1998 Fiscal Year Final Research Report Summary
Creation of Substitution Labile Pyrazolylborate Metal Complexes
| Project/Area Number |
09640675
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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 | CHUO UNIVERSITY |
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Principal Investigator |
YAMAZAKI Hiroshi Chuo University, Department of Applied Chemica, Professor, 理工学部, 教授 (00087511)
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| Project Period (FY) |
1997 – 1998
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| Keywords | pyrazolylborate Metal Complex / agostic interaction / X ray crystallographic analysis / cobalt / nickel / ruthenium / rhodium / palladium |
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| Research Abstract |
(1) Bis[dihydrobis(3,5-bis(trifluoromethyl)pyrazolyl)borate]cobalt was prepared and the structure was determined by X ray crystallographic analysis. The cobalt center is coordinated to four pyrazolyl groups in a square planner manner and to two B-H groups at the axial positions forming totally a distorted octahedral configuration. This is in marked contrast to those of known non-substituted and 3, 5-dimethyl substituted pyrazolylborate derivatives which appear inn a tetrahedral configuration Similar nickel complex having a B-H-M agostic interaction was prepared.
(2) Bis(triphenylphosphine)[dihydrobis(3,5-R_2-pyrazolyl)borate]ruthenium hydrides (R=H, Me, CF_3) were prepared and the structures containing a B-H-Ru agostic interaction were determined by X ray crystallography. Based on the reactivity with CO, strength of the agostic interaction was estimated to decrease in the order, Me> H * CF_3.
(3) Bis(triphenylphosphine)[dihydrobis(3, 5-R_2-pyrazolyl)borate]rhodium complexes (R=H, Me, CF_3) were prepared and the structures were determined by X ray crystallographic analysis. The rhodium centers are coordinated in a square planner manner to the four pyrazolyl groups. No B-H-Rh agostic interactions were observed in these complexes.
(4) eta^3-Allyl and indenyl[hydrotris(3,5-R_2-pyrazolyl)borate]palladium complexes (R=H, Me, CF_3) were prepared and the structures were determined by X ray crystallographic analysis. Their fluxional behavior in solution were studied by NMR spectroscopy.
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