α和β构型八钼酸根的理论研究

Theoretical studies on isomers of α-and β-[Mo_8O_(26)]^(4-)

本文用考虑了零级微扰近似相对论效应的RI-TPSS/def2-SVP方法计算了八钼酸根的α和β两种异构体的几何结构。然后在TPSSh/def2-TZVPP水平(考虑了ZORA相对论效应)下计算了相关电子性质并进行了自然键轨道分析和总态密度分析。ZORA-RI-TPSS/def2-SVP水平能非常好的重复晶体结构。分子的负电荷分布到体系中的各个氧原子上,并且氧原子配位数越大,其带负电荷就越大。Mo-O键主要由Mo的4d轨道与O的sp3杂化轨道重叠形成。α和β构型的八钼酸根的氧化性相差不大,与八钼酸根催化硫醚氧化反应实验结果是一致的。

Molecular structures of α-and β-Mo8O264-were investigated at the RI-TPSS/def2-SVP level in the gaseous phases with full geometry optimization including the relativistic zeroth-order regular approximation（ZORA）.Then,the electronic properties,natural bond orbital（NBO）analysis,and total density of state（TDOS）analysis were performed at the TPSSh/def2-TZVPP（ZORA）level.The optimized geometry structures of α and β-Mo8O264-are in good agreement with that of X-ray.The negative charge is distributed over all types of oxygen atoms,and the individual values are observed to increase with the coordination number.All Mo-O interactions have been found to be predominantly 4d（Mo）-sp3（O）in character.The oxidation behavior of α-and β-Mo8O264-is very nearly the same,which is in agreement with the catalytic activity of thioether oxidation.