Synthesis, characterization and properties of series coordination polymers constructed from a biphenyl dicarboxylate and nitrogen-containing mixed ligands

Abstract

A series of coordination polymers have been prepared by the combination of flexible ligand 1,1′-biphenyl-2,2′-dicarboxylic acid (H 2dpa) and different types of nitrogen-containing ligands, with various metal ions such as Co(II), Zn(II) and Cd(II). The single-crystal structure analyses reveal that the above complexes possess different structure features with the introduction of different nitrogen-containing ligands. When auxiliary linear ligand 4,4′-bipyridine (4,4′-bpy) is introduced, two-dimensional layered complex, [Co 2(dpa) 2(4,4′-bpy) 2(H 2O)] n ( 1) is formed. Whereas if chelating ligand, 1,10-phenanthroline (1,10′-phen) and 2,2′-bipyridine (2,2′-bpy) are introduced, one-dimensional complex [Zn(dpa)(1,10′-phen)] n ( 2) and discrete complexes [Co 2(dpa) 2(2,2′-bpy) 2(H 2O) 2] ( 3), [Co 3(dpa) 3(1,10′-phen) 6(H 2O) 2] ( 4), [Cd(dpa)(1,10′-phen) 2][(H 2dpa) 2(H 2O) 2] ( 5) are synthesized. To our interest, 1 and 2 crystallize in homochiral spacegroup. Furthermore, the magnetic property of complex 1 and the fluorescent properties of complexes 2 and 5 are studied.