Synthesis Of Schiff Base From Pmbp Schiff Bases And Their Metal Complexes, Characterization, Crystal Structure, Antibacterial Activity And Quantum Chemistry Research

Rencently, one important branch of pharmaceutical chemistry——synthesis and research of the Schiffbases and their metal complexes have attracted many attentions. Some of them have not only anticancer, tumour activity, but also antibacterial activity. Research and exploitation of the Schiff bases'antibacterial activity is very important. Amino acid esters and compounds containing fluorin atoms have some characteristic, especially in pharmaceutical chemistry, In this study, three kinds of Schiff bases derived from PMBP with L-alanine methyl ester, L-alanine methyl ester, L-valine methyl ester, p-fluorobenzylamine and their metal complexes were synthesized. Elemetal analysis, IR, UV of them were performed and the possible structures of these compounds have also been estimated.X-ray diffractions of two Schiff bases derived from PMBP with L-alanine methyl ester, p-fluorobenzylamine indicate that they are neutral ligands in an enamine-keto form. Ni complex 3 was synthesized by the reaction of Ni(Ac)₂ and PMBP- p-fluorobenzylamine. The crystal structure shows that the enamine-keto form in the ligand turns to imine form in the Ni complex.The antibacterial activity tests of Schiff bases and the complexes at different concentrations against E.Cocli and S.Aures were performed using disc diffusion method. The results reveal that almost all compounds have the activity of inhibiting the growth of the two bacterium, especially for PMBP- Amino acid esters.Quantum chemistry calculations method was performed on three compounds 1 to 3. The possible reaction mechanism of the Schiff bases' formation was discussed, and the relationship between structure and antibacterial activity has also been studied. This work may fufill the theory basis in future researches.