含氧酸离子XO_n^(m-)的电子结构与性质的关系

THE RELATIONSHIP BETWEEM THE ELECTRIC CONFIGURATIONS OF OXY-IONS XO_n^(m-) AND THEIR PROERTIES

本文对一些含氧酸离子XO_n^(m-)(X=Cl,Br,I,S,Se,Te,P,Si)进行了CNDO计算。通过对Muiliken重迭集居数和重迭积分进行分割,计算得到了X—O键的σ和π杂化轨道。计算结果表明X—O键中存在较强的p-dπ配键,含氧酸的酸性与中心原子的价电子数、价电子层主量子数、氧原子数及p-dπ配键的强度密切相关。在文中报导了一个计算含氧酸第一电离常数pK_1的经验公式,理论计算值与实验值基本一致。

In this paper, some oxyions XO_n^(n-)(X=Cl, Br, J, S, Se, Te, P, Si) have been calculated by the CNDO metthod. By a way of partitioning of M-lliken overlap populations and overlap integrals, the σ and π hybrid orbitals of the X-O bonds are obtained. The results show that the X-O π bonds are of the p-dπ type and that the oxoacid properties depend on a valence electronic number, the main quantum numbers of valence electrons, a coordination number and the p-dπ bond strength. In addition, an equation for computing of the ionisation constants is proposed. By employing this equation, the ionisation constants of some oxoacids are computed and are mostly in good agreement with the experiments.