Multidimensional networks constructed with isomeric benzenedicarboxylates and 2,2'-biimidazole based on mono-, bi-, and trinuclear units

Three new complexes of [Co(H(2)biim)(2)(1,2-bdc)] (1), [Cd(H(2)biim)(1,3-bdC)](2) (2), and [Cd3(H(2)biim)(2)(1,4-bdc)(3)]center dot 2H(2)O (3) (bdc = benzenedicarboxylate, H(2)biim = 2,2'-biimidazole) have been synthesized and characterized by single-crystal X-ray diffraction. Complex 1 exhibits a 2-D herringbone architecture with mononuclear building blocks assembled via a robust hydrogen-bonded synthon R-2(2)(g). The homo- and heterochiral assemblies were observed in 1 between the H(2)biim ligand and carboxylate group via single and double hydrogen-bonded synthons R-2(2)(g). Complex 2 is a ribbonlike polymer based on a binuclear unit, and the ribbons are alternately decorated by H(2)biim ligands on both sides and further packed through intercalation of the lateral H2biim ligands and hydrogen bonds between the H(2)biim and carboxylate oxygen atoms into 2-D networks. These layers extend into a 3-D architecture via pi-pi stacking interactions. Complex 3 is a 3-D coordination polymer with a alpha-Po net topology based on linear trinuclear {Cd3O14N4} clusters. The results indicate that isomeric benzenedicarboxylates give structural diversity in the presence of auxiliary ligand H(2)biim, providing a potential tool for crystal engineering.