Three transition metal complexes constructed from a rigid 2,2′-bipyridine-3,3′,6,6′- tetracarboxylic acid ligand: Syntheses, structures and their fluorescence properties

Three complexes, {[Cd(bptcH(2))(H2O)]center dot H2O}(n) (1), {[Cu(bptc)(0.5)(H2O)]center dot H2O}(n) (2), {[Co-2(bptc)(H2O)(6)]center dot 3H(2)O}(n) (3) (bptcH(4) = 2,2 '-bipyridine-3,3 ',6,6 '-tetracarboxylic acid) have been synthesized by self-assembly of the rigid bptcH(4) ligand and corresponding transition metal salts. The structural analysis indicates that complex 1 displays a two-dimensional (2D) puckered sheet with (4(4).6(2)) topology built from 4-connecting Cd3N2(OOC)(3) cluster and bridging ligand bptcH(2)(2). Complex 2 features a one-dimensional (1D) double-stranded chain made up 4-connecting bptc(4) and Cu4N2(OOC)(4) cluster. Complex 3 also exhibits a 2D grid with (4(4).6(2)) topology, similar to that of complex 1. In addition, the fluorescence properties of complexes 1 and 3 have also been explored. (C) 2014 Elsevier B.V. All rights reserved.