Syntheses, structures and properties of three transition metal coordination polymers based on semi-rigid 3-pyridylnicotinamide and S/N-containing dicarboxylate mixed ligands

Abstract

Three new coordination complexes, [Co(L)(ADTZ)]·H2O(1), [Cd(L)(ADTZ)]·H2O(2) and [Zn(L)(ADTZ)]·H2O(3)[L=3-pyridylnicotinamide, H2ADTZ=2,5-(s-acetic acid)dimercapto-1,3,4-thiadiazole], were synthesized under hydrothermal conditions. These complexes were structurally characterized by single-crystal X-ray diffraction analysis and further characterized by infrared spectroscopy(IR), powder X-ray diffraction(PXRD) and thermogravimetric analysis(TGA). Complexes 1–3 exhibit the similar 2D double-layer networks based on 1D [M-L] n zigzag chains and 1D [M-ADTZ]2n double-chains with different distances between metal ions and with various conformations of ADTZ anions. In complexes 1 and 3, the 2D sheets are extended into a 3D supramolecular frameworks by hydrogen bonding interactions. The subtle effects of the central metal atoms on the structures of the title coordination polymers were discussed. The electrochemical properties of complex 1 and luminescent properties of complexes 2 and 3 were investigated. In addition, complexes 1–3 exhibit photocatalytic activity for dye methylene blue degradation under UV light and show good stability toward photocatalysis.