Two New Zn(II) Coordination Polymers Constructed from Asymmetric Biphenyl-Dicarboxylate and Imidazole-Containing Ligands: Structures and Photoluminescent Properties

Two new coordination polymers, [Zn(2,4'-bpdc) (L-1)(0.5)center dot(H2O)] (n) (1) and {[Zn(3,4'-bpdc) (L-1)]center dot(H2O)} (n) (2), have been obtained from hydrothermal reactions of zinc (II) nitrate with the ligands 1,4-bis(imidazol-1-yl)benzene (L) and two asymmetric biphenyl-dicarboxylate [biphenyl-2,4'-dicarboxylate (2,4'-bpdc) and biphenyl-3,4'-dicarboxylate (3,4'-bpdc)]. Single-crystal X-ray diffraction analysis the two coordination polymer show different structures due to the different dicarboxylate ligands. Complex 1 features a 3D mab topological net. Complex 2 is unusual case that has 3D frameworks constructed from 2D 4(4)-sql layers by parallel polycatenation. The photoluminescent properties of 1 and 2 have also been investigated.