Photoacoustic spectra of complexes of tryptophan with Sm(III), Tb(III) and Dy(III)

Abstract

Crystals of the complexes of Tryptophan with Sm(III), Tb(III) and Dy(III) were synthesized and the photoacoustic (PA) spectra in the UV–vis region were recorded. The PA intensities of the central lanthanide ions are interpreted in terms of the probability of nonradiative transitions. It is found that the PA intensity of the ligand bears a relation to the intramolecular energy transfer process. For the title complexes, the different PA intensities of the ligand, tryptophan, are interpreted by comparison with the fluorescence spectra. The relaxation process models are also studied based on the PA and fluorescence spectra.