1,4-Bis(imidazole)butane ligand and strontium(ii) directed 1-D chains based on basket-type molybdophosphates and transition metal (TM) linkers

Abstract

Five unclassical heteropoly blues, (H₂bib)₃[{TM^II(H₂O)₂}{Sr⊂P₆Mo₂^VMo₁₆^VIO₇₃}]·nH₂O (TM = Fe (1), Co (2), Ni (3), Cu (4), Zn (5)); bib = 1,4-bis(imidazole)butane), have been hydrothermally synthesized and fully characterized. Compounds 1–5 are based on the basket-shaped [Sr⊂P₆Mo₂^VMo₁₆^VIO₇₃]⁸⁻ (abbreviated as {P₆Mo₁₈O₇₃}) units, which consist of a vacant Dawson-type “basket body” {P₂Mo₁₄} unit and a “handle”-like {P₄Mo₄} fragment encasing a Sr²⁺ cation in the central cage. All the compounds exhibit isostructural 1-D zigzag chains linked by a {TM(H₂O)₂} unit, which are observed for the first time as 1-D basket-like assemblies connected by a TM linker. The optical band gaps of 1–5 show that they are semiconductor materials and potential photocatalysts. Compound 2 as a representative catalyst exhibits a universal highly efficient degradation ability for typical dyes MB, MO, and RhB under UV light and bifunctional electrocatalytic behavior for oxidation of AA and reduction of NO₂⁻.