SiO_2·(CO)_n(n=1～2)结构和属性的理论研究

Density Functional Theory Study on Structures and Properties of Si_2·(CO)_n(n=1~2)

用密度泛函理论详细地研究了SiO2·(CO)n(n=1～2)的结构和属性.研究表明,SiO2·CO是一个T形的具有C2V对称性的分子,SiO2·(CO)2具有C2对称性的分子;频率计算结果与实验值一致,CO在与SiO2成键过程中,C-O伸缩振动频率有所增加,说明静电势在复合过程中起了重要作用;基组重叠误差(BSSE)修正在计算相互作用能时不可忽视,相互作用能和解离能的计算以及NBO分析表明,SiO2·(CO)2中的SiO2与CO之间的作用相对SiO2·CO来说较弱;SiO2和CO2与CO的成键特点不同,主要是缘于SiO2与CO2的能隙不同.

The structures and properties of Si_2·(CO)\-n(n=1~2) have been studied in detail on Density Functional Theory(DFT).The results indicate that Si_2·CO is a T shape and C\-(2V) symmetry molecule, and Si_2·(CO)\-2 is a C\-(2) symmetry molecule. Calculated frequencies agree with experiment value well, and the C-O stretch frequency increased during the binding process of CO and Si_2 indicates that static potential play important role in the binding process. Interaction energies show that basis set superposition error (BSSE) can't been neglected. The interaction energies and the characterized binding energies have been calculated; Si_2 and C_2 binding with CO are different for the different character of front orbitals.