Structures And Properties Of Functional Coordination Polymers Based On1,6-bis(2-methyl-imidazole-1-yl)Hexane

Metal-Organic Frameworks (MOFs) constructed by flexible imidazole ligand have attracted the immense attention of the coordination chemists. Not only for their flexibility changing of the topologies, but also owing to their potential applications in the nonlinear optical, photoluminescence properties, electrical magnetic, biological activity, catalysis, and gas adsorption. Choosing appropriate imidazole ligands and using crystal engineering principle to design of the Metal-Organic Frameworks (MOFs), which exists in special structure and unique characters. In this paper, we designed and synthesized a flexible ligand1,6-bis(2-methyl-imidazol-1-yl)hexane, allocated organic acids as building blocks and inorganic salts to form MOFs. Finally, we obtained twelve coordination polymers based on flexible bis(imidazole) ligand under the guidance of the principle of coordination polymer crystal engineering.[Zn(bimh)(chda)]n(1),[Cd(bimh)(bda)H2O]n(2),[Cd(bimh)(oba)]n(3),[Zn(bimh)(oba)]n(4),[Co(bimh)(oba)]n(5),[Cd(bimh)(dtsa)]n(6),[Cu(bimh)(oxa)]n(7),[Cd(bimh)(ipa)]n(8),[Zn(bimh)(tma)·(bimh)]n(9),[Zn(bimh)(ipa)H2O]n(10),{[Zn(bimh)(ipa)]-(CH3CH2OH)0.5}n(11),[Zn(bimh)(ada)]n(12),(bimh=1,6-bis(2-methyl-imidazole-1-yl)hexane, H2chda=1,4-cyclohexanedicarboxylic acid, H2bda=2,2’-biphenyldicarboxylic acid, H2oba=4,4’-oxybis(benzoic acid), H2dtsa=2,2’-dithiosalicylic acid, H2oxa=oxalic acid, H2ipa=isophthalic acid, H3tma=trimesic acid, H2ada=azobenzene-4,4’-dicarboxylic acid). The target coordination polymers have been characterized by X-ray single crystal diffraction, XRPD analysis, elemental analyses, IR spectra, fluorescence spectroscopy and thermal analysis.Paper structure is divided into three parts:In Chapter1, it introduces briefly the development of coordination chemistry, the basic concepts of crystal engineering, the synthesis methods and structures of coordination polymer, and research progress of coordination polymers with flexible bis(imidazole) ligands.In Chapter2, seven novel coordination polymers based on1,6-bis(2-methyl-imidazol-1-yl)hexane, auxiliary flexible organic acids ligands and inorganic salts have been synthesized successfully. Polymer1affords the two-dimensional (2D) net, and these2D structures are further assembled into3D network through aromatic π-π stacking. Compound2affords the1D ladder net and hydrogen bonds into the3D network. Compounds 3,4and5has a similar structure, all possess2D layer structures and contain1D helical chains.6shows homochiral3D metal-organic framework with a3-fold interpenetrating uniform network (86) and exists in two types of helical chains. Complex7exhibits1D meso-helical chains.In Chapter3, five novel coordination polymers based on1,6-bis(2-methyl-imidazol-l-yl)-hexane, auxiliary rigid carboxylic acid ligands and inorganic salts have been synthesized successfully. Complex8exhibits2D wave-like layer structures. Polymer9shows a3D2-fold interpenetrating net. The different of pH value when we obtained10,11leading to10forms1D line chain structures but11exhibits2D layer structures. Compound12contains simple one-dimensional (1D) helical chains assembled into a four-connected two-dimensional (2D)2-fold interpenetration network. Moreover, the helical chains co-use the shafts with the vicinal helical chains in the2-fold interpenetration network.