Synthesis And Antibacterial Activity Of Ferrocenyl Schiff Bases And Its Metal Complexes

Ferrocene and its derivatives have a series of characteristics, such asstability, low toxicity, biological oxidation, biological activity, hydrophobic,aromaticity and other characteristics. Hence, their derivatives and complexes willbecome an important role in the dyes, molecular electrnics, biological sciences,medicine and so on.Chalcone and its derivatives have a set of reaction centers, and wereregarded as important organic intermediates, and widely used in Michaeladdition, polymerization, photocycloaddition and supermolecular chemistry. As akind of versatile intermediates, chalcones have been used widely in the synthesisof organic compounds and medicines, and exhibited significant biologicalactivities, such as, antiviral, antifungal, antitumor, antibacterial activities andinhibiting the growth of weed.The Schiff bases from S-methyl（or benzyl）dithiocarbazate and theircomplexes have strongly antitumour and antivirus activities. Schiff bases havesome specialities due to its containing the azomethane group. Its N atom withseveral lone pair electrons p and sp2hybridized orbit is inclined to coordinatewith metals and to be ring formation. It seems significant in chemical andbiological field. Up to now, the researchers in the world have synthesized andcharacterized many kinds of Schiff bases and their metal complexes, and alsoexploited many uses such as medicines, catalyst, material and simulating biologymechanism. A new series of ferrocene-based Schiff bases were designed andsynthesized by the condensation of various ferrocene-based chalcones withS-benzyl dithiocarbazate, and the Schiff bases were coordinated with the metalion(M²⁺) respectively to form its metal complexes.Ferrocenylchalcone were synthesized by using substituted benzaldehyderespectively with acetylferrocene was based on Claisen-Schmidt condensation,using solid-phase method in grinding under solvent-free conditions offerrocenylchalcone. The novel ferrocene-based Schiff bases derivatives were obtained by reaction between above mentioned chalcones and S-benzyldithiocarbazate and oxygen-free N2atmosphere at refluxing. The abovecomplexes were characterized by elemental analysis, IR spectra, UV spectra,1^H-NMR,（13）^C-NMR. These twelve schiff bases（HL1, HL6, HL8, HL11） were usedto synthesize the complexes with transition metal ions (Zn²⁺, Pb²⁺, Cd²⁺, Ni²⁺), atlast sixteen metal complexes were synthesized by the Schiff bases coordinatedwith the metal ion respectively, the above complexes were characterized by IR,1^HNMR,（13）^CNMR,elemental analysis, and TGA.The12kinds of Schiff bases ligands’ antibacterial activity （Escherichia coil,Staphylococcus aureus, Saccharomyces cerevisiae）were tested. Studies exhibitedthat the antibacterial activity can be improved by replacing the halogen in thearyl, and the fluorinatin antibacterial has stronger ability than thechloro-Substituted aromatic compounds. Schiff bases ligands containing aheterocycle were showed better antibacterial activity.