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Three cases of aminobenzoic acid hybrid polyoxotungstates, Na3(H3O)2[(HPW6O21) (O2CC6H4NH2)3]·7H2O (1), K2(H3O)4[(AsW6O21)(O2CC6H4NH2)3]·4H2O (2), and [(H2N(CH3)2]3Na2(H3O)[(SbW6O21) (O2CC6H4NH2)3]·7H2O (3), were successfully synthesized. This is the first report of the successful assembly of the hexanuclear {XW6} (X = HPIII, AsIII, or SbIII) clusters and organic carboxylic acid (para aminobenzoic acid) ligands. All three hybrids feature a common {XW6} unit composed of a six-membered {WO6} octahedral ring capped by one {XO3} trigonal pyramid. Furthermore, these hybrids possess an extensive three-dimensional network of hydrogen bonds, which not only provide high thermal stability but also contribute to excellent proton conductive performances. Simultaneously, based on the Hirshfeld partition analysis, combined with the interaction between POMs and water molecules, the proton transport mechanisms of three hybrids were highlighted.

Revealing the design and synthesis of precisely tailored crystalline catalysts for achieving efficient photocatalytic conversion of styrene into high-value-added products remains a challenging task. In this work, a highly stable crystalline polyoxovanadate functionalized by the dl-tartaric acid ligand H2[V4O4(H2O)6(tart)2]·H2O [1, tart = C4H2O6] was successfully synthesized by conventional aqueous solution methods. The photocatalytic performance was evaluated for the photosynthesis of styrene oxide by employing an oxygen source as the oxidant in the visible light (>420 nm) conditions at room temperature with compound 1as a heterogeneous catalyst. Furthermore, compound 1manifested accomplished stability and reusability, maintaining a high reaction activity even after three consecutive reaction cycles. This paper not only contributes to broadening the structural diversity of polyoxovanadate but also sheds new light on green catalytic conversion.