Synthesis,Structure And Properties Of Coordination Polymer Based On 5-iodo-isophthalic Acid

In this thesis,the assembly between the multifunctional 5-iodoisophthalic acid(H2iip)and transition metal ions in the presence of the polypyridine long-chain ligands,N,N’-bis(2-pyridylmethyl)formamide(2bbpum),N,N’-bis(3-picolylmethyl)formamide(3bbpum),N,N’-bis(4-picolylmethyl)formamide(4bbpum),N,N’-bis(3-picolylmethyl)urea(3bpmu),3-pyridinecarboxaldehydeisonicotinylhydrazone(pepo),results in eight new coordination polymers(CPs).These complexes were characterized by single crystal X-ray diffraction analysis,FT-IR spectroscopy,solid-state diffuse relectance UV-vis-NIR spectroscopy,thermogravimetric analysis(TG),powder X-ray diffraction(PXRD)anaysis and elemental analysis,etc.Considering the structural characteristics of the as-synthesized complexes,the optical and electrochemical properties of them were investigated respectively.The main content is shown in the following three aspects:1.The assembly between H2iip and Mn2+in the presence of 2/3/4bbpum at room temperature using the typical volatilization method leads to the formation of three new CPs:{[Mn(iip)(2bbpum)0.5(H2O)3]-2H2O}n(1),{[Mn(iip)(3bbpum)0.5(H2O)]·0.5(3bbpum)}n(2)and {[Mn(iip)(4bbpum)(H2O)]·H2O}n(3),respectively.1～3 belong to the triclinic system,P-1 space group.The central Mn2+ion is six-coordinated.In particular,the 2bbpum ligand in 1 binds with the central Mn(Ⅱ)ion only through the amide oxygen atom,while the 3/4bbpum ligand in 2 and 3 coordinates with the Mn(Ⅱ)ion through the pyridine nitrogen atom.There are lattice 3bbpum molecules in 2 and lattice water in 1 and 3.Under the joint action of the hydrogen bonds 1D chain of 1 and 2D framework of 2 and 3 extend into 3D supramolecular network.2 and 3 show strong fluorescence emissions in water,and can selectively and sensitively sense Fe3+.Interstingly,3 demostrates sensitive sensing to Cr(Ⅵ)in water,but 2 doesn’t.2.Adopting the synthetic stradge of changing temperature and pH,the assembly between H2ⅱp and Co2+ in the presence of 4bbpum leads to the formation of three new CPs:{[Co(ⅱp)(4bbpum)1.5(H2O)]·1.5H2O}n(4),{[Co(ⅱp)(4bbpum)(H2O)]·H2O}n(5)and {[Co(ⅱp)(4bbpum)]·1.5H2O}n(6),respectively.Among them,4 belongs to the monoclinic crystal system,the P21/n space group.The center Co2+in 4 is penta-coordinated and exhibits square-pyramidal geometry.If the Co2+ion were treated as node,both the ⅱp2-and 4bbpum were treated as linkers,4 can be simplified as a 3D two-fold interperitrated network with the topological symbol of 44.66.5 and 6 belong to the triclinic crystal system,P-1 space group.The central Co2+is a hexacoordinated,which is connected by the ligands to form a two-dimensional framework.With the help of the hydrogen bonding,2D framwork of 5 and 6 further extend into a 3D supramolecular structure.4 and 5 show excellent fluorescence responses to Fe3+ and Cr(Ⅵ),and have the potential as fluorescent probes.3.The assembly between H2iip and Cd2+ion in the presence of 3bpmu/pepo results in two new 2D CPs,namely,{[Cd3(ⅱp)3(3bpmu)4.5]·4H2O}n(7)and{[Cd(ⅱp)(pepo)]·H2O}n(8),respectively.7 and 8 belong to the monoclinic crystal system,C2/c space group.The central Cd2+ion in 7 and 8 is six-coordinated.7 and 8 has similar 1D chain structure.The difference is that 7 shows a RNA-like single-stranded structure,while 8 is a DNA-like double-stranded structure.The electrochemical studies reveal that the composite membranes formed by 7/8 and Nafion showed excellent proton conduction behavior.