Synthesis, Characterization and Antioxidative Activity of Lanthanide Complexes with 3,5-Dibenzyloxybenzoyl-2,4-Dihydroxybenzaldehyde-Hydrazone
来源期刊：JOURNAL OF RARE EARTHS2003年第5期
论文作者：张玲 谭民裕 房建国 唐宁
Key words：inorganic chemistry; hydrazone complexes; characterization; antioxidative activity; rare earths;
Abstract: In order to study the coordination character of the rare earth elements with hydrazones and the antioxidative activity of the ligand and the complexes, 3,5-dibenzyloxybenzoyl-2,4-dihydroxybenzaldehyde hydrazone (H2L), a new chelating ligand, and its six lanthanide complexes, Ln (HL)(OAc)2*n H2O [Ln=La(Ⅲ), Sm(Ⅲ), Eu(Ⅲ), Gd(Ⅲ), Tb(Ⅲ), Dy(Ⅲ); n=2, 4, 5], were synthesized and characterized on the basis of elemental analyses, IR and 1H NMR spectra, molar conductivity. The results show that the lanthanide ions are coordinated by O, O and N donors of the phenol (Ar-OH(A)) without deprotonation, the enol oxygen of the hydrazone group (NCO-) and the azomethine group (CH=N) from the ligand respectively, and by the four carboxylic oxygen from two acetate groups (CH3COO-) in the bidentate form. The scavenging activity of the ligand and the six lanthanides complexes on the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radicals is also evaluated. The results show that both the ligand and the complexes have the scavenging activity on the DPPH radicals, and the scavenging activity of the complexes is better than the ligand.
张玲1，谭民裕1，房建国1，唐宁1
(1.College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China)
Abstract:In order to study the coordination character of the rare earth elements with hydrazones and the antioxidative activity of the ligand and the complexes, 3,5-dibenzyloxybenzoyl-2,4-dihydroxybenzaldehyde hydrazone (H2L), a new chelating ligand, and its six lanthanide complexes, Ln (HL)(OAc)2*n H2O [Ln=La(Ⅲ), Sm(Ⅲ), Eu(Ⅲ), Gd(Ⅲ), Tb(Ⅲ), Dy(Ⅲ); n=2, 4, 5], were synthesized and characterized on the basis of elemental analyses, IR and 1H NMR spectra, molar conductivity. The results show that the lanthanide ions are coordinated by O, O and N donors of the phenol (Ar-OH(A)) without deprotonation, the enol oxygen of the hydrazone group (NCO-) and the azomethine group (CH=N) from the ligand respectively, and by the four carboxylic oxygen from two acetate groups (CH3COO-) in the bidentate form. The scavenging activity of the ligand and the six lanthanides complexes on the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radicals is also evaluated. The results show that both the ligand and the complexes have the scavenging activity on the DPPH radicals, and the scavenging activity of the complexes is better than the ligand.
Key words:inorganic chemistry; hydrazone complexes; characterization; antioxidative activity; rare earths;
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