Hydrothermal Synthesis and Crystal Structure of a 1D Cu（II） Coordination Polymer： [Cu（bbpy）（H_2bptc）]_n Constructed by a Tetracarboxylic Acid

The title compound [Cu(bbpy)(H2bptc)]n (bbpy = 4,4'-dimethyl-2,2'-bipyridine and H4bptc = 1,1'-biphenyl-2,2?,3,3'-tetracarboxylic acid) has been synthesized by hydrothermal reaction, and its structure was determined by X-ray diffraction and characterized by elemental analysis, IR spectrum and thermogravimetric analysis. The crystal is of triclinic, space group P1 with a = 11.2831(12), b = 11.6718(13), c = 11.7771(13), α = 105.392(2), β = 108.382(2), γ = 112.397(2)o, CuC28H20N2O8, Mr = 576.00, V = 1222.4(2)3, Dc = 1.565 g/cm3, F(000) = 590, μ = 0.951 mm-1, S = 1.022 and Z = 2. The final refinement gave R = 0.0405 and wR = 0.1142 for 4270 observed reflections with I > 2σ(I). The title complex has a 1D [Cu(bbpy)(H2bptc)]n chain structure, in which the extensive hydrogen-bond interactions make the chain more stable. The neighboring parallel chains are further packed into a 2D layer structure via π···π stacking interaction between the pyridine rings of bbpy ligands. Moreover, the adjacent layers are interconnected by the C-H···π interactions to form a 3D metal-organic framework.