Of ¦Â-diketone Reduction Aromatic Amine Schiff Base Transition Metal Complexes Synthesis, Characterization, Reaction Mechanism, Structure And Performance

Schiff bases and their complexes have many good functions that they can used as chelate reagent, stabilizer, bioactive reagent and catalyst etc that widely used in the study of many science fields such as chemistry , biology, and medicine etc and chemical industrial produce. Therefore more and more people pay high attention to the study of these compouds' synthesis and functions. Now, the research of them have become an extraordinary active topic in the chemical field. In this paper, progress in studies on the Schiff bases and their complexes, the transition metal elements" importance to life and people's health have been summarized. And the reaction mechanism of the Schiff base and the synthesis of their complexes have been studied systematically.We synthesized six Schiff base ligands derived from hexafluoroacetylacetone (HFAA)with 4-aniinoantipyrine , l-benyl-3-methyl-4-benzoyl-pyrazolin-5-one(PMBP) with aminophenol (o-,m-,p-) and naphthylamme (a-,β-) and their twenty-one transition metal complexes. All of them are not reported in the literature. We inferred their possible structures from the determination of elemental analysis, IR and UR spectral analysis. And discussed the reaction mechanism of Schiff base derived from these two β-diketone in great detail.The single crystal structures of three Schiff base ligands derived from HFAA with 4-aminoantipyrine, PMBP with o-aminophenol, PMBP with a-naphthylamine and its Co(Il) complex have been received and determined by X-ray diffraction. The characterization of these compounds is identical with the determination of crystal structure. The analysis of their structures indicates that the Schiff base ligands derived from β-diketone are exist stably in crystal with enamine-ketone form and they are inune-enol form when they coordinate with metals.The bioactivitives of the six Schiff base ligands and their complexes were tested at different concentrations by single paper disc method. Comparative studies on the antimicrobial activities of these compounds were performed. The result shows that the six Schiff base ligands and their complexes all have good inhibitory effect to Escherichia coli and Staphylococcus aureus. And we discussed their possible antibacterial mechanism.The quantum chemical calculations of HFAA, PMBP and three Schiff base ligands derived from them whose crystal structures have been determined were performed using Gaussian94 programme on computer. We discussed the relationship between structure and functions, especially, the biological activities. The analytical results from the quantum chemical descriptors indicate that they have good coordinating ability and antibacterial activity , which accord with the results of experiments. These cases provide important basis for the future research.