Polyoxometalates (POMs) function as platforms for synthesizing structurally well-defined inorganic molecules with diverse structures, metals, compositions, and arrangements. Although post-editing of the oxygen sites of POMs has great potential for development of unprecedented structures, electronic states, properties, and applications, facile methods for site-selective substitution of the oxygen sites with other atoms remain limited. Herein, we report a direct site-selective oxygen–sulfur substitution method that enables transforming POMs [XW12O40]4− (X = Si, Ge) to Keggin-type polyoxothiometalates (POTMs) [XW12O28S12]4− using sulfurizing reagents in an organic solvent. The resulting POTMs retain the original Keggin-type structure, with all 12 surface WO groups selectively converted to WS without sulfurization of other oxygen sites. These POTMs show high stability against water and O2 in organic solvents and a drastic change in the electronic states and redox properties. The findings of this study represent a facile method for converting POMs to POTMs, leading to the development of their unique properties and applications in diverse fields, including (photo)catalysis, sensing, optics, electronics, energy conversion, and batteries.
Synthesis of polyoxothiometalates through site-selective post-editing sulfurization of polyoxometalates
