Coordination Complexes Supported By Sulfhydryl Triazoleand Sulfhydryl Thiadiazole-carboxylic: Syntheses, Structures And Properties

In recent years, with the mutual penetration and intercross of different subject realm, the coordination chemistry has developed toward the functional coordination polymers. This trend has found an even greater pace. Coordination polymers containing mercapto-group or N-heterocycle have gained great interest, because they possess variety of structures and excellent properties, and have potential applications in the fields of medicine, biology protein, optics, gas adsorption, magnetic materials, catalytic hydrogen production, nanometer materials, etc. In this paper, we synthetized two ligands which contain mercapto-group or N-heterocycle: one is 4-amino-3-(2-pyridyl)-1H-1,2,4-triazole-5-thione(2-aptt H), and the other is 2-(4-pyridyl)-1,3,4-thiadiazole-5-thio-acetate(4-Sptta). With the introduction of trigid aromatic carboxylic acids, the ligand 2-aptt H self-assembles with different metal ions to construct seven coordination complexes. And the ligand 4-Sptta self-assembles with different metal ions to give a series of coordination complexes. Then, we also investigated the influence factors of structures of these complexes, and explored their thermal stabilities and fluorescence properties. Furthermore, the Cd S nanoparticles were synthesized by the solvothermal method, and the preliminary attempt for photocatalytic hydrogen production of the loaded nano-Cd S also had been made.The dissertation includes two parts as follows:1. Seven new coordination complexes were synthesized under solvothermal condition in the presence of major ligand 2-aptt H and auxiliary ligand rigid aromatic carboxylic acids. [Cd2(2-aptt)2(1,4-bdc)(H2O)]n(1), {[Cd3(2-aptt)2(1,3-bdc)2]·4H2O}n(2) and {[Cd3(2-aptt)2(pma)]·3H2O}n(3) form 2D networks, while their structures are different due to the divesity of auxiliary ligand. [Zn3(2-aptt)2(1,4-bdc)2]n(4) shows a 3D framework, [Zn4(2-aptt)4(pma)2(4H2O)]n(5) features a 2D grid structure, [Zn2(2-aptt)2(3-pc)2(4H2O)](6) is a dinuclear structure, and [Pb(2-ptt)]n(2-ptt H2=3-(2-pyridyl)-1H-1,2,4-triazole-5-thione)(7) exhibits a 2D layer structure. It is worth noting that auxiliary ligand only adjusted the p H value and the ligand 2-aptt H was converted into 2-ptt H2 in complex 7. In addition, we discussed the influences of auxiliary ligand and metal ions on the structure of complexes, also investigated the thermal stabilities and solid-state fluorescence properties of complexes 1–6. Moreover, complexes 1 and 3 were used as precursor for the synthesis of Cd S nanoparticles. At the same time, the preparation of grapheme load with Cd S was carried out. Furthermore, the preliminary attempt of photocatalytic hydrogen production had been made.2. Five coordination complexes based on 4-Sptta ligand have been successfully synthesized under hydrothermal/solvothermal conditions with different metal salts. These crystal structures are confirmed by single crystal X-ray diffraction. [Co2(4-sptta)4(2H2O)]n(8) is a 2D crown-shaped network, {[Zn2(4-sptta)4]·2H2O}n(9) shows a 2D grid structure,{[Cd(4-sptta)2(H2O)]·H2O}n(10) features 1D double-chain, [Pr(4-sptta)3(H2O)]n(11) exhibits a 1D chain, and [Ni(4-sptta)2(4H2O)](12) is a mononuclear structure. Furthermore, the thermal stabilities of 8–12 and solid-state fluorescence properties of 9–11 and ligand were also investigated. And the influences of metal ions and structures on the thermal stabilities and solid-state fluorescence properties were also discussed.