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

► We have synthesized two Ni(II) complexes with 2-carboxymethylsulfanyl nicotinic acid. ► The complexes were structurally characterized by single-crystal X-ray diffraction. ► Complex 1 is linked by hydrogen bonds into a 3D 5-connected topology network. ► Complex 2 exhibits an uninodal 4-connected twofold interpenetrating dia topology network.