**************** The 9th., Lab Seminar *****************

Date: Thu, October 16, 2003  PM 1:00-

Place: No.616 Seminar room
　　　　　　 Graduate School of Information Science

Speaker: Yusuke Ohta

Title: The Carbon-Lithium Electron Pair Bond in (CH3Li)n (n = 1, 2, 4)
　　　　　（F. M. Bickelhaupt, N. J. R. van E. Hommes, C. F. Guerra and E.
J. Baerends Organometallics 1996, 15, 2923-2931）

Abstract: 
 Modern ab initio quantum chemical studies have been provided a largely
ionic of the carbon-lithium bond. In the population analysis methods, yield
lithium atomic charges between +0.75 and +0.90e. Thus, organolithium
oligomers (RLi)n can be considered as aggregates of lithium cations and
carbanions.
 In this paper, authors discuss CH3Li, (CH3Li)2, (CH3Li)4 using
DFT(density-functional theory) and ab initio method. The purpose is to
clarify some points concerning the bonding in organolithium oligomers. In
paticular, they wish to obtain a better understanding of the nature of the
carbon-lithium bond in these compounds.To what extent can it be conceived as
a polar C-Li electron pair bond? Does it contain distinct covalent
components? What is the role of the Li 2p orbitals, and what is the
electronic structure of the (Li)n cores? To answer these question, a
detailed
analysis of the bonding mechanisms between the (CH3・)n and (Li・)n
fragments in (CH3Li)n, and interpret quantitative results from MO theory.

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