Spectral Study of the Co‐luminescence Effect of Lanthanide Ternary Complexes with Benzoic Acid and Phenanthroline

Abstract

The photoacoustic (PAS) spectra and luminescence spectra of Eu(Hba)3 Phen and coprecipitates Eu0.6Ln0.4(Hba)3 Phen complexes (Ln3+:Y3+, Nd3+; Hba: benzoic acid; Phen: phenanthroline) have been measured, and the co‐luminescence effect of the coprecipitates are reported. The PAS intensities of the central lanthanide ions are interpreted in terms of the probability of nonradiative transitions. It is found that the PAS intensity of the ligand bears a relationship with the energy transfer processes. The PAS intensity in the region of ligand absorption increases in the order of Eu0.6Nd0.4(Hba)3 Phen > Eu(Hba)3 Phen > Eu0.6Y0.4(Hba)3 Phen, which indicates that addition of the second lanthanide ions in each case changes the relaxation processes of the complexes. The energy transfer and relaxation processes are discussed in combination with the luminescence spectra.