Coordination Polymers with the Angular Dipyridyl Ligand 1,3,4-Thiadiazole-2,5-di-3-pyridyl: Influence of Analogue Dipyridyl Ligands and Bridging Anions on Structural Diversity

Abstract

The self-assembly of ZnII, CdII, and CuII salts with the angular ligand 1,3,4-thiadiazole-2,5-di-3-pyridyl (L1) and three secondary ligands, 1,3-di-4-pyridylpropane (L2), 4,4′-dipyridyl (L3), and 2,3-dimethylpyrazine (L4), produced six new one- and two-dimensional coordination polymers. The unusual two-dimensional bilayer coordination polymer [Zn(L1)(SO4)]n (1) obtained from L1, L3 (or L4), and ZnSO4·7H2O has SO42−-bridged chiral inorganic 1-D ladders that are wound by L1 from two unparallel directions to form a novel chiral channel structure. According to the same synthetic procedure of 1, only the displacement of L3 (or L4) with L2, however, afforded the one-dimensional coordination polymer {[Zn(L1)2(H2O)(SO4)](H2O)2}n (2). Interestingly, the elegant dipyridyl ligands L2, L3, and L4, unlike their analogue L1 coordinating to metal ions, affect the structural configuration of the resulting single crystals, even though they do not exist in these compounds. Another 2-D bilayer coordination polymer, [Cd(L1)(...