Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5418683 | Journal of Molecular Structure: THEOCHEM | 2007 | 8 Pages |
Abstract
Some η5-cyclopentadienyl cobalt dithiolene complexes CpCoS2C2R2 have been optimized at B3LYP/6-311++G(d) level. The optimized geometries agree well with experiment. The analyses of nature bond orbital and nucleus-independent chemical shift (NICS) at B3LYP/6-311++G(d) and GIAO-B3LYP/6-311++G(d) levels reveal the aromatic character of the η5-cyclopentadienyl cobalt dithiolene complexes. However, their aromaticity is weaker than that of the isolated CoS2C2+1. There are two reasons for the change of heterocyclic aromaticity of the metal dithiolene in the η5-cyclopentadienyl cobalt dithiolene complexes with respect to that of the isolated CoS2C2+1. The better equalization of bond lengths in the isolated cation CoS2C2+1 is the first reason. The other reason is that the contribution to the NICS from the metallic cobalt atom is much larger in the isolated cation CoS2C2+1. The planar character of cyclopentadienyl is destroyed slightly in the complexes. At the same time, the size of cyclopentadienyl (Cp) becomes bigger than the isolated Cpâ1 and this is caused by the cobalt atom in the pentagon. The Ï-electron delocalization causes stronger aromaticity of the Cp in the complexes than that of the isolated Cpâ1.
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Yan-Hong Cui, Wei Quan Tian, Ji-Kang Feng, Zi-Zhong Liu, Wei-Qi Li,