Synthesis and Crystal Structure of a Co(II) Coordination Polymer Derived from a Flexible Bipyridyl Derivative Ligand

摘要

The self-assembly of a flexible bipyridyl ligand 2,2'-bis(4-pyridylmethyle- neoxy)-1,1'-biphenylene (4,4'-bpp) with cobalt(II) center gave rise to a one-dimensional chain complex [Co(μ-4,4'-bpp)2(SCN)2(H2O]n 1 which has been characterized by single-crystal X-ray diffraction. The polymer crystallizes in monoclinic, space group C2/c with unit cell parameters: a = 13.1888(13), b = 24.230(2), c = 15.4218(17) (A), β = 93.291(6)°, V = 4920.1(8) (A)3, Z = 4, C50H42CoN6O5S2, Mr = 929.95, Dc = 1.255 g/cm3, F(000) = 1932 and μ(MoKα) = 0.484 mm-1. The final R and wR are 0.0691 and 0.1670 for 3746 observed reflections with I > 2σ(I). 1 possesses an infinite 1-D polymeric chain structure consisting of the repeated basic square units Co2(μ-4,4'-bpp)2, where the Co(II) center acts as the joint of the square ring. The Co(II) center is coordinated in a slightly distorted octahedral geometry with four nitrogen atoms from four different 4,4'-bpp ligands in the equatorial plane and two trans thiocyanate ligands occupying the axial positions, preventing the formation of an extended framework.