Grant-in-Aid for international Scientific Research
|Allocation Type||Single-year Grants|
|Research Institution||Tohoku University|
OGINO Hiroshi Faculty of Science, Tohoku University, 理学部, 教授 (00004292)
CERVANTES J. Faculted de Quimica, Universidad Autonoma Metropolitana, メトロポリターナ大学, 教授
SAUVAGE J. -P. Institut de Chimie, Universite Louis Pasteur de Strasbourg, パスツール大学・化学研究所, 教授
BAKAC A. Ames Laboratory, Iowa State University, エームズ研究所, 研究員
ESPENSON J. H. Department of Chemistry, Iowa State University, 教授
上野 圭司 東北大学, 理学部, 助手 (20203458)
飛田 博実 東北大学, 理学部, 助手 (30180160)
下井 守 東北大学, 理学部, 助教授 (30092240)
SIMOI Mamoru Faculty of Science, Tohoku University
UENO Keiji Faculty of Science, Tohoku University
|Project Period (FY)
1989 – 1990
Completed(Fiscal Year 1990)
|Budget Amount *help
¥4,000,000 (Direct Cost : ¥4,000,000)
Fiscal Year 1990 : ¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1989 : ¥2,000,000 (Direct Cost : ¥2,000,000)
|Keywords||photolysis, / silicon-29 NMR, / INEPT-INADEQUATE pulse sequence, / dynamic NMR, / bis (silylene) complex, / bis (germylene) complex, / silylene-bridged complex, / silanetriyl complex|
1. We discovered that the irradiation of various alkoxy-substituted disilanyl (carbonyl) iron or manganese complexes efficiently gives alkoxy-bridged bis (silylene) complexes containing metal-silicon unsaturated bonds. Their unique structural features were revealed by X-ray crystallography. The remarkable down field shift of ^<29>Si NMR signals and some unprecedented reactivities of these products were also found.
2. The ^<29>Si-^<29>Si coupling constants for a bis (silylene) complex and some related silicon compounds were determined by using the INEPT-INADEQUATE pulse sequence. The coupling constants correlate linearly with 3s (Si) -3s (Si) atomic orbital bond populations which were determined by the EHMO calculation.
3. We found that alkoxy-bridged bis (germylene) and silylene (germylene) complexes can also be prepared by the similar photoreaction. Investigation of the dynamic behavior of these complexes by temperature-dependent NMR spectroscopy revealed that the coordination of alkoxy
l group to Ge is weaker than that to Si.
4. We developed a new one-step synthetic method of silylene-bridged diiron complexes Cp_2Fe_2(CO)_3 (mu-SiHR) (R = t-Bu, (CMe_2)_2H) which utilizes the photolysis of CpFe(CO)_2SiMe_3 in the presence of RSiH_3. Furthermore, on the basis of the isolation of the intermediates, we suggested the mechanism of this reaction in which the photochemical dissociation of CO and the oxidative addition and reductive elimination of hydrosilanes are repeated twice.
5. We succeeded to synthesize the first donor-stabilized silanetriyl dinuclear complexes [Cp_2Fe_2(CO)_3(mu-SiBu^t・Donor)]I, and determined their X-ray crystal structures.
6. We found that upon irradiation a disilanylene-bridged diiron complex CpFe(CO)_2-SiMe_2SiMe_2CpFe(CO)_2 first changes to a mixture of the geometric isomers of silylene-bridged diiron complexes, which then change to the geometric isomers of bis (silylene-bridged) diiron complexes with successive loss of CO's. X-ray crystal structure analyses and kinetic studies were carried out on these products. Less