磷—钒—钼杂多酸的降解过程及其降解产物的合成

Studies on Degradation of Vanado-Molybdo-Phosphoric Acids and Preparation of a Species of Their Degradation Products

研究了H_mPV_nMo_(12-n)(n=0～2)的降解过程,结果表明:随钒取代数n的增大,其降解产物愈趋稳定。对于钒取代数小的杂多酸。在降解过程中会自动转化成更稳定的钒取代数较大的降解产物。合成了H_5PV_2Mo_(10)O_(40)的降解产物(NH_4)_7H_2PV_2Mo_9O_(39)·15H_2O。利用紫外、红外、热重—差热、x射线粉末衍射等对所合成的产物进行了初步研究。

The degradation processes of H_mPV_nMo_(12-n)O_(40)(n = 0～2) are investigated. It is shown that stability of the degradation product increases while increasing in number of vanadium atom as a substituent for molybdenum contained in the heteropoly anions. In the solution, when its pH value raises, these anions tend to convert from lower vanadium substituent into higher one and also increase their stability. These heteropoly anions with lower content of vanadium substituent may also convert automatically into higher content. (NH_4)_7H_2PV_2Mo_9O_(39)·15H_2O as a degradation product of H_5PV_2Mo_(10)O_(40) is prepared and studied by using some instrumental methods such as UV and IR spectra, X-ray diffraction and tga-dta thermal analysis. A preliminary discussion of its structure is given.