Luminescence investigation of the Sm(III)-b-diketonates with sulfoxides, phosphine oxides and amides ligands.

Abstract

In this paper we report on a photoluminescent investigation of complexes involving Sm -b-diketonates with sulfoxides, phosphine oxides and amides ligands. In the synthesis of the coordination compounds we used samarium tris(thenoyltrifluoroacetonate) dehydrated precursor with the following ligands (L): DBSO and PTSO sulfoxides; TPPO phosphine oxide and (PHA) N-phenylacetamide. They have 31 31 shown high orange luminescence characteristic of the Sm ion. The emission spectra of the Sm -complexes present narrow bands 4 6 4 6 arising from the G →H (J55/ 2, 7/ 2, 9/ 2, 11/2) transitions with the hypersensitive G →H transition as a prominent group. It 5 / 2 J 5 / 2 9/ 2 4 31 is observed an efficient intramolecular energy transfer from the triplet state (T) of the ligands to the emitting G state of the Sm ion. 5 / 2 The experimental intensity parameters (h andh ) for the Sm and Eu complexes have been determined and compared. The lifetimes (t ) Sm Eu 4 of the emitting level G of the Sm-complexes are approximately 10 times higher than in the precursor compound [Sm(TTA) ?(H O) ] 5 / 2 3 2 2 indicating that radiative processes are operative in all the compounds due to the absence of multiphonon relaxation by coupling with the OH oscillators.