**************** The 16th., Lab Seminar *****************

Date: Mon, November 7, 2005  PM 1:30-

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

Speaker: Haruko Hitomi

Title: An Electrostatic Model of Methyllithium Tetramer, a Non-nonclassial System
Andrew Streitwieser
Journal of Organometallic Chemistry 156 (1978) 1-3.

Abstract:　
 A collection of 4 positive and 4 negative point charges arranged as two
interpenetrating tetrahedra subject only to Coulombic forces has a minimum
electrostatic energy at a ratio of the two tetrahedra sides of 0.783, a value
consistent with the observed Li-Li to C-C distance ratio of 0.73 in the 
structure of methyllithium tetramer.

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Title: Application of point charge and HSE force field models to group 1 
organometallic terameric and hexameric aggregates
Richard J. Busbby and Helen L. Steel
Journal of Organometallic Chemistry 336 (1987) C25-C32.

Abstract:
 The ralative dimensions of group 1 (RM)4 tatramers can be accounted for
in terms of a simple point charge electrostatic model. Such a model cannot
be applied to the equivalent (RM)6 hexamer, but for these a hard sphere 
electrostatic model is reasonably successful. The findings support the view
that the structures of group 1 organomitallics are determined principally 
by electrostatic factors but not the argument that bonding in these 
compounds is wholly ionic.

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