Synthesis And Structure Characterization Of MOFs Constructed By Carboxylic Acids And Ligands With N Atoms

MOFs are a type of self-assembly formed by organic ligands and metal ions. They are a new type of solid material, which have an extensive application prospect in the fields of optic materials, gas-saving materials and catalyzers.In this thesis, 9 MOFs with novel structures were hydrothermally synthesized. The structures and thermal stabilizations of the coordination polymers were characterized by many kinds of analysis methods, such as infrared spectra, X-ray single crystal diffraction and thermal gravity analysis.(â… )Three kinds of MOFs whose ligands were succinic acid and ligands with N atoms including Im, 4,4'-bipy and Phen were synthesized by evaporated crystallization method and hydrothermal method: (1)[Cu(succinic acid)(Im)₂]_n,(2)[Cd(succinic acid)(4,4'-bipy)]_n,(3){[Cu₂(succinic acid)(Phen)2(H₂O)2](NO₃)₂}_n, where the coordination number of Cu²⁺ is four, and of Cd²⁺ is six. Carboxylic acid and ligands with N atoms were used together to synthesize complicated structures, which conquered the shortcoming of the ligands with N atoms that may cause the unstability of the MOFs.(â…¡) Three kinds of MOFs whose ligands were aromatic carboxylic acids including BTC and 1,3-BDC and ligands with N atoms including 2,2'-bipy and Phen were synthesized by hydrothermal method: (4)[Zn(BTC)(2,2'-bipy)(H₂O)]_n ,(5)[Cd₂(1,3-BDC)₂(Phen)₂]_n , (6)[Zn₇(BTC)₄(2,2'-bipy)₄(OH)₂]_n, where the coordination numbers of Zn²⁺ is five and six, and the coordination number of Cd²⁺ is six. 2,2'-bipy and Phen are inclind to be chelated with metallic cations, and in these three MOFs they are all chelating coordinated.(â…¢) Three kinds of MOFs whose ligands were aromatic carboxylic acid including NTC, 1,3-BDC and BTC and ligands with N atoms including Im, Phen and 2,2'-bipy were synthesized by evaporated crystallization method and hydrothermal method: (7)[Cu₂(Im)₁₀·10NTC·3H₂O]_n , (8)[Co(succinic acid)(H₂O)₄]_n ,(9)[Zn(Isonicotinic acid)2(H₂O)4]_n, where the coordination numbers of Cu²⁺ is five, of Co²⁺ is five, and of Cd²⁺ is six. These three MOFs formed three dimensional structures by hydrogen bonds andÏ€-Ï€interactions.