PHOTOACOUSTIC SPECTRA OF COMPLEXES OF TRYPTOPHAN WITH SM(III), TB(III) AND DY(III)

Crystals of the complexes of Tryptophan with Sm(III), Tb(III) and Dy(I II) were synthesized and the photoacoustic (PA) spectra in the UV-vis region were recorded. The PA intensities of the central lanthanide ion s are interpreted in terms of the probability of nonradiative transiti ons. 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 interpre ted by comparison with the fluorescence spectra. The relaxation proces s models are also studied based on the PA and fluorescence spectra. (C ) 1998 Elsevier Science B.V. All rights reserved.