抄録
Voltammetric and Raman and NR spectroscopic studies on the formation of heteropolyoxometalate anions are discussed. Formation conditions of molybdophosphates were compared with those of molybdoarsenates in aqueous solution. The V(V)-substitution reactions of Keggin-type molybdoarsenates were investigated in aqueous and aqueous-organic solutions, which were compared with those of the corresponding molybdophosphates. Novel heteropolymolybdates containing X2O7 and XO3 oxoanions, such as P2O74-, PHO32- and so on, were isolated as n-Bu4N+ salts in aqueous-organic solution, and their formation conditions were elucidated. A few complexes of them gave four-electron reduction waves. It is noted that water-miscible organic solvents, such as acetonltrlle and acetone, played important roles on the formation and stabilization of heteropolyoxometalate anions.
