Keggin型多阴离子[XW_(12)O_(40)]^(n-)(X=Si,Ge,P,As)电子性质的密度泛函理论研究

Density Functional Theory Study of the Electronic Properties of Keggin-type Heteropolyanions [XW_(12)O_(40)]^(n-)(X=Si,Ge,P,As)

采用密度泛函理论方法研究了Keggin型多阴离子[XW12O40]n-(X=Si,Ge,P,As)的电子性质,在几何优化基础上,分析杂原子对体系的几何结构,电子性质,氧化还原性质的影响。结果表明:杂原子对多阴离子的键长有影响,变化规律与杂原子半径递变一致;杂原子的电子性质影响多阴离子的氧化性,多阴离子的氧化能力随杂原子的电负性增大而提高;杂原子的核电荷数越大,该多阴离子的氧化性越强;多阴离子的酸强度与杂原子的电负性次序一致。

The electronic properties of polyanion [XW_（12）O_（40）]^（n-）（X=Si,Ge,P,As） were investigated by using density functional theory method.We analyzed the influence of the hetero-atoms on the geometry,electronic and redox properties.The results showed that the hetero-atoms were influential to the bond length of heteropolyanions,and the requlairety of change depended on the radius of hetero-atoms.Also,the electronic properties of hetero-atoms could affect the oxidizability of heteropolyanions.The oxidizability of heteropolyanions improved with the increase of the electronegativity of hetero-atoms and the larger the atomic nuclear charge the stronger the oxidizability of heteropolyanions.