Abstract
A series of the multicomponent heteropolysilicates with the same structure has been synthesised by a controllable method. Studies on the correlation between the redox properties and composition of the polyoxometalates indicate that the character of the addenda ion has the highest influence on the oxidising ability of the heteropolyanions for a given structure, and by comparison, the effects of the number of the addenda ions and the charge of the whole heteropolyanions were not completely prominent in mixed-addenda tungstomolybdosilicate heteropolyanions. For transition metal-substituted heteropolyanions, however, the effect of the number of the addenda ions is an important factor and stronger than that of the character of the addenda ion (transition metal ion) in some cases. On the other hand, incorporation of a transition metal ion can lead to a decrease of the reversibility of redox for heteropolyanions.