Recent advances in alkoxylation chemistry of polyoxometalates: From synthetic strategies, structural overviews to functional applications

Polyoxometalates (POMs), an exceptional family of coordination clusters consisting of Mo, W, V, etc. early transition metal ions in their highest oxidation states, have received significant attention over recent years due to their structural versatility and unique and diverse chemical and physical properties. The functionalization of POMs with organic ligands provides a novel strategy to precisely incorporate POMs with advanced functional organic moieties on their surfaces and enhance their compatibility in organic media. Among the various organically functionalized synthetic strategies for POM-based organic–inorganic hybrid materials, alkoxylation of POMs stands for one of the hottest topics during the past decades, since the diverse and tunable alkoxyl ligands are able to anchor on the surface of many POMs clusters, forming novel and flexible organically functionalized POM clusters, which can be further exploited as building blocks to design various functionalized POM-based hybrids with charming catalytic properties, and biomedicine, energy, or functional materials applications. In this review, recent advances in alkoxylation chemistry of POMs from synthetic strategies, structural overviews to their functional applications have been discussed.