Dawson结构钼砷杂多酸(盐)的合成与性质研究

采用酸化-回流-乙醚萃取法合成了二十种Dawson结构钼砷杂多酸及其盐, 元素分析确定了它们的组成, 其通式为MwAs2Mo18Oe2.nH2O, 酸碱及电导滴定确定了碱度, 系统地研究了它们的红外光谱, 紫外光谱, 极谱, 循环伏安, 热重-差热分析等性质, 给出了杂多阴离子As2Mo18O62^6^-在水溶液中的氧化还原机理,讨论并指认了紫外吸收为e→*和e→b2的荷移跃迁谱带, 考察了抗衡离子M^n^+对主要红外振动光谱, 热分解温度及其分解产物的影响。

The syntheses and characterization of dawson structure molybdoarsenic acid and salts

Twenty molybdoarsenic acid and salts MxAs2Mo18O62.nH2O (M = NH4+, Li+, Na+, K+, Cs+, Ca2+, Mg2+, Sr2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Al3+, La3+, Ce3+, Pr3+, Nd3+, Sm3+, Gd3+) with Dawson structure, were synthesized and characterized by IR and UV spectroscopy, polarog., cyclic voltammetry and thermogravimetry. Hexa-basicity were established using conductive and acid-base titrns. The reduction mechanism of As2Mo18O626- in aqueous solution is suggested. The UV bands of the compounds were assignedf as e ?e* and e ?b2 transition according to the energy levels of MO's of MOL5 type compounds with C4v symmetry. The effects of the countercations Mn+ on the IR spectra, thermal decomposition temperature and decomposition products are discussed.