INFLUENCE ON LUMINESCENT PROPERTIES OF THE AGGREGATE STATE OF LANTHANIDE β-DIKETONATES

Abstract

The complexes Eu3+ and Tb3+ with thienyl, phenyl and alkyl derivatives of acetylacetone with different chain length and the structure of the fl uorinated substituent (RF) were studied. In accordance with the triplet levels of β-diketones, in the complexes the energy transfer from them to the Eu3+ ion is possible with all the reagents used, and to the Tb3+ ion only in complexes with the phenyl and alkyl derivatives of acetylacetone. The intensity of the luminescence of Eu3+ and Tb3+ complexes is found to increase in solutions in the transition from non-fl uorinated β-diketones to fluorinated ones and also with the extension of RF: CF3–C3F7–C6F13–C8F17. However, in the transition to the sorbates of these complexes on PMMA and their fi lms, with RF elongation, their luminescence intensity is decreased, which may be due to steric hindrances for coordination of the Ln3+ ion with PMMA produced by the long fl uoroalkyl substituent. In connection with this, in a solid form, the luminescence intensity of Eu3+ and Tb3+ complexes with fluorinated β-diketones is the higher, the shorter the RF. However, with all the β-diketones studied, the luminescence intensity of the Eu3+ and Tb3+ complexes increases by 1-3 orders of magnitude when passing from solution to solid state. The measured lifetimes of the luminescence of Eu3+ and Tb3+ complexes with fluorinated β-diketones for sorbates and films are 1.5-2.6 times higher than the corresponding values for solutions. In addition, the investigated complex compounds showed a sufficiently high photostability to short-wave radiation under continuous irradiation, which can be used to expand the possibility of their practical application in solving scientific and scientific technical problems.

Keywords

• β-дикетонати лантанідів
• агрегатний стан
• люмінесценція