Syntheses, Structures And Properties Of Coordiation Compounds Based On Ether-bridged Ligands Containing N Atoms, Double Schiff-base Ligands And Pyridine-N-oxide Ligands

The chemistry of organic-inorganic coordination polymers has recently become an activearea of increasing interest in chemical industry. Self-assembly of organic ligands and inorganicmetal ions is one of the most efficient approaches for the construction of organic-inorganiccomposite materials. In this thesis, a series of ether-bridged ligands capped by pyrimidyl orpyridyl groups, pyridine-N-oxide ligands and double schiff-base ligands were synthesized. Thecoordination chemistry of these ligands and metal ions was investigated and sixty compoundswere obtained. Their single crystal structures were fully characterized by X-ray single-crystaldiffraction. The physical and chemical properties of some compounds were also investigated.I. The coordination chemistry based on an open-chain polyether-bridged ligand (L1), which iscapped by pyrimidyl group, and transition metal ions was investigated and twelve novelcoordination compounds were obtained. An irreversible naked-eye detectable structuraltransformation from a3D Cu(I)-framework (Cu2(L1)(NO3)2(DMF)0.4) to a1D Cu(II)-chain(Cu(μ-OCH3)(L1)(NO3)) was observed. The dioxygen acts as an oxidant, while CH3OHmedium is the template for the formation of the cluster Cu2(μ-OCH3)2. Both of them are theindispensable factors to induce this transformation. The formed O2-·radical anion, an essentialactive species for the structural transformation, was trapped by DMPO and SOD, which is anunprecedented study of the mechanism of structural transformation.II. Nine novel coordination compounds were synthesized based on an open-chainpolyether-bridged ligand (L2), which is capped by pyridyl group, and transition metal ions. Inthe presence of several different carboxylate templates, the coordination chemistry based onL2and Cu(II), Zn(II), Cd(II), Co(II) salts was investigated and eleven novel coordinationcompounds were obtained. The study indicates that the structures of coordination compoundswere influenced by several factors, such as metal center, anion, auxiliary ligand etc, and theflexible ligand L2can adopt various conformations to meet the needs of different coordinationenvironments.III. Nineteen novel coordination compounds were obtained based on the pyridine-N-oxideligands with carboxyl groups and Pb(II), Ln(III). The different coordination sites of ligandsinfluence the structures of coordination compounds. With different reaction temperature, four Pb(II)-MOFs were synthesized, which show different color and the same structure. Thetunable emission (UV-vis) of Pb(II)-MOF was successfully realized based on the guest-drivenapproach.IV. A series of asymmetric ether-bridged ligands and double schiff-base ligands capped bypyrimidyl groups were synthesized. Nine novel coordination compounds were obtained basedon them, and the single crystal structures of them were investigated.