Phosphorescence of complexes of some elements of group 3 with β-diketones at room temperature

The luminescence and phosphorescence spectra (excited by uv radiation) of the complexes of Gd with acetylacetone, Bz2CH2, and thenoyltrifluoroacetone (TTA) as well as La, Y, and Sc with TTA were obtained. The samples were measured as adsorbates on a filter paper, which was dried, after loading the components (the elements as chloride solutions, β-diketones as 0.1M EtOH or Me2CO solutions), at less than or equal to 1000 for 30 minutes. The phosphorescence was observed in each 2.5 μsec after illuminating the sample. The absorption maximum of the luminescence and phosphorescence spectra are given. The most intense luminescence was observed for the Gd and Y complexes with TTA. By keeping the complexes in a moist atmosphere, the luminescence disappeared in 20-30 min and reappeared after repeatedly drying the sample. The quenching was of an exponential character. The obtained tau values (approximately 0.2 μsec)were, with the exception of the complex of Gd with TTA (tau = 1.9 μsec), considerably lower than those from literature, for vitreous solutions of complexes at 770K. Visually, the luminescences were recorded for the contentsof Gd 0.1, La, Lu, and Y 2, and Sc 20μg/0.02 ml