Synthesis,Crystal Structure and Characterization of a New Coordination Polymer from the Self-assembly of CoCl_2 Salt and Flexible Ligand 1,3-Bis(4-pyridyl)propane

A new 1D coordination polymer [Co（bpp）3Cl2（H2O）2]n 1 （bpp = 1,3-bis（4-pyridyl）-propane） was synthesized and characterized by elemental analysis,IR spectrum and single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system,space group Ibca with a = 16.569（9）,b = 17.240（10）,c = 27.087（16） ,V = 7738（8） 3,Z = 8,Dc = 1.306 g/cm3,Mr = 760.65,λ（MoKa） = 0.71073 ,μ = 0.623 mm1,F（000） = 3192,the final R = 0.0678 and wR = 0.2011. The Co（II） atom is coordinated in a slightly distorted octahedral CoN4Cl2 geometry by two Cl atoms in the axial positions,four N atoms from the two bridging bpp ligands and two pendant bpp ligands. The CoN4Cl2 octahedra are connected by the bridging bpp ligands to form a 1D neutral coordination polymer chain. The chains are linked by face-to-face π-π interactions between adjacent pendant bpp ligands to give rise to a 3D supramolecular architecture. The photoluminescent investigation indicates that the emission of 1 is attributed to ligand-centered emission. The variable-temperature magnetic susceptibility measurement shows weak antiferromagnetic behavior in the coπmplex.