Synthesis, Structures And Magnetic Properties Of Coordination Polymers Based On Flexible Multi-Carboxylate Ligands

Metal-organic coordination polymer and supramolecular chemistry is the new research field that gathers basic research and application. It will be one of the most active research areas at 21st century in chemistry and materials due to their potential applications in separation, asymmetric catalysis, magnetism, etc. This thesis mainly discuss the structures and properties of coordination polymers that constructed by flexible multi-carboxylate ligands and metal ions under solvothermal conditions. This thesis is divided into five chapters.In the first chapter, we introduced the basic conception, synthetic method and development of the coordination polymers and the research progress of coordination polymers based on carboxylate ligands as well as the significance and the progress made in this topic.In the second chapter, four coordination polymers, [Cu5(tci)2(OH)2(H2O)8][Cu2(tci)2]·11H2O (1), [Zn(tci)][(CH3)2NH2]·2.5H2O (2), [Cu(Hbci)(H2O)]·1.5H2O (3) and Zn(Hbci)(H2O)3 (4) have been successfully constructed by tris(2-cyanboxyehtyl)isocyanurate and bis(2-cyanboxyehtyl)isocyanurate.1 is a novel ionic compound that contains anionic CdI2-type layers, pentanuclear copper cluster cations and cyclic (H2O)18 clusters,2 is a CdI2-type layer,3 is a chain that contains paddle-wheel dimers and 4 is a 2D layer which contains Zn-O-Zn chains in the structure.In the third chapter, six coordination polymers, [Zn3(tci)2(bpy)1.5(H2O)2]·6H2O (5), [ZnNa(tci)(bpy)0.5(H2O)]·2H2O (6), [Zn2(tci)(trz)]·H2O (7), [Cu(Htci)(bpy)]·H2O (8), [Cu(H2tci)2(bpy)(H2O)]·2H2O(9), [Cu3(tci)2(bpp)2(H2O)]·3H2O (10) have been constructed by flexible tripodal carboxylate ligand, Cu(II)/Zn(II) ions and auxiliary bridging ligand under solvothermal conditions. The topological analyses of these coordination polymers were described in detail.5 is a three-fold interpenetrating 3D coordination polymer,6 is a two-fold interpenetrating 3D coordination polymer,8 is a two-fold interpenetrating 3D framework with CdSO4-type topology, and 10 is a complicated 3D structure which can be simplified into (3,4,6)-connected network.In the fourth chapter, two 3D Gd(III) coordination polymers, [Gd(tci)(H2O)]·DMF·2H2O (11) and [Gd(bci)(H2O)]·2H2O (12) have been solvothermally synthesized by the reaction of two different flexible carboxylate ligands and gadolinium nitrate. Two complexes are, actually,3D framework, but from magnetic viewpoint they can be considered as 1D chain entities. Athough they have the similar Gd-(μ-O)2-Gd chains, their magnetic properties are different because the Gd…Gd distances are not the same in the chains.11 is antiferromagnetic while 12 is ferromagnetic. The main factor that determines the magnetic properties of them is the Gd(Ⅲ)…Gd(Ⅲ) distances rather than the gap between the Gd-O bond length. This conclusion is in contrast to professor T. Hughbanks'deduction published in Journal of the American Chemical Society.In the fifth chapter, we have summarized the structures and properties of the twelve coordination polymers and highlighted the advantage of the flexible multi-carboxylate ligands in the construction of coordination polymers. We also summarized the factors that affect the structures of coordination polymers.