Synthesis, Structure And Properties Of Bis - Triazole Alkane MOFs

Metal-organic frameworks (MOFs) are crystalline materials with abundant aperture structure, which have attracted increased attention for their novel topological structures and potential applications in the areas of magnetism, catalysis, adsorption and luminescence, and so on. In this thesis, eleven transition metal complexes (Cd(Ⅱ), Zn(Ⅱ), Mn(Ⅱ), Cu(Ⅰ)) have been obtained with the ligands of bis(1,2,4-triazol-1-yl)alkane, pyrazine-2,3-dicarboxylic acid (H2pzdc) or cyano group by the method of solution evaporation or hydrothermal synthesis. The structures and properties of the metal complexes were determined by IR, X-ray single-crystal diffraction, TG and fluorescence. The conclusions are as follows:1. Five new metal complexes with the ligands of 1,2-bis(1,2,4-triazol-1-yl)-ethane(bte) or 1,4-bis(1,2,4-triazol-1-yl)butane(btb) and pyrazine-2,3-dicarboxylic acid have been synthesized by solution evaporation method, and the molecular structure formulas of complex 1,3,4,5 have been determined through X-ray single-crystal diffraction, formulated as{[Cd(bte)0.5(pzdc)(H2O)]·H2O}n (1)，{[Cd (btb)0.5(pzdc)(H2O)2]·H2O}n (3),{[Zn(btb)0.5(pzdc)(H2O)2]·H2O}n (4),{[Mn(btb)0.5 (pzdc)(H2O)2]·H2O}n(5).X-ray crystallography studies indicate that complex 1 displays a three-dimensional framework structure with a uniform channel, complex 3,4,5 are isomorphic complexes, and they display an interesting two dimensional wave-like structure which forms a distinct extended three dimensional supramolecular structure with the help of hydrogen bonds. The IR spectrum result shows that complex 2 is a Zn(Ⅱ) complex with pzdc2- anion and bte ligand.2. Six new Cu(Ⅰ) metal complexes with bis(1,2,4-triazol-1-yl)alkane and cyano group have been synthesized under hydrothermal conditions, formulated as [Cu3.5(btm)(CN)3.5]n(6), [Cu3(bte)(CN)3]n (7), [Cu4(btpr)(CN)4]n (8), [Cu2(btb)(CN)2]n (9), [Cu6(btpe)2(CN)6(H2O)3]n(10), [Cu(bth)0.5(CN)]n(11).X-ray crystallography studies indicate that complex 6-11 have three-dimensional framework structures, and the crystal structures of these complexes contain Cu-CN chain. Solid-state fluorescence analyses demonstrate that complex 6-11 exhibit strong fluorescence which may be generally assigned as metal-to-ligand charge transfer (MLCT).