The highest connected pure inorganic 3D framework assembled by {P4Mo6} cluster and alkali metal potassium

Abstract

A 3D high connected pure inorganic framework based on {P₄Mo₆} cluster, [{K(H₂O)}₁₂{CoMo₁₂^VO₂₄(OH)₆(HPO₄)₄(PO₄)₄}] (1) has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, UV analysis and single crystal X-ray diffraction analyses. In compound 1, each basic unit {Co(P₄Mo₆)₂} dimeric cluster uses its surface oxygen atoms (36) to attract 30 different-occupied potassium atoms at its periphery, which act as diverse bridge unit forming an centrosymmetric 18-connected open-framework with a (3³4³)₂(3⁶4¹²5⁶6⁴)(3⁶4⁸⁴5³⁶6²¹³7²⁷8⁶⁹)(4)₉ topology. Compound 1 represents the highest connection of the {P₄Mo₆}-based POMs up to now. Compound 1 shows bifunctional electrocatalytic activities toward not only reduction of nitrite and hydrogen peroxide, but also oxidation of biological molecules ascorbic acid (AA) ascribed to Mo^V-centers. In addition, compound 1 shows excellent photocatalytic activities for the degradation of methylene blue (MB).