抄録
In this paper, a topic about recent theoretical calculations for di-chromium(I) complex and its related complexes is introduced. In 2005, a synthesis of a novel complex which has a short Cr(I)-Cr(I) bond was reported by Power's group. In the paper, they also indicated that the complex had a quintuple Cr(I)-Cr(I) bond with DFT calculations. Interestingly, other complexes consisted of Fe and Co ions did not show such a short metal-metal bond even if one used same ligands. In order to explain the structures of those complexes, they optimized the geometries by theoretical calculations. First, they optimized the Cr(I)-Cr(I) bond with simple ligands and the results indicated that the multiple bond is the origin of the short Cr-Cr bond. They, next, suggested an importance of an interaction between metal and π electrons of phenyl ligands. Their calculations indicate that the interaction seems to elongate metal-metal bonds especially for Fe and Co complexes although it hardly affects to the Cr(I)-Cr(I) bond length.
