Synthesis,Structure And Properties Of Ligands And Complexes Based On Pyrazolone And Methyl-carbazate

The design and synthesis of new ligands and their complexes based on pyrazol-5-one are one of the hot fields in the coordination chemistry, due to the fact that pyrazol-5-one is an important kind of five-number heterocyclic compounds and its derivatives and complexes have been widely used in functional materials, antibacterial reagents, pigments and metallurgy. Being a environment-friendly industrial chemicals, methyl carbazate has been the precursor of pesticide and medicine. However, it still remains a further development for the application of methyl carbazate in coordination chemistry. In this thesis, using 3-methyl-1-phenyl-5-pyrazolone and methyl carbazate as ligand to react with metal salts, the crystals of three ligands and 15 complexes have been obtained from normal crystal growth, and also characterized by single-crystal X-ray diffraction, powder X-ray diffraction, TGA, solid fluoresence and variable-temperature magnetic susceptibility.1. By changing relative position between amino-carboxyl-group and substitutes of benzoic acid, six compounds based on pyrazolone-azo-carboxybenzene were synthesized through coupling reaction with 3-methyl-l-phenyl-5-pyrazolone(PMP) or 3-methyl-5-pyrazolone(MP) as raw materials. X-ray single crystal diffraction analysis shows the molecular structure of some compounds is hydrazone-ketone form although the tautomerism of pyrazolone-azo-carboxybenzene. Two mono-schiff bases and one asymmetric bis-schiff base based on 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) were obtained with normal or microwave-assisting refluxing methors. NMR was also used to character the compounds.2. Ten complexes have been synthesized successfully by the reaction of Cu(Ⅱ)/Co(Ⅱ)/Ni(Ⅱ) ions and the above ligands. Different structures from mononuclear to 1-D chains have been found in these complexes. The crystal structures of the azo complexes show the ligands coordinated the metal ions in azo-enol isomer. The different electrophilic effect of substitute groups connecting with carboxybenzene may influence the final structure of complexes. It is the first time to report the azo complexes with helix chain. Studies on the thermal stabilities, magnetic properties, optical properties and DNA cleavage reactions of some compounds were also performed in our work. Two complexes were achieved from the Schiff base ligand(Hapmbp) and Co(Ⅱ)/Ni(Ⅱ) ions. Both of them were determined by the single crystal X-ray studies and reveals that the two adopt distorted octahedral conformation. However the deviation of complex 10 from ideal octahedral is more serious than 9, which leads to a red shift peak of complex 10 in the fluorescent spectra with respect to complex 9. The solid fluorescent spectra also reveals that there is an obvious difference between the spectra of the ligand and its complexes and the fluorescence intencisity of complex 9 is stronger than the other two compounds.3. Five complexes were synthesized with methyl carbazate under different ancillary ligand assistant. The complex 12 and 13 were obtained by in-situ reaction and the reacting mechanisms were also discussed. The adjacent Co(Ⅱ) are connected by the two carbonyl groups in one ligand and each Co(Ⅱ) is surrounded by for carbonyl groups from four ligands. Complex 13 processes layered structure built from [Co(tadd)2]n chains and two sets of layers interpenetrate to each other and generate a three-dimensional (3D) inclined polycatenated net. Compared with the related bpys, nearly 100% fluorescence emission quenching in the complex is observed. Magnetic property of compound 13 reveals a weak antiferromagnetic coupling between the Co(Ⅱ) centers for the long distance mediated by the urazole-bridges.