Synthesis Of Symmetrical Double Schiff Base And Its Complexes

Schiff base is the compound containing an C=N bond which dehydrated by thecarbonyl in aldehyde or ketone molecules and amino in the amine molecules. In recentyears, Schiff base and its complexes are widely used in photochromic, catalysis,medicine, analysis of detection and other fields. There are various kinds of Schiff base,such as single, double Schiff, macrocyclic Schiff base and other types of Schiffbase.Symmetrical double Schiff base plays an important role in coordination chemistrybecause of its special structure.o-diaminobenzene condens salicylaldehyde Schiff base (L3), Schiff base (L2) issynthesis by o-diaminobenzene and ethanediamine,Preparation of o-diaminobenzenecondens thiosemicarbazide Schiff base (L) are synthetized in this paper. And then16metal complexes were synthesized by the three Schiff bases with transition metal salts.Schiff base ligand L3was synthetized by using o-diaminobenzene andsalicylaldehyde as reaction monomers.Then4metal complexes were synthesized byL3and Cu (Ⅱ)、Ni(Ⅱ)、Mn(Ⅱ)、Cd(Ⅱ). Reaction conditions were optimized in thispaper. The results are as follows: reaction temperature at45℃,reaction time4hours.The ligand and metal complexes were characterized by IR, UV.Schiff base ligand L2was synthetized by using o-diaminobenzene andethanediamine as reaction monomers.Then4metal complexes were synthesized by L3and Cu (Ⅱ)、Ni(Ⅱ)、Mn(Ⅱ)、Cd(Ⅱ). Reaction conditions were optimized in this paper.The results are as follows: reaction temperature at40℃；reaction time6hours and useAcetic acid as Catalyst. Schiff base ligand and structure of complexes werecharacterized by IR.A novel double symmetrical connection structure Schiff base ligand L was synthetized by using o-diaminobenzene and thiosemicarbazide as reaction monomers.The reaction time is determined as4hours by TLC tracking reaction progress. Thereaction temperature is40℃.And the solvent is methanol mix with water(4:1). Tenmetal complexes were synthesized by the ligands of L and Cu(II), Ni(II), Mn(II),Co(II), Zn (II)5kinds of metal salt that includes five kinds of metal elements and threekinds of anion. The double symmetrical connection structure of ligand and thestructure complex were proved by IR, UV, NMR. Bacteriostatic test were carryed outon ligand L and its nickel complexes, which proved that it has certain antibacterialactivity.Schiff base ligand synthetized in this paper and its transition metal complex hasgood practical application prospect.