Synthesis, characterization and spectroscopy of lanthanide picrate complexes with o-(benzylsulfinyl)methylbenzoate

Abstract

Complexes of the general formula (Ln(pic) 3·2.5(BSMB) (Ln=La, Ce, Nd, Sm, Eu, Tb and Er; pic=picrate, BSMB= o-(benzylsulfinyl)methylbenzoate) were prepared. The characterization of the ligand and complexes were carried out by CHN elemental analyses, lanthanide titration with EDTA, IR absorption spectroscopy, conductance measurements and emission spectroscopy (for the Eu and Sm adducts). Conductance measurements, indicate a non electrolyte behavior. The SO stretching mode is shifted to lower energies, with respect to the neat ligand, evidencing coordination through the SO group. IR data also suggest that the picrate anions are bidentate, coordinated though the phenolic and one o-nitrogroup oxygens. The transition 5D 0→ 5F 0,1,2 for europium and 4G 5/2→ 6G 5/2,7/2,9/2 for samarium with broad, non-resolved peaks, yield evidence of the polymeric nature of these complexes.