| Project/Area Number |
09640661
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Inorganic chemistry
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| Research Institution | Gifu University |
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Principal Investigator |
EBIHARA Masahiro Faculty of Engineering, Gifu University Associate Professor, 工学部, 助教授 (80201961)
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| Co-Investigator(Kenkyū-buntansha) |
TSUJI Yasushi Hokkaido Univ., Catalysis Research Center Professor, 触媒化学研究センター, 教授 (30144330)
KAWAMURA Takashi Faculty of Engineering, Gifu University Professor, 工学部, 教授 (40026125)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1998: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1997: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | cluster complex / cationic radical / silver / crystal structure / paramagnetic shift / cobalt / metal-metal bond / halogen / イオンラジカル / 結果構造 / 不対電子分布 |
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| Research Abstract |
Reaction of [Co_3Cp_3 (mu_3-CPh)_2] (1) with the salts of strongly-coordinating anions (CF_3CO_2-, NO_3-) gives silver (I) adducts of 1, [Co_3Cp_3(mu_3-CPh)_2{muAg(X)}] (X= CF_3CO_2- (2), NO_3- (3)). The Co-Co bonds bridged by the Ag atom are longer than that of 1 (2.38). ^1HNMR spectra of 2 and 3 in CD_2Cl_2 indicates partial dissociation of the AgX group. The ^1H NMR spectra of CD_3CN solutions and the ESR spectra in frozen CH_3CN solutions of 2 and 3 shows generation of 1^+ without deposition of Ag metal. It suggests that equilibrium of Ag^+ and 1 with Ag^0 and 1^+ is established in acetonitrile.
Reaction of I with halogens (X_2 = Cl_2, Br_2, I_2) in CH_2Cl_2 gives halogen-bridged complex {Co_3Cp_3(mu_3-CPh)_2(mu-X)]^+. The halogen-bridged Co-Co distance is elongated and the Co-Co distances without halogen-bridge remaine unchanged from that of 1 (2.38"A"). Cyclic voltammogram of [Co_3Cp_3(mu_3-CPh)_2(mu-Cl)]PF_6 in CH_3CN with 0.1 M n-Bu_4NPF_6 as supporting electrolyte shows an irreversible reduction wave (-0.49 V vs Fc/Fc^+). The irreversible reduction causes recovery of 1. To examine the mechanism of formation of the halogen-bridged complex, cyclic voltammetry of 1 in 0.1 M n-Bu_4NC]/CH_3CN is carried out. At 100 mVs^<-1> scan rate the irreversible oxidation waveis observed at the same Epa value as the quasi-reversible oxidation of 1 in 0.1 Mn-Bu_4NPF_4/CH_3CN.The current value of the wave is 1.3 times bigger than that in 0.1 M n-Bu_4NPF_6/CH_3CN and a new irreversible reduction peak is appeared at -0.46 V vs Fc/Fc^+ that is corresponding to reduction of [Co_3Cp_3(mu_3-CPh)_2(mu-Cl)]^+. When the scan speed is 500 mVs^<-1>, the current value of the oxidation peak is very similar to that in 0.1 M n-Bu_4NPF_6/CH_3CN and the small reduction peak at -0.09 V vs Fc/Fc^+ which was due to the reduction of [Co_3Cp_3(mu_3-CPh)_2]^+. It indicated that the oxidation of 1 follows coordination of Cl^- and immediate oxidation to 2^+.
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