For the first time, we observed photoluminescence in Eu(III) dithiocarbamate complexes at room temperature -- more specifically in [Eu(Et(2)NCS(2))(3)phen], [Eu(Et(2)NCS(2))(3)bpy] and the novel [Eu(Ph(2)NCS(2))(3)phen], where phen stands for 1,10-phenanthroline and bpy for 2,2'-bipyridine. Correlations between the electronic structure of the dithiocarbamate ligands on one hand, and covalency, intensity, and ligand field spectroscopic parameters on the other, could be established. Moreover, the relative values of the emission quantum efficiencies obtained for these complexes, as well as their dependence with temperature, could be satisfactorily described by a theoretical methodology recently developed.

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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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The design of bifunctional magnetic luminescent nanomaterials containing Fe3O4 functionalized with rare earth ion complexes of calixarene and β-diketonate ligands is reported. Their preparation is accessible through a facile one-pot method. These novel Fe3O4@calix-Eu(TTA) (TTA = thenoyltrifluoroacetonate) and Fe3O4@calix-Tb(ACAC) (ACAC = acetylacetonate) magnetic luminescent nanomaterials show interesting superparamagnetic and photonic properties. The magnetic properties (M-H and ZFC/FC measurements) at temperatures of 5 and 300 K were explored to investigate the extent of coating and the crystallinity effect on the saturation magnetization values and blocking temperatures. Even though magnetite is a strong luminescence quencher, the coating of the Fe3O4 nanoparticles with synthetically functionalized rare earth complexes has overcome this difficulty. The intramolecular energy transfer from the T1 excited triplet states of TTA and ACAC ligands to the emitting levels of Eu(3+) and Tb(3+) in the nanomaterials and emission efficiencies are presented and discussed, as well as the structural conclusions from the values of the 4f-4f intensity parameters in the case of the Eu(3+) ion. These novel nanomaterials may act as the emitting layer for the red and green light for magnetic light-converting molecular devices (MLCMDs).

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