Semi-rigid imidazolium carboxylate controlled structural topologies in zwitterionic coordination networks

The zwitterionic coordination networks [L2Mn(H2O)(2)](infinity) (1), [L2Co(H2O)(2)](infinity) (2), [L2Ni(H2O)(4)](infinity) (3), [L2Cu](infinity) (4), [L2Zn(H2O)(2)](infinity) (5) and [L3Cd2(Br)(2)](infinity) (6) were synthesized from the reaction between the semi-rigid imidazolium carboxylate spacer LH2+Br- and the corresponding metal nitrates in DMF/H2O at 130 degrees C. The solid state structures of 1-6 were confirmed by the single-crystal X-ray diffraction technique. The molecules 1, 2 and 5 are isostructural one-dimensional coordination polymers. 3 was isolated as a monomer and the monomers are associated into a three dimensional fashion through O-H center dot center dot center dot O hydrogen bonds, while 4 was isolated as a 1D coordination polymer. Compound 6 was constructed as a two-dimensional coordination framework with a rare [Cd-2(mu(2)-Br)(2)] core. The purity of 1-6 in the bulk was confirmed by the powder X-ray diffraction technique. Furthermore the electronic properties of 1-6 were studied using UV-Vis spectroscopy and the thermal stabilities of 1-6 were confirmed by TGA. (C) 2015 Elsevier Ltd. All rights reserved.