羰基硼化合物B2n(CO)n (n＝1～6)的理论研究

运用密度泛函理论(DFT)的B3LYP/6-31G*方法, 对羰基硼化合物B_2n(CO)_n (n＝1～6)各种可能的结构进行了优化,对它们的几何构型、电子态、振动频率、核独立化学位移(NICS)和B₂CO的分子轨道进行了理论研究, 得到了B_2n(CO)_n (n＝1～6)结构的稳定性信息. 在它们的基态结构中, 羰基的配位方式是端配位(μ₁-CO), B_2n(CO)_n (n＝1～5)的基态构型是线形或平面结构, B₁₂(CO)₆的基态构型则较为复杂. B_2n(CO)_n (n＝1～3)的基态是三重态, B_2n(CO)_n (n＝4～6)的基态是单重态. 振动频率和轨道的研究为实验提供了重要的理论依据.

Theoretical Investigation of Boron Carbonyl Compounds B2n(CO)n (n=1～6)

The structures of B_2n(CO)_n (n＝1～6) compounds were studied by B3LYP with basis set of B3LYP/6-31G*. By discussing the geometries, electron structures, vibrational frequencies, nucleus independent chemical shifts (NICS) of the most stable structures and B₂CO molecule orbital, we got the stable information of B_2n(CO)_n (n＝1～6) compounds. Among all of the ground states structures, the ground states of B_2n(CO)_n (n＝1～5) are linear or planar, B₁₂(CO)₆ is appreciably intricate, and the carbonyls of ground state B_2n(CO)_n (n＝1～6) are μ₁-CO. The ground state structures of B_2n(CO)_n (n＝1～3) are triplet, and the ground state structures of B_2n(CO)_n (n＝4～6) are singlet. The analyses of the vibrational spectra and molecule orbital provide some important direction on the experiment.