Luminescence behavior of Eu3+ with thenoyltrifluoroacetonate, sulfoxides and macrocyclics

In this work we present a study of the luminescence intensity of Eu(TTA)3.xL, where TTA=thenoyltrifluoroacetonate (L denotes DBSO and PTSO sulfoxides, and derivatives of 15C5 and 18C6 macrocyclics). The complexes with 15-crown-5 ether ligand contain two H2O molecules. The complexes were characterized by a microanalytical procedure, IR spectroscopy and molar conductance. They show high luminescence mainly in the red region. The characteristic emission spectra of Eu3+ in these compounds show uncommonly high values of the Ω2 intensity parameters, reflecting the hypersensitive behavior of the 5D0→7F2 transition and indicating that the rare earth ion is in a highly polarizable chemical environment. The 5D0→7F0 transition splitting, in the case of Eu(TTA)3.18C6, indicates more than one site of symmetry occupied by Eu3+. (orig.)