Ligand-Isomerism Controlled Structural Diversity of Zn(II) and Cd(II) Coordination Polymers from Mixed Dipyridyladipoamide and Benzenedicarboxylate Ligands

By using isomeric N,N′-di(2-pyridyl)adipoamide (L1), N,N′-di(3-pyridyl)adipoamide (L2) and N,N′-di(4-pyridyl)adipoamide (L3) and isomeric 1,2-benzenedicarboxylic acid (1,2-H2BDC), 1,3-benzenedicarboxylic acid (1,3-H2BDC) and 1,4-benzenedicarboxylic acid (1,4-H2BDC), eight Zn(II) and Cd(II) coordination polymers [Zn(1,2-BDC)(L2)]∞, 1; [Zn2(1,3-BDC)2(L2)(H2O)2]∞, 2; [Zn2(1,4-BDC)2(L1)(H2O)2]∞, 3; {[Zn2(1,2-BDC)2(L3)(H2O)2]·2H2O}∞, 4; {[Cd(1,2-BDC)(L2)(H2O)]·H2O}∞, 5; [Cd2(1,3-BDC)2(L2)(H2O)4]∞, 6; {[Cd2(1,4-BDC)2(L2)2]·(H2O)3}∞, 7; [Cd2(1,4-BDC)2(L1)(H2O)2]∞, 8, have been synthesized under hydrothermal conditions. Complexes 1, 4, and 5 form 1D double-looped chain, 1D chain with loops and 2D layer with loops, respectively, and complex 6 exhibits a 1D ladder chain. Complex 2 shows rare 3-fold interpenetrated hcb layers, in which each layer interdigitates with other four parallel layers by directing the 1,3-BDC ligands into the windows of the adjacent nets, whereas complexes 3 and 8 forms planar and undulated ...