Syntheses, Structures And Characteristics Of Coordination Polymers With2-methylimidazole

Imidazole and their derivatives are often choiced for building metal-organic coordination polymers, The organic bridging ligand2-methylimidazole groups have many characteristics such as strong coordination ability and their coordination polymers have good magnetic, luminescent, adsorption properties and the broad prospects of the function of new materials and super-molecular self-assembly.In the work, we have synthsized eleven coordination polymers using flexible ligand1,4-bis(2-methylimidazol-1-ylmethyl) benzene and transition metal cations Zn(Ⅱ), Cd(Ⅱ), Co(Ⅱ), Cu(Ⅱ), Mn(II):{[Zn(bmix)2(1,3-bdc)]}n (1),{[Zn2(bmix)2.5(SO3-bdc)Cl]·2.5H2O}n(2),{[Zn(bmix)(OH-bdc)]}n(3),{[Zn(bmix)0.5(glu)]}n (4),{[Cd2(bmix)2(fum)Cl2]·0.5H2O}n (5),{[Cd(bmix)Cl(OH-pha)]}n (6),{[Cd2(bmix)(chda)2]}n (7),{[Co(bmix)(glu)]·4H2O}n (8),{[Co(bmix)0.5(glu)]}n (9),{[Cu2(bmix)0.5(2-OH-bdc)]·H2O}n (10),{[Mn(bmix)(1,4-bdc)]-2H2O}n (11). These compounds have been synthesized and characterized by IR, elementary analysis, X-Ray Powder Diffraction analyses and thermogravi-metric analysis.Through the synthesis and study of these coordination polymers, we found that ligand bmix as a bridge to connect two centers presents the gauche or anti conformation and formed one-dimensional chain structure6and11; two-dimensional network structure3,7and8; three-dimensional microporous network2; Coordination polymers1,4,5,9and10display the three-dimensional network structure. The structure of2is an unusual three-dimensional system formed by parallel polythreaded of four-fold polycatenated three-dimensional microporous network. The structure of the complexe9is also very unique, metal ions connected with carboxylic acid ligand H2glu formed a two-dimensional grid, two-dimensional grid connected to each other by ligand bmix formed a novel three-dimensional system. The unique structure of these complexes not only provide an attractive sample of channel system, but also expand the study.