catena-Poly[[aquanickel(II)]-μ-pyridine-2,6-dicarboxylato-[aquanickel(II)]-μ-2,5-di-4-pyridyl-1,3,4-thiadiazole]

Abstract

The two independent NiII ions in the one-dimensional title complex, [Ni2(C7H3NO4)2(C12H8N4S)(H2O)2]n or [Ni2(pydc)2(bpt)(H2O)2]n (H2pydc = pyridine-2,6-dicarboxylic acid and bpt = 2,5-di-4-pyridyl-1,3,4-thiadiazole), have different coordination environments. One NiII ion is in a slightly-distorted octahedral coordination environment formed by three O atoms from two adjacent pydc ligands, two N atoms from bpt and pydc ligands, and one water molecule, while the other NiII ion is in distorted square-pyramidal geometry, coordinated by two O atoms from two carboxylate groups and two N atoms from the pyridine rings of the pydc and bpt ligands in the basal plane, while a coordinated water molecule occupies the apical site. In the crystal structure, the H atoms of both water molecules are involved in intermolecular hydrogen bonds with the O atoms of uncoordinated carboxylate groups, which link chains into a three-dimensional network.