Spectral aspects and biological application of rare earth complexes with azomethines

The azomethines1-[(2-hydroxyphenyl)-1-N-phenylamino] hydrazine-carboxamide (HO^capN^capOH) and 2-hydroxy-N-phenyl benzamide benzothiazoline (HO^capN^capSH) have been synthesized by the condensation of 2-hydroxy-N-phenylbenzamide with semicarbazide hydrochloride and 2-aminothiophenol, respectively. The new derivatives have been prepared by the reactions with hydrated lanthanide chlorides. Elemental analysis suggest that the complexes have 1:2 stoichiometry and they were characterized further by magnetic moment, i.r, e.s.r., uv-vis and ¹H n.m.r spectral studies. The spectral studies confirmed the proposed framework of the new lanthanide complexes and indicated an octahedral geometry around the central metal atom. The free ligands and their metal complexes have been tested in vitro against a number of microorganisms in order to assess their antimicrobial properties. Both the ligands and their complexes were found to possess appreciable fungicidal and bactericidal properties.