Azole Aromatic Carboxylic Acid And Pyridine Evil Mixed Ligand Coordination Polymer Synthesis, Characterization And Nature Of The Study

The work of this thesis focuses on the preparation of metal organic frameworks based on mixed ligands system of dipyridyl ligands and multi-carboxylate acid ligands. We successfully obtained 13 novel coordination polymers in different reaction conditions. X-ray single-crystal diffraction, elemental analysis (EA), infrared spectroscopy (IR) and thermogravimetric analysis (TGA) were performed. The soild luminescent properties of some materials are also investigated. There are mainly three parts in this thesis:First, we prepared MOFs based on 2,5-bis (3-pyridyl)-1,3,4-oxadiazole (3-bpo) and multicarboxylic acid (H3btc,p-H2bdc,m-H2bdc). We chose Ni(II) and Zn(II) to coordinate with the mixed ligands and obtained six one-dimensional complexes: [Ni(3-bpo)(Hbtc)(H2O)2]n·(H2O)n (JL-1), [Ni(3-bpo)(m-bdc)(C2H5OH)2]n (JL-2), [Ni(3-bpo)(m-bdc) (H2O)]n-(H2O)n (JL-3), [Ni(3-bpo)2(p-bdc) (H2O)2]n·2(H2O)n (JL-4), [Zn(3-bpo)(Hbtc) (H2O)]n·(H2O)n (JL-5), [Zn(3-bpo)2(p-bdc)(CH3OH)2]n 2(CH3OH)n (JL-6), we also investigated how the metal center and solvent affect on the synthesis and structures of the compounds. Their structures have been determined by single crystal X-ray diffraction analyses. In addition, JL-1, JL-4, JL-5 and JL-6 generate 3D supramolecular networks through hydrogen bond andπ…πinteraction.Second, we obtained four higher dimension MOFs based on the 3-bpo,4-bpo and multicarboxyl acids (o-H3btc,p-H2bdc, m-H2bdc) by the hydrothermal reaction with metal salts Zn(II), Ni(II) and Cd(II):[Zn2(4-bpo) (o-bdc)2]n (JL-7), [Ni(3-bpo) (p-bdc)]n·(H2O)4n (JL-8), [Cd(4-bpo)(w-bdc)(H2O)]n (JL-9), [Cd2(m-bdc)2(3-bphH2) (H2O)2]n (JL-10). The single-crystal X-ray diffraction measurement reveals that JL-7 is a compact (46·64) 3D net while JL-8 and JL-9 shows a (4,4) 2D grid net. JL-10 shows a (4·64·8) (42·63·8) 2D net and pack to 3D supramolecular networks through hydrogen bond. The 3-bphH2 ligand of JL-10 was obviously in situ generated from the starting materials 3-bpo via a hydrolysis reaction along with the ring-open of the oxadiazole ring.Third, we designed and synthesized complexes based on the 2,5-bis(3-pyridyl)-1, 3,4-oxadiazole (3-bpo) and carboxylic acid ligand. We chose Co(II) and Ni(II) to coordinate with mixed ligands and obtained three zero-dimensional complexes:[Ni(3- bpo)(CH3COO-)2(H2O)2]·(H2O) (JL-11), Ni(3-bpo)(m-bdc)(CH3OH)2]·(CH3OH) (JL-12), [Co2(3-bpo)2(m-bdc)2(H2O)4]-2(3-bpo)-4(C3H7OH)(JL-13). The single-crystal X-ray diffraction measurement reveals that the metal center lies in the center of a little distorted octahedral environment. JL-11 is a discrete bimetal circle while JL-12 and JL-13 exhibit bimetal cages due to the introduction of m-H2bdc. The complexes were packed through weakπ…πreactionIn addition, The thermal stability and fluorescent properties of some materials have been investigated, they present high thermal stability and show great blue solid luminescent properties, which can be utilized as a kind of potential photo-luminescent materials.