Cr(CO)_6的结构浅析

Study about the structure of Cr(CO)_6

Cr(CO)6是典型的羰基配合物。其构型为正八面体,成键时Cr原子采取d2sp3杂化,CO分子与Cr原子之间以σ—配键结合。CO提供的是5σ分子轨道中的一对电子,Cr原子的dxy轨道(有孤对电子)与CO分子的2π反键轨道重叠形成π—配键。由于这种σ—π配键的形成所产生协同效应,是Cr(CO)6稳定存在的依据。

Cr(CO)6 is a typical coordinat carbonyl complex. Its geometrical configuration is octahedral, the Cr atom is d2sp3 hybridizaion,the chemical bond between CO molecule and Cr atom is σ-coordinate bond. A pair of electrons in 5σ molecular orbital is donated by CO,then the π-coordinate bond is formed by overlapping the dzx orbital of Cr atom (there is lone electron pair) and 2πantibonding orbital of CO molecule. When the σ-π coordinate is formed,the synergistic effect takes place, and this is the reason why the Cr(CO)6 molecule can exist steadily.