Synthesis, Crystal Structure and Physical Properties of a Novel Cadmium(II) Supramolecular 3D Framework

A new inorganic-organic hybrid cadmium(II) complex [Cd-2(H(1/2)C(4)BIm)(2)(CH3COO)](n), has been prepared by a hydrothermal reaction, and characterized by fluorescence, IR, TGA, and single-crystal X-ray diffraction analysis. In its crystal structure, there are two kinds of coordinating forms for those Cd(II) ions. One is that the Cd(II) ion is coordinated by one carboxylate oxygen atom from one acetate oxygen ligand and three benzimidazole nitrogen atoms from three 2,2'-(1,4-butanediyl)bis (1H-benzimidazole) (H(2)C(4)BIm) ligands, and the other is that the Cd(II) ion is coordinated by four benzimidazole nitrogen atoms from four H(2)C(4)BIm ligands to furnish two distorted tetrahedral coordination geometries. It exhibits a beautiful structure for a 2D layer and a 3D network, with its four-connecting nodes provided by the H(2)C(4)BIm ligands. Furthermore, this complex shows intense luminescent property at room temperature. In [Cd-2(H(2)C(2)BIm)(2)(C9H6O4)(2)](n), the H(2)C(2)BIm ligand lost the role as a bridging ligand because of the shorter alkyl chain compared with that of H(2)C(4)BIm ligand.