多酸阴离子的光致变色现象

Photochromism of Polyoxometalate

综述了多酸阴离子的光致变色的研究进展,着重介绍了同多钼酸胺、八钼酸盐、同多和杂多钨酸盐的结构特征以及光致变色的特点,阐述了多酸阴离子的光致变色机理。金属氧化物的光致变色通常是由杂质或晶体缺陷造成的。多酸阴离子的光致变色是由于在光照下,电子从氧的低能态的2p轨道跃迁到金属高能态的d轨道,即配体中的氧→金属(O→M)电荷转移(LMCT)的结果。

The progress in photochromism of polyoxometalate is reviewed. The structures and photochromism characteristics of alkylammonium polyoxometalate, octamolybdates and iso-and polytungstic acids and the mechanism of photochromism of polyoxometalate are introduced. Metal oxides are photochromic when they contain impurities or crystal defects, but photochromism of polyoxometalate upon irradiation results from the transition of electrons from the low energy oxygen 2p orbitals to the hight energy metal d orbitals, namely, the electron transfers from oxygen in the coordination compound→metal(O→M).