Synthesis and structural characterization of supramolecular cadmium(II)-2,2′-biimidazole coordination polymers

Three polymeric compounds [Cd(SCN)(2)(H(2)biim)](n) (1), [Cd(N-3)(2)(H(2)biim)](n) (2) and [Cd-2(NO3)(dca)(3)(H(2)biim)(2,5)](n) (3) (H(2)biim=2,2'-H(2)biimidazole, dca=dicyanamide), have been synthesized and characterized. Compound 1 forms a 1D chain where [CdS2N4] octahedra are doubly bridged by two mu(1,3)-SCN- ligands. These chains are stacked together through hydrogen bonds and pi-pi interactions forming a 2D supermolecular network. In compound 2, the [CdN6] octahedra are doubly bridged by two mu(1,1)-N-3(-) bridges to form a chain. These chains are stacked together through hydrogen bonding interactions forming a 3D supermolecular structure. In compound 3, the Cd2 ions are alternately bridged by two mu(1,5)-dca(-) and one mu(3,3')-H(2)biim bridge along b-axis and form a chain. These chains are bridged by mu(1,5)-dca(-) to form a plane. Cd1 and Cd2 atoms are bridged by one dca(-) with Cd1 locate at either side of the plane. The luminescent properties of these compounds were studied. CCDC: 657894, 1; 657895, 2; 657896, 3.