Coordination Polymers Constructed from Semi-Rigid N,N '-Bis(3-pyridyl)terephthalamide and Dicarboxylic Acids: Effect of Ligand Isomerism, Flexibility, and Identity

Reactions of the semi-rigid N,N '-bis(3-pyridyl)terephthalamide (L) with divalent metal salts in the presence of dicarboxylic acids afforded [Cd(L)(0.5)(1,2-BDC)(H2O)](n) (1,2-H2BDC = benzene-1,2-dicarboxylic acid), 1, {[Cd(L)(1.5)(1,3-BDC)(H2O)].5H(2)O}(n) (1,3-H2BDC = benzene-1,3-dicarboxylic acid), 2a, {[Cd(1,3-BDC)(H2O)(3)].2H(2)O}(n), 2b, {[Cd(L)(0.5)(1,4-BDC)(H2O)(2)].H2O}(n) (1,4-H2BDC = benzene-1,4-dicarboxylic acid), 3, and [Cu(L)(0.5)(5-tert-IPA)](n) (5-tert-IPA = 5-tert-butylbenzene-1,3-dicarboxylic acid), 4, which have been structurally characterized by single crystal X-ray diffraction. Complexes 1 and 3 are two-dimensional (2D) layers with the bey and the hcb topologies, and 2a and 2b are one-dimensional (1D) ladder and zigzag chain, respectively, while 4 shows a 3-fold interpenetrated three-dimensional (3D) net with the cds topology. The structures of these coordination polymers containing the semi-rigid L ligands are subject to the donor atom positions and the identity of the dicarboxylate ligands, which are in marked contrast to those obtained from the flexible bis-pyridyl-bis-amide ligands that form self-catenated nets. The luminescence of 1 and 3 and thermal properties of complexes 1, 3, and 4 are also discussed.