Effects of Direction of Bridging of Thiocyanato on the Dimension of Coordination Polymers: Synthesis, Characterization and Single-crystal X-ray Structure Determination of [Cd(4,4'-dm-2,2'-bpy)(NCS)_2]_n and [Cd(4,4'-dmo-2,2'-bpy)(NCS)_2]_n Coordination Pol

Two new cadmium（II）-thiocyanato coordination polymers with 4,4＇-dimethyl-2,2＇-bipyridine（4,4＇-dm-2,2＇-bpy） and 4,4＇-dimethoxy-2,2＇-bipyridine（4,4＇-dmo-2,2＇-bpy） as chelating ligands were synthesized and characterized by elemental analysis, IR and 1H NMR spectroscopy and X-ray crystallography. Thermal properties were also studied as well. These complexes have formed as [Cd（4,4＇-dm-2,2＇-bpy）（NCS）2]n（1） and [Cd（4,4＇-dmo-2,2＇-bpy）（NCS）2]n（2）. The coordination numbers of CdII in 1 and 2 are six（Cd N4S2）. Direction of bridging of thiocyanato anions in 1 and 2 created one- and two-dimensional coordination polymers, respectively. The supramolecular features in these complexes were guided and controlled by weak directional intermolecular interactions.