Versatile coordinating capabilities of thiodibenzoic acid copper complexes bearing N-donor ligands

Cu(II) coordination polymers [Cu(tda)(phen)]1.5H(2)O (1a), [Cu(tda)(py)] (2a) and [Cu(tda)(bipy)(H2O)]0.5H(2)O (3a) (tda = thiodibenzoic acid, phen = phenanthroline, py = pyridine, bipy = bipyridine) have been synthesized by slow diffusion. Under solvothermal conditions, [Cu(tda)(phen)]2H(2)O (1b), [Cu(tda)(H2O)] (2b) and [Cu(tda)(bipy)] (3b) were isolated. The structures of the complexes 1a-3a have been determined by single X-ray diffraction. The experimental X-ray powder diffraction patterns of 1b-3b were compared with the calculated patterns of 1a-3a. The polymers were found to exhibit structural and dimensional diversity due to the effect of the co-ligands. In complexes 1a and 1b, tda is found to coordinate with the metal atom in a monodentate mode, while in 2a and 2b, the carboxylate oxygens are coordinated with the two metal centers in a mu-bridged bidentate fashion. The structural analysis of 3a shows that the copper atom is in a square pyramidal environment, whereby the metal atom is coordinated with the carboxylate oxygens of two different tda ligands in a monodentate fashion and two nitrogens of the bipyridine ligand and one coordinated water. The IR spectrum of 3b implies a bidentate mode of coordination.