Syntheses,Crystal Structures and Thermal Stabilities of Two New Mixed Ligated Coordination Polymers with Rigid Dicarboxylate and Flexile N-donor Ligands

Two new coordination polymers,[Co(BIPA)(bpp)](1) and [Zn(BIPA)(bpp)(H2O)](2)(H2BIPA = 5-bromoisophthalic acid,bpp = 1,3-di(4-pyridyl)propane) have been synthesized via hydrothermal reactions.The two compounds were characterized by elemental analysis,IR spectra,TG analysis and single-crystal X-ray determination.Compound 1 crystallizes in triclinic,space group P1 with a = 9.0316(13),b = 10.1179(14),c = 11.8884(17) ,α = 68.022(2),β = 84.749(2),γ = 77.791(2)°,V = 984.5(2) 3,Z = 2,C21H17BrN2O4Co,Mr = 500.21,Dc = 1.687 g.cm-3,μ = 2.932 mm-1,S = 0.981,F(000) = 502,R = 0.0440 and wR = 0.1357 for 3773 observed reflections with I > 2σ(I).Compound 2 crystallizes in the monoclinic system,space group P21/c with a = 7.8466(10),b = 27.483(4),c = 9.6583(13) ,β = 96.663(3)°,V = 2068.8(5) 3,Z = 4,C21H19BrN2O5Zn,Mr = 524.66,Dc = 1.685 g.cm-3,μ = 3.155 mm-1,S = 0.969,F(000) = 1056,R = 0.0441 and wR = 0.0517 for 4058 observed reflections with I > 2σ(I).The two compounds are constructed from the BIPA2-and bpp ligands but they exhibit different kinds of one-dimensional chain structures.In 1,the chains are composed of the Co(Ⅱ) ions and BIPA2-ligands,and the chains are further extended into a 2D framework structure by π...π interactions of the benzene rings from the BIPA2-ligands between the adjacent chains.In 2,the chains are made up of Zn(Ⅱ) ions and BIPA2-ligands through another fashion,and the chains are further linked via hydrogen bonding interactions to yield a two-dimensional supramolecular layer structure.Furthermore,the bpp ligand features two kinds of different coordination modes in the two compounds.