Syntheses, structures, and photocatalysis of five inorganic–organic hybrid compounds constructed from Keggin polyoxometalate clusters and multidentate N-donor ligands

Abstract

Five inorganic–organic hybrid compounds have been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction analyses, infrared spectra, elemental analyses, powder X-ray diffraction, and thermogravimetric analyses. In 1, each 2,2ʹ-tmbpt ligand links two Cu(II) ions to generate a highly undulated chain. The chains are further bridged by [SiW₁₂O₄₀]^4‒ anions to form a layer. Compound 2 exhibits a 3-D (3,4,5)-connected framework with large channels, in which [SiW₁₂O₄₀]^4‒ anions are tetradentate linkages. In 3, each 2,4ʹ-tmbpt links three Cu(II) ions to form 2-D layers, which are further linked by [SiW₁₂O₄₀]^4‒ to yield a 3-D (3,4)-connected framework. In 4, each 4,4ʹ-tmbpt connects three Cu(II) ions to generate 1-D double chains. In 5, [PW₁₂O₄₀]^3‒ link Cu(II) ions to generate 1-D chains. Compounds 1‒5 exhibit photocatalytic activities for degradation of methylene blue and rhodamine B.