Self-assembly and structures of new transition metal complexes with phenyl substituted pyrazole carboxylic acid and N-donor co-ligands

Five new transition metal complexes, [Ni(HL1)(2)(2,2'-bipy)]center dot 3H(2)O (1), [Ni(HL1)(2)(4,4'-bipy)] (2), [Co(HL1)(2)(4,4'-bipy)]center dot 5H(2)O (3), [Ni-2(HL2)(4)center dot(4,4'-bipy)center dot(H2O)(2)]center dot 4H(2)O (4), [Co(HL2)(2)center dot(4,4'-bipy)] (5) (H2L1 = 5-phenyl-1H-pyrazole-3-carboxylic acid; H2L2 = 3-phenyl-1H-pyrazole-4-carboxylic acid; 2,2'-bipy = 2,2'-bipyridine; 4,4'-bipy = 4,4'-bipyridine) have been synthesized and characterized. Complex 1 exhibits a monomeric structure, 2 and 3 display 1D chain structures, 4 and 5 possess 3D metal-organic frameworks with 1D channels, and all extend to 3D supramolecular networks via rich hydrogen bonds. Complex 4 shows a new (4,6)-connected network with (4(4).5(8).6(3))(5(4).6.8) topology, while 5 exhibits a NaCl-like network with (4(12).6(3)) topology. The thermal stabilities of complexes 1-5 and powder XRD of 4 and 5 were investigated. Furthermore, the antibacterial activities of the title complexes against the tested bacteria were studied and compared to the activities of the corresponding free ligands. (C) 2011 Elsevier B. V. All rights reserved.