Two new Nickel(II) complexes constructed by 2-carboxymethylsulfanyl nicotinic acid with different N-containing auxiliary ligands

Two new Ni(II) complexes, [Ni2(2-CMSN)2(bpp)2(H2O)4]·1.5H2O (1), [Ni(2-CMSN)(4,4′-bipy)1.5(H2O)]·0.75H2O (2) (2-H2CMSN = 2-carboxymethylsulfanyl nicotinic acid, bpp = 1,3-bi(4-pyridyl)propane, 4,4′-bipy = 4,4′-bipyridine), have been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra and TG analyses. Single-crystal X-ray diffraction analysis reveals that they present two different structures. Complex 1 is 2D structure and further linked by hydrogen bonds into the final 3D 5-connected topology network. Complex 2 can be considered as a uninodal 4-connected twofold interpenetrating dia topology network. Photoluminescence studies reveal that complexes exhibit fluorescence quenching in the solid state at room temperature. The cyclic voltammograms of the complexes reveal that the processes of the redox are both irreversible.