Two octamolybdate-based coordination polymers with high photocatalytic activities under visible light irradiation

Abstract

Two coordination polymers based on octamolybdate and 2-aminopyrazine, namely, [CuI2(HL)2(L)(β-[Mo8O26])]·3H2O (1) and [(H2L)2(β-[Mo8O26])]·4H2O (2) (L=2-aminopyrazine), have been synthesized hydrothermally. The structures of the compounds were determined by single-crystal X-ray diffraction analyses and further characterized by infrared spectra, elemental analyses, powder X-ray diffraction analyses and thermogravimetric analyses. Compound 1 displays a double chain structure, which is extended by the intermolecular NH⋯O hydrogen-bonding interactions to generate a 3D supramolecular architecture. Compound 2 exhibits a discrete structure, which is connected by the intermolecular OH⋯O hydrogen-bonding interactions to yield a 3D supramolecular architecture. Compounds 1 and 2 display small band gaps of 1.89 and 1.66eV, respectively. Moreover, compounds 1 and 2 exhibit high photocatalytic activities for degradation of methylene blue under visible light irradiation.