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) dihydrated 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 3 1 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 and h) 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.

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Two new bis(dipivaloylmethanate)nitrato-bis(triphenylphosphine oxide)lanthanide(III) complexes [Eu(dpm) 2 (NO 3 )-(tppo) 2 ] (1) and [Tb(dpm) 2 (NO 3 )(tppo) 2 ] have been prepared in monomeric form. The structural behavior of these coordination compounds is significantly different from those of [Eu 2 (dpm) 6 ] and [Tb 2 (dpm) 6 ] dimeric complexes. The photoluminescent properties of the monomeric and dimeric complexes are dependent on the energy positions of the low-lying ligand-to-metal charge-transfer (LMCT) state, which may be correlated with the chelating and chelate bridging [a]

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