The introduction of metal sites into molecular metal oxides, so-called polyoxometalates, is a key approach to tune their structure and reactivity. To-date, the complex solution mechanisms which govern metal-functionalizatio of polyoxometalates is still poorly understood. Here, we reveal the existence of a coupled set of light-dependent and light-independent reaction equilibria control the mono- and di-metal-functionalization of a prototype molecular vanadium oxide cluster. Comprehensive mechanistic analyses show that coordination of a single Mg2+ ion to the native species (NMe2H2)2[V12O32Cl]3- results in formation of the mono-functionalized system (NMe2H2)[(MgCl)V12O32Cl]3-. This species is photoactive, and irradiation with visible light triggers a second, light-dependent reaction equilibrium which drives the formation of the di-metal-functionalized species [(MgCl)2V12O32Cl]3-. The use cations which compete with Mg2+ can effectively inhibit the formation of the metal functionalized clusters. The study therefore demonstrates how external and internal stimuli can be used to control supramolecular polyoxometalate assembly.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.