Zinc(II) and copper(II) complexes constructed from new bis(1H-1,2,3-triazole-4-carboxylate)-based ligands

Abstract

Using triazolyl based ligands bearing carboxylate groups and cationic species [Cu(NN)(acac)(H2O)]+ and [Zn(NN)2(acac)]+ seven new coordination complexes have been synthesized: [Cu2(bipy)2(7a-2H)(H2O)2](7a-2H)⋅2H2O⋅4DMF 8, [Cu(phen)(7a-2H)]⋅7H2O 9, [Zn(bipy)(7a-2H)]⋅6H2O⋅DMF 10, [Zn(phen)(7a-2H)]⋅4H2O⋅2DMF 11, [Cu(phen)(7b-2H)(H2O)]⋅3H2O 12, [Zn(bipy)2(7b-2H)2(H2O)2]⋅4H2O 13 and [Zn(phen)(7b-2H)(H2O)2]⋅2H2O 14, 7a = 1,1′-(sulfonylbis(4,1-phenylene))bis(1H-1,2,3-triazole-4-carboxylic acid), 7b = 1,1′-(1,4-phenylene)bis(1H-1,2,3-triazole-4-carboxylic acid), bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline, acac− = acetylacetonate anion. Compound 8 is a dinuclear complex, where 7a-2H dianions function as bridging and uncoordinated ligand. Compounds 9-11 are 1-D coordination polymers with the angular spacer 7a-2H connecting the metal nodes in zig-zag chain motives. The mono- (12, 14) and dinuclear (13) units are generated by employing 7b as ligand. The supramolecular solid-state architecture is sustained by the presence of π-π stacking interactions (involving the pyridyl and phenyl group of the bis(1H-1,2,3-triazole-4-carboxylate) anions and co-ligand molecules) and hydrogen bonds (established between the aqua ligands, lattice water molecules and carboxylate groups).