X-RAY PHOTOELECTRON-SPECTRA OF SOME BIOINORGANIC COMPLEXES OF THE RARE-EARTHS WITH N-ACETYLALANINE

Abstract X-Ray photoelectron spectra of some bioinorganic complexes of La, Ce, Pr, Nd, Sm and Eu with N -acetylalanine have been measured and the 3 d 5 2 and 3 d 3 2 main peaks and their satellites have also been assigned. The spin—orbit splitting between the 3 d 5 2 and 3 d 3 2 core-level of the rare earth ion in these complexes becomes slightly larger than that of the free rare earth atom due to the effect of the crystal field. The satellite for the 3 d main peaks of La in the solid state complex are in higher binding energy region and may be attributable to the L → 4ƒ charge-transfer shake-up process. The satellites for the 3 d main peaks of Ce, Pr, Nd, Sm and Eu are in the lower binding energy region and may be attributable to the 4ƒ→ L charge-transfer shake-down process.