Synthesis, Structures And Properties Of Metal-Organic Supramolecules Based On Multi-carboxylic Ligands

The design and synthesis of new functional metal-organic supramolecular complexes in coordination chemistry, supramolecular chemistry, crystal engineering is one of the active research fields in recent years, due to their special properties in new topology, photoelectricity, magnetism, molecular recognition and catalysis etc. In this thesis, we try to synthesize novel coordination complexes by use of flexible and rigid dicarboxylate ligands to assemble with transitional metal ions or rare-earth metal ions. The assembly of dicarboxylate with metal ions yielded 17 novel metal-organic complexes. All complexes have been determined by single-crystal X-ray diffraction、elemental analyses、XRPD analysis、thermal analysis and fluorescence spectroscopy. There are following five chapters:In chapter i:A brief introduction of the coordination chemistry, crystal engineering, supramolecular chemistry, coordination polymers and other basic concepts and principles. Selective focus on the development of coordination polymers described in a new direction and new ideas.The chapter ii:First designed and synthesized the flexible dicarboxylate ligand (H2L1～H2L4, H2L9, H2L10) with the right angle, by their self-assembly with transition metal ions, we have got nine metal organic complexes: Cd2(L1)2(DMF)4(H2O)2-H2O(2), Tm2(L1)2(DMF)4(NO3)2(2), Cu4(L3)4(H2O)4-3DMF(3), Cu4(L4)4(DMF)2(EtOH)2·8DMF·6H2O(4), Mn4(L4)4(DMF)4(H2O)4·6DMF·H2O(5), Mn3(L4)3(DMF)4·2DMF·3H2O(6), [Zn(L9)(phen)]·4H2O(7), [Zn4(L10)3(μ3-OH)2(H2O)2]·2H2O·2EtOH(8)和Mn3(1L2)2(2L2)(DMF)2(H2O)2·5DMF(9). X-ray diffraction structure analysis showed they were zero-dimensional crystal structure of metal organic macrocycle, zero-dimensional metal-organic coordination cage and one- / two-dimensional coordination polymer. In the zero-dimensional ring or cage-like structure, flexible ligand adopted cis-configuration, but in the one-dimensional or two-dimensional structure, the flexible ligand adopted the trans configuration or both cis- and trans configurations.In chapter iii:By changing the positions of the functional groups, there continually synthesized H2L6～H2L8 ligand, the positions of the functional SBUstituents in the central benzene ring change gradually from 1,2-,1,3- to 1,4-position. By applying these flexible ligands to assemble with copper ions, four metal-organic supramolecules (10-13) based on paddlewheel SBU have been isolated. Complexes 10 and 11 are discrete molecular chairs. Complex 12 is a 1D molecular-chair-based coordination polymer. The molecular chairs, similar to that found in 10 and 11, are infinitely connected by the bridging 4,4’ -bipy ligands to result in the formation of the 1D chain structure. Complex 13 is a two-dimensional wavelike layer structure containing 68-membered ring. Both L6 and L7 in 10 and 11 adopt cis, cis conformation, while L8 adopts cis, trans conformation, which results in the formation of the 2D layer structure of complex 13.In chapter iv, The assembly of iodine-based rigid dicarboxylate ligands H2atiip with zinc or cadmium ion, there are isolated four one-dimensional coordination complexes (14-17):[Zn(atiip)(bpy)·3H2O] (14,15), [Cd(atiip)(Im)2] (16), [Cd(atiip)(DMF)] (17) (Im=imidazole). Complexes 14 and 15 are one-dimensional metal-organic nanotubes, which are supramolecular isomers, complex 16 is a non-chiral zigzag chain, complexes 17 are one-dimensional chiral helical chains(by adding chiral inducer).In chapter v, The conclusions and prospects.