Synthesis, characterization, and antioxidative action of lanthanide complexes of N-benzoylacetoneglycine

N-Benzoylacetoneglycine behaving as an unstable monobasic tridentate ligand has been isolated in the stabler sodium salt which has been used to prepar e the corresponding lanthanide(III) complexes. The complexes have been char acterized by elemental analysis, molar conductance, thermal analysis, and s pectral data. beta-Ketoenamine structure of the ligand and the bonding in t he lanthanide chelates have been discussed on the basis of IR and H-1 NMR s pectral data. The nephelauxetic ratio (beta), bonding parameter (b(1/2)), a nd Sinha's covalence parameter (delta) reflect obvious covalent nature for the complexes. Both the lanthanide complexes and sodium salt of N-benzoylac etoneglycine are good antioxidants.