Study On Complexes Of Novel Pyrazole Carboxylic Derivatives:Synthesis And Properties

Recently, considerable research efforts have been directed towards the pyrazole derivatives and their complexes not only because of their fascinating structural diversities, but also due to their potential applications in ion exchange, biological activities, magnetic, porous materials, catalysts, and luminescent materials. In additional, N-heterocyclic pyrazole derivativesis a good example of N-and O-donors ligands and regarded as one kind of elegant ligands to build the supramolecular complex structures. Based on the background and development of current researches, taken 8 novel pyrazole-carboxylic acids as ligands,23 novel complexes were designed and constructed in this thesis. Crystal structures were determined by single crystal diffraction method to determine structures of the complexes, and investigated properties of the complexes. The detail contents as follows:（1） Taken 1H-pyrazole-3-carboxylic acid （H₂L¹） and ethyl 1-（2-ethoxy-2-oxoethyl）-1H-pyrazole-3-carboxylate （epzc） as ligands to synthesize complexes. Three complexes [Co（HL¹）₂（H₂O）₂] （1）, [Ni₂L₂（H₂O）₆]-H₂O （2）, [Cu₂（L¹）₂]_n （3） were obtained from H₂L¹ and the transition metal ions, where 1 is mononuclear,2 is dinuclear and 3 is 2D network. The ligand epzc was resulted from H₂L¹ through the reaction of N-alkylation. Epzc and the transition metal ions gave three complexes [Ni（L₂）（H₂O）₄] （4）, [Cu₂（L²）₂（H₂O）₄] （5）, [Co₂（L²）₂（H₂O）₄]n （6） by one pot in-situ hydrothermal hydrolysis, where H₂L₂ is 1-（carboxymethyl）-1H-pyrazole-3-carboxylic acid. As same as complexes 1-3,4 is mononuclear, 5 is dinuclear and 6 is 2D network, respectively. Electroluminescent （ECL） properties were also studied of these six complexes and found that they could apply in luminescent materials.（2） Taken 2,2-di（1H-pyrazol-1-yl）acetic acid （H₂L₃） and di（1H-pyrazol-1-yl）methane （L⁴） to synthesize complexes. HL³ reacted with transition metal ions resulting four complexes {[Mn₂（L³）₂（OAC）₂]·2H₂O}_n （7）,{[Cd_1.5（L³）₂]ClO₄·H₂O}_n （8）, [Cu（L³）₂] （9）, [Co（L³）₂] （10） by the solution method. While instead of solvothermal method, three different complexes obtained [Mn₂（L⁴）₂Cl₄]n（11）, [Cd₂（L⁴）₂Cl₄]_n（12）, [Cu₂（L⁴）Cl₂]n （13）, where L⁴ was decarboxylated form HL³. Di（1H-pyrazol-l-yl）methane （L⁴） was synthesized to compare in same condition, however, four new complexes [Mn_1.5（L⁴）（MeCN）Cl₃]n （14）, [Cd（L⁴）2H₂O]·ClO₄ （15）, [Co（L⁴）2H₂O]·ClO₄ （16） were isolated. In this section, fluorescence properties were studied on 7-16, magnetic property on 10, and Hirshfeld surfaces analysis on 14-16.（3） Three complexes [Cu（HL⁵）₂（H₂O）₂] （17）, [AgHL⁵]n （18）, [Co₂（HL⁶）₂Cl₂（H₂O）₄]Cl₂-H₂O （19） from the reaction of 5-methyl-1-（1H-pyrazol-3-yl）-1H-1,2,3-triazole-4-carboxylic acid （H₂L⁵） and Cu（II）, Ag（II） and Co（II）. Decarboxylation occurred in 19 and resulted a new ligand 5-methyl-1-（1H-pyrazol-3-yl）-1H-1,2,3-triazole （HL⁶）. [Ni（HL⁷）₂]_n （20） is a 2D polymer, where HL⁶ is 5-（pyridin-4-yl）-1H-pyrazole-3-carboxylic acid. Taken 1H-pyrazole-4-carboxylic acid （H₂L⁸） as directed ligand and constructed three 3D MOFs, [Zn₄（μ4-O）（μ4-L⁸）₃]_n （21）, {[Zn₂（L⁸）₂（4,4’-bipy）]·2H₂O}n and{[La（HL⁸）₂NO₃]}_n （23）. In this section, we investigated fluorescence properties of complexes 18,19, supercapacitor of 20, ECL of 21, and topological structures of 22,23.