α-Keggin结构钼硅四电子杂多蓝的量子化学研究

采用半经验的INDO法,首次完成了α-Keggin 结构钼硅四电子杂多蓝K~ 3H~ 5Simo^v~4-Mo^Ⅵ~8O~4~0].12H~2O量子化学计算,获得102个成键轨道和68 个反键轨道,轨道能级,键序及电荷等数据,证明了杂多酸盐还原产物杂多蓝,还原后Keggin结构阴离子中各原子上电子云密度重新分配,产生一定程度的结构畸变, 但仍保持α-Keggin结构,最高占据轨道由组成分子的各原子轨道组成,其中的桥氧(O~b'O~c)成分较多,表明O~b'O~c为分子中的主要化学活性点HOMO和LUMO为负值, 表明仍可进一步接受电子生成四电子以上的杂多蓝,Muliken分析进一步证明了还原钼原子的位置.

The quantum study on four-electron heteropoly blue of α-keggin structure

Semiempirical INDO method has been used for calcns. on four-electron Keggin structure heteropoly blue molybdosilicate. The frontier mol. orbitals, orbital energies, bond orders, and atomic charges have been obtained. It is indicated that the structure of the heteropoly blue molybdosilicate with Keggin structure is distorted. The highest occupied orbitals in which there is more composition of bridge oxygen Ob and Oc are consisted of orbitals of all atoms in the mol. Mulliken anal. shows that the reduced Mo atom has more neg. charge.