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) (L1)0.5·(H2O)]n (1) and {[Zn(3,4′-bpdc) (L1)]·(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 44-sql layers by parallel polycatenation. The photoluminescent properties of 1 and 2 have also been investigated.