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Syntheses, Crystal Structures, and Magnetic Properties of Metal−Organic Hybrid Materials of Cu(II):  Effect of a Long Chain Dicarboxylate Backbone, and Counteranion in Their Structural Diversity

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journal contribution
posted on 16.04.2007, 00:00 by A. K. Ghosh, D. Ghoshal, E. Zangrando, J. Ribas, N. Ray Chaudhuri
Eight new metal−organic hybrid materials of Cu(II) have been synthesized by using flexible glutarate/adipate as a bridging ligand, 2,2‘-bipyridine/1,10-phenanthroline as a chelating ligand, and BF4-/ClO4-/Cl- as a counteranion. These materials are characterized by single-crystal X-ray diffraction analyses and variable temperature magnetic measurements. Out of them, complexes 1, 3, 5, and 8 crystallize in the triclinic system with space group P1̄. Complexes 2, 4, 6, and 7 crystallize in the monoclinic system with space group P21/n (2, 4), P21/c (6), and C2 (7). The structural analysis reveals that bridging glutarate gives rise to dinuclear and tetranuclear species, whereas the adipate dianion leads to octanuclear, one-dimensional and two-dimensional polymeric complexes, although they have been prepared under similar conditions. Supramolecular architectures of higher dimensionality have been achieved through H-bonding and π−π interaction. In all the complexes, the bridging and/or counteranions as well as chelating ligand have a vital role in directing the solid-state structure. A variable temperature (2−300 K) magnetic susceptibility study discloses the antiferromagnetic coupling for all of the complexes.