Effect of Different Imidazole Ancillary Ligands on Supramolecular Architectures of a Series of Zn(II) and Cd(II) Complexes with a Bent Dicarboxylate Ligand

Five new complexes, namely, {[Zn(L)(L1)]center dot(H2O)(DMF)(2)}(n) (1), {Cd(L)(L1)(0.5)}(n) (2), {[Zn-2(L)(2)(L2)(2)]center dot DMF}(n) (3), {[Zn(L)(L3)]center dot(H2O)5}(n) (4), and {[Cd-2(L)(2)(L3)(1.5)(H2O)](2)center dot H2O}(n) (5), have been synthesized by the solvothermal reaction of 4,4'-(hexafluoroisopropylidene)bis(benzoic acid) (H2L) with different transition metal ions in the presence of ancillary ligands 1,4-bis(imidazol-1-ylmethyl)benzene (L1), 4,4'-bis(imidazol-1-ylmethyl)-biphenyl (L2), and 4,4'-bis(benzimidazol-1-yl-methyl)biphenyl (L3). Complex 1 displays a two-dimensional (2D) framework containing two kinds of ring units. In complex 2, one-dimensional (ID) Cd chains are assembled by L2- and L1 ligands into a non-interpenetrated three-dimensional structure. Complex 3 possesses a 2D framework which is generated by joining both P and M helices by L2- ligands. The structure of 4 is a three-dimensional (3D) framework with {4(2).6.8(3)} net containing meso-helices, while 5 is a 2D structure with {4(14).6} net. The photoluminescent properties of 1-5 have been studied in the solid state at room temperature.