Synthesis, Characterization And Application Of New Schiff Base Complexes

Schiff base and its complexes are widely used in the fields of biology, catalysis and material. The study of them is focus of the study of coordination chemistry. So, prepare new Schiff base complexes and study their properties and application are of important significance to the development of coordination chemistry.Eleven new Schiff base ligands which were derived from 5-chloro-2-hydroxybenzo-phenone-o-phenylenediamine-salicylaldehyde(H2L1),5-chloro-2-hydroxybenzophenone-o-phenylenediamine-2-hydroxy-1 -naphthaldehyde(H2L2 ),5-chloro-2-hydroxybenzophenone-o-phenylenediamine-o-vanillin(H2L3), salicylidene-L-lysine-2-hydroxy-1 -naphthaldehyde (H2L4Li), salicylidene-L4ysine-furfural(HL5Li),o-vanillin--L-lysine-salicylidene(H2L6Li), o-vanillin~L-lysine-2-hydroxy-1 -naphthaldehyde(H2L7Li), 2-hydroxy-1 -naphthaldehyde-4-aminoantipyrine( HL8), furfural-4-aminoantipyrine( L9 ), 2-hydroxy-1-naphthaldehy-demethionine(KL10) and o-vanillin-L-tyrosine(KL11)have been synthesized, and thirty nine coordination compounds of lanthanide nitrates or transition metal with these ligands have been synthesized. All these complexes are first reported by author. These ligands and complexes were characterized by elemental analysis, mass spectra analysis, IR spectra, UV spectra ,'HNMR, TG-DTG, x-ray powder diffraction and molar conductance analysis. The antibacterial activity and the catalytic activity of some complexes have been studied.In these Schiff base ligands, there are seven types of novel unsymmetrical ones(H2L4Li, HL5Li, H2L6Li, H2L7Li, H2L', H2L2, H2L3) from L-lysine or 1,2-diaminobenzene.The compositions of the metal complexes of with unsymmetrical Schiff base ligands from 1,2-diaminobenzene were confirmed to be [ML1] xH2O (M=Cu, x=O; M=Nk Mn ,Co ;x=1;M=Zn,n=3);[Ln(HL1)(NO3)2(H2O)]-H2O (Ln=La,Nd,Pr); [ML2]xH2O (M=Mn, x=1; M=Co, x=0); [Ln(HL3)(NO3)2(H2O)]-2H2O (Ln = La, Er, Pr, Gd,) The compositions of the Ln((III) complexes with unsymmetrical Schiff base ligands from L-lysine were confirmed to be [LnH2L4(NO3)]NO3-2H2O , [LnHL5(NO3)] NO3-2H2O, [LnH2L6(NO3)] NO3-2H2O and [LnH2L7(NO3)]NO3-2H2O (Ln=La, Er, Gd, Sm, Ho,Tm) .The compositions of the Ln((III) complexes with 2-hydroxy-1- naphthaldehyde-4-aminoantipyrine and furfural-4-aminoantipyrine were confirmed to be [Ln(HL )(C2H5OH)(H2O)2]NO3 (Ln=Gd, Eu) , [Ln(L9)(CH3OH)(NO3)3]H2O (Ln=Eu, La, Pr) .The compositions of the Ln((III) complexes with potassium salt of 2-hydroxy-l-naphthaldehyde-methionine and phenanthroline(phen) confirmed to be [LnL10 (phen) (NO3) (H2O)]NO3 (Ln=Gd, Dy, En Yb) .The compositions of the Ln(III) complexes with potassium salt of o-vanillin-L-tyrosine and phenanthroline(phen) confirmed to be [LnL11 (phen) (H2O)] (NO3)2 (Ln-La, Er) .The synthesis of ligands and complexes was in non-aqueous solvents. The solid complexes could be gained by using mixed solvent when the complexes were precipitated difficultly. The complexes were all stable and could be preserved in the air for a long time. The complexes were colored and powered substances. The properties of the Ln(III)complexes was similar.The ligands synthesized are chelating agent. The nitrogen atom of Schiff base, oxygen atom of hydroxybenzene, methoxide, carboxyl and the oxygen atom in the furan ring were all coordinated to the metal ions. Water molecules are coordinated or lied in crystal substances. The nitrate ions are within the coordination sphere or not coordinated. Carboxyl and nitrate ions are coordinated to the metal ions in a mondentate or bidentate fashion.Combinating Achar differential and Coats-Redfern integral method which fits the thirty kinetic equations, the calculating program was designed. The kinetic equations of thermal decomposition for complexes and the corresponding kinetic parameters were gained. The kinetic parameters include E, A, order of reaction and correlation coefficient, etc. The activation entropy AS" and activation free-energy AG* for some thermal decomposition stage were also gained.The thermal decomposition kinetic function of [La(HL3)(NO3)2( H2O)]-2H2O in step(2) may be expr...