.11, In nature, nitrogen is commonly fixed as the most reduced form, ammonia (NH3) and as the most oxidized form, i.e. nitrate ion (NO3-). Nitrogenases catalyze the reduction of N-2 into NH3 by using protons and electrons with evolution of H-2. However, the reason why the enzymes waste electrons by evolving H-2 has yet to be clarified. We have previously reported (J. Am. Chem. Soc. 2002; 124: 597) pH-dependent heterolytic cleavage of H-2 and subsequent reduction of NO3- with evolution of H-2 by iridium complexes in water. We propose herein a catalytic mechanism of nitrogenases, which can account for evolution of H-2 in the reduction of N-2 to NH3 in relation to a mechanism of the reduction of NO3-. Copyright (C) 2004 John Wiley Sons, Ltd.. |
| 8. |
H Hayashi, H Nishida, S Ogo, S Fukuzumi, Synthesis and crystal structures of water-soluble rhodium(III) complexes with 1,4,7-triazacyclononane and 2,2 '-bipyridine supporting ligands, INORGANICA CHIMICA ACTA, 10.1016/j.ica.2004.03.001, Vol.357, No.10, pp.2939-2944, 2004.07, New water-soluble rhodium(III) complexes with a tacn (1,4,7-triazacyclononane) and a bpy (2,2'-bipyridine) supporting ligands were synthesized. The reaction of [Rh-III(tacn)Cl-3] (1) with equimolar amount of bpy and two equivalents of AgNO3 in H2O at reflux for 10 h gave a water-soluble chloro complex [Rh-III(tacn)(bpy)Cl](NO3)(2) {2(NO3)(2)}. Complex 2(NO3)(2) was treated with equimolar amount of AgNO3 in H2O at reflux for 10 h to give a water-soluble nitrato complex [Rh-III(tacn)(bpy)(NO3)](NO3)(2) {3(NO3)(2)}. Water-solubility of 3 with NO3- ligand (46.5 mg/mL) is high compared with that of 2 with Cl- ligand (14.5 mg/mL) under the same conditions (at pH 7.0 at 25 degreesC). The structures of 2 and 3 were unequivocally determined by X-ray analysis. Their structures in H2O were also examined by H-1 NMR, IR, and electrospray ionization mass spectrometry (ESI-MS). (C) 2004 Elsevier B.V. All rights reserved.. |
| 9. |
S Fukuzumi, H Kotani, K Ohkubo, S Ogo, NV Tkachenko, H Lemmetyinen, Electron-transfer state of 9-mesityl-10-methylacridinium ion with a much longer lifetime and higher energy than that of the natural photosynthetic reaction center, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/ja038656q, Vol.126, No.6, pp.1600-1601, 2004.02. |
| 10. |
S Ogo, K Uehara, T Abura, Y Watanabe, S Fukuzumi, Aqueous polymerization of styrene promoted by water-soluble robust ruthenium hydride complexes, ORGANOMETALLICS, 10.1021/om034335b, Vol.23, No.12, pp.3047-3052, 2004.06, Aqueous polymerization of styrene in biphasic media (styrene/water) has been achieved by water-soluble robust mononuclear hydride complexes [(eta(6)-C6Me6)Ru-II(bpy)H](n)(X) {[1](eta)(X), where X = SO4 (n = 2) or CF3SO3 (n = 1), bpy = 2,2'-bipyridine}. The hydride complex [1](2)(SO4) was synthesized from the reaction of an aqua complex [(eta(6)-C6Me6)Ru-II(bpy)(H2O)]SO4) {2(SO4)} with a water-soluble hydrogen donor HCOONa in H2O in a pH range of 4-12 at 70-100degreesC. The structures Of [1](2)(SO4) and 1(CF3SO3) were determined by X-ray analysis, H-1 and H-2 NMR, IR, and electrospray ionization mass spectrometry (ESI-MS). X-ray analysis has revealed that complex 1(CF3SO3) adopts a distorted octahedral geometry with the Ru atom coordinated by one eta(6)-C6Me6 ligand, one bidentate bpy ligand, and one terminal hydrido ligand that occupies a bond position. Complex [1](2)(SO4) reacts with excess amounts of styrene in biphasic media to provide polystyrene in a 62% isolated yield for 8 h. The polydispersity (M-w/M-n) of the obtained polystyrene is 1.8. The isolated yield of polystyrene shows a maximum around pH 8. The pH-dependence is similar to the pH-dependent formation of 1. Growing polymer intermediates [(C6Me6)Ru(bpy) {(C2H3)(C6H5)}(n)H](+) (n = 1-4) were directly observed by ESI-MS.. |
| 11. |
H Kitaguchi, K Ohkubo, S Ogo, S Fukuzumi, Direct ESR detection of pentadienyl radicals and peroxyl radicals in lipid peroxidation: Mechanistic insight into regioselective oxygenation in lipoxygenases, JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 10.1021/ja044345j, Vol.127, No.18, pp.6605-6609, 2005.05, Well-resolved ESR spectra of free pentadienyl radicals have been observed under photoirradiation of di-tert-butylperoxide ((BuOOBut)-O-t) and polyunsaturated fatty acids in the absence Of O-2, allowing us to determine the hfc values. The hfc values of linoleyl radical indicate that the spin density is the largest at the C-11 position. The linoleyl radical is readily trapped by O-2 to produce the peroxyl radical (11-HPO center dot) in which O-2 is added mainly at the C-11 position of the pentadienyl radical as indicated by the comparison of the ESR spectra of peroxyl radicals derived from linoleic acid and [11,11-H-2(2)]linoleic acid. The peroxyl radical (13-HPO center dot), which is initially formed by the hydrogen abstraction from 13-(S)-hydroperoxy-9(2),11(E)-octadecadienoic acid (13-HPOD) by (BuO center dot)-O-t, is found to isomerize to 11 -HPO center dot via removal Of 02 from 13-HPO center dot and addition Of O-2 to linoleyl radical to produce 11 -HPO center dot. This finding supports an idea Of O-2 entering via a specific protein channel, which determines the stereo- and regiochemistry of the biradical combination between O-2 and linoleyl radical in lipoxygenases.. |
| 12. |
S Ogo, H Hayashi, K Uehara, S Fukuzumi, Crystal structures of organometallic aqua complexes [Cp*Rh-III(bpy)(OH2)](2+) and [Cp*Rh-III(6,6 '-Me(2)bpy)(OH2)](2+) used as key catalysts in regioselective reduction of NAD(+) analogues, APPLIED ORGANOMETALLIC CHEMISTRY, 10.1002/aoc.837, Vol.19, No.5, pp.639-643, 2005.05, Crystal structures of organometallic aqua complexes [Cp*Rh-III(bpy)(OH2)](2+) (1, Cp* = eta(5)-CsMe5, bpy = 2,2'-bipyridine) and [Cp*Rh-III(6,6'-Me(2)bpy)(OH2)](2+) (2, 6,6'-Me(2)bpy = 6,6'-dimethyl-2,2'-bipyridine) used as key catalysts in regioselective reduction of NAD(+) analogues were determined definitely by X-ray analysis. The yellow crystals of 1(PF6)(2) and orange crystals of 2(CF3SO3)(2) used in the X-ray analysis were obtained. from aqueous solutions of 1(PF6)(2) and 2(CF3SO3)(2). The Rh-Oaqua length of 2.194(4) angstrom obtained for 1(PF6)(2) is Significantly different from that of 2.157(3) A obtained for the previously reported disorder model [Cp*Rh-III(bpy)(0.7H(2)O/0.3CH(3)OH)](CF3SO3)(2)center dot 0.7H(2)O in which the coordinated water is replaced by a coordinated methanol. The five-membered ring involving the Rh atom and the 6,6'-Me(2)bpy chelating unit in 2(CF3SO3)(2) is not flat, whereas the five-membered chelate ring in 1(PF6)(2) is nearly flat. Such a non-planar structure in 2(CF3SO3)(2) is ascribed to the steric repulsion between the 6,6'-Me(2)bpy ligand and the Cp* ligand. Copyright (c) 2005 John Wiley C Sons, Ltd.. |
| 13. |
Takuo Minato, Takamasa Teramoto, Yoshimitsu Kakuta, Seiji Ogo, Ki-Seok Yoon, Biochemical and structural characterization of a thermostable Dps protein with His-type ferroxidase centers and outer metal-binding sites., FEBS open bio, 10.1002/2211-5463.12837, Vol.10, No.7, pp.1219-1229, 2020.03, The DNA-binding protein from starved cells (Dps) is found in a wide range of microorganisms, and it has been well characterized. However, little is known about Dps proteins from non-heterocystous filamentous cyanobacteria. In this study, a Dps protein from the thermophilic non-heterocystous filamentous cyanobacterium Thermoleptolyngbya sp. O-77 (TlDps1) was purified and characterized. PAGE and CD analyses of TlDps1 demonstrated that it had higher thermostability than previously reported Dps proteins. X-ray crystallographic analysis revealed that TlDps1 possessed His-type ferroxidase centers within the cavity and unique metal binding sites located on the surface of the protein, which presumably contributed to its exceedingly high thermostability.. |
| 14. |
小江 誠司, 水素からの電子, 學士會会報, 2020.07. |
| 15. |
小江 誠司, 高機能性金属錯体が拓く触媒科学
高機能性金属錯体が拓く触媒科学 （ＣＳＪ：３７）
13章 水素分子の活性化と分子燃料電池, CSJカレントレビュー・日本化学会編, 2020.04. |
| 16. |
松本 崇弘, 小江 誠司, 分子および酵素燃料電池, 化学と工業, 2015.05. |
| 17. |
松本 崇弘, 小江 誠司, 水素が好き？酸素が好き？—天然の酵素を模範とする分子燃料電池の開発, 現代化学, 2013.08. |
| 18. |
松本 崇弘, 小江 誠司, 新しい水素活性化触媒―［ NiFe］ヒドロゲナーゼに学ぶ水素からの電子抽出, 月刊「化学」, 2013.08. |
| 19. |
小江 誠司, 磯邉 清, ヒドロゲナーゼをモデルとした触媒開発, 月刊BIOINDUSTRY, 2013.03. |
| 20. |
小江 誠司, 松本 崇弘, 分子燃料電池, 化学と工業, 2013.02. |
