Keggin杂多阴离子电子结构和物化性质与中心原子的关系

Relationships of Electronic Structures and Physico - chemical Properties of Keggin Anions on Central Atoms

使用密度泛函理论中的离散变分方法(DFr-DVM),以(XMo12O40)n-(X=B,Al,Si,Ge,P,As,S)为例计算了七个Keg-n杂多阴离子的电子结构,讨论了中心原子对Keggin阴离子的电子结构、稳定性、氧化还原性和酸性的关系.根据计算结果,给出稳定性、氧化还原性强弱顺序,计算给出结果与实验一致.

The electronic structures of Keggin - type heteropolyanions (XMo12O40)(n-) (X = B, Al, Si, Ge, P, As, S)have been calculated by the Density Functional Theory coupled with Discrete Variational Method (DFT-DVM). Based on the calculated results of the seven heteropoly anions, we discussed the influence of the central atoms on the electronic structure, stability, oxidizability and acidity. These results give the sequences of (1) stability, (2) acidity and (3) oxidizability of seven heteropoly anions respectively, as follows: (1) (SMo12O40)(2-) > (AsMo12O40)(3-) > (PMo12O40)(3-) > (GeMo12O40)(4-) > (BMo12O40)(5-) > (SiMo12O40)(4-) > AlMo12- O-40)(5-); (2)H2SMo12O40>H3AsMo12O40>H3PMo12O40>H4GeMo12O40>H4SiO12O40>H-5 AlMo12O40> H5BMo12 O-40; (3) (SMo12O40)(2-) > (ASMo(12)O(40))(3-) > (PMo12O40)(3-) > (GeMo12O40)(4-) > (SiMo12O40)(4-) > (AlMo12O40)(5-) > (BMo12O40)(5-). These sequences are strongly supported by many experimental results.