Synthesis, Characterization And Propetries Of New Schiff Bases

Schiff base containing an imine group (>C=N–) is a kind of important compound.The synthetic steps are relatively easy, by changing the substituent group of thereagent, we can synthesize a lot of Schiff bases which have different structures andshow different properties. Schiff bases can be divided into single Schiff base,symmetric and asymmetric Schiff base, macrocyclic Schiff base and Schiff basepolymer according to its structure. Base on the different types of reactants, we candivide Schiff bases into amino acid Schiff base, sulfonamides Schiff base,N-salicylideneaniline Schiff base and so on. The metal ions of Schiff base complexescontain transition element, lanthanide and even actinide elements. The studies aboutstructure of Schiff base complexes involve mononuclear, dinuclear, polynuclearcomplexes.N atom has lone pair electron which makes imine group easy to form complexeswith most of metal ions. Schiff bases and Schiff base complexes are suitable for thesimulation study of living organisms, because the structures of them are close to thetruth of the life system. At the same time, the unique structure and good performanceof Schiff bases and its complexes have caused wide public concern and research in thefields of metal antiseptic, functional materials, catalyst and analytical chemistry.Some compounds containing a–N=N–group are referred to azobenzenecompound. It is well known that–N=N–group can undergo trans-cis-transisomerization cycles under the irradiation at the wavelength lying in the absorptionregion. Based on photoinduced birefringence, azobenzene compounds receivedunprecedented attention in the field of nonlinear optical material, holographic grating,liquid crystal material and optical storage materials.The paper mainly involves three aspects as following1.3,3′-Azobenzaldehyde and3,3′-Azoxybenzaldehyde were synthesized from3-nitrobenzaldehyde though protection of ethylene glycol, reduction by Mg anddeprotection.2. Eight Schiff base derivatives containing an azo or azoxy groups were designed and synthesized from anthranilamide, sulfanilamide, o-aminophenol and4-(4-Tolyl)-3-thiosemicarbazide. Four macrocyclic compounds were synthesized fromlysine and cystine. The newly synthesized compounds were characterized by FT-IR,1H NMR, MS and elemental analysis.3. We studied the optical properties, ion recognitions and antiproliferativeactivities against Hela cell lines of compounds4a-7a,4b-7b. Under the irradiation of365nm light, all of the compounds can realize the trans-cis-trans isomerization.Fluorescence spectrum studies showed that compound4b have selective recognitionto Os(IV) and UV spectrum studies showed that compounds5a and5b have selectiveresponse to Cu(II). All compounds had different degree of inhibition to Hela cells,Compounds4a,6a,6b were found to exhibit strong cytotoxic activity.