Effects of Metal Ions and N-Donor Ligands with Different Coordination Characters on the Construction of d10 Metal-organic Complexes with Selective Photocatalytic Activities

Four new d¹⁰ metal-organic coordination polymers, [Zn(L)(phen)(H₂O)] (1), [Cd(L)(phen)] (2), [Zn(L)(bppdc)]·3H₂O (3), and [Cd(L)(bppdc)]·3H₂O (4) [L = 2-carboxymethylsulfanyl nicotinic acid, phen = 1,10-phenanthroline, bppdc = N, N′-bis(pyridin-3-yl)pyridine-2,6-dicarboxamide], have been obtained from hydrothermal reactions of zinc(II)/cadmium(II) nitrates with the semi-rigid N-/S-containing dicarboxylate L, and the two structurally disparate neutral N-donor ligands phen and bppdc. Single-crystal X-ray diffraction analysis has revealed that compound 1 is a one-dimensional (1-D) helical coordination polymer linked by Zn^II atoms and L spacers. Compound 2 features a double-chain structure connected via binuclear Cd^II units and pairs of L linkers. Adjacent chains of 1 and 2 are packed into 3-D supramolecular networks by hydrogen bonds and π-π stacking interactions. Compounds 3 and 4 exhibit similar 2-D (4,4)-connected wave-like networks based on linear [M-L]_n and zigzag [M-bppdc]_n metal-organic chains (M = Zn^II for 3 and Cd^II for 4). The effects of metal ions and N-donor ligands with different coordination characters are discussed. Moreover, the photoluminescence properties and photocatalytic activities of compounds 1–4 were investigated.