Enhanced luminescence of the europium(III)-terbium(III)-dibenzoylmethane-ammonia-acetone system and its application to the determination of europium

Abstract

The enhanced luminescence of the Eudibenzoylmethane(DBM) -NH3system in the presence ofTb3+ and the effect of solvents on that system in the absence of Tb3+ were studied. The optimum conditions for co-luminescence of the Eu -Tb -DBM -NH3 system were examined. The optimised procedure was applied to the determination of trace amounts of Eu. The detection limit is 4.0 x 10-11 M, which is about two orders of magnitude lower than that of the system in the absence of Tb. An intermolecular transfer of energy from the enhancing complex to the fluorescing complex is proposed.

Ligand-sensitized fluorescence of Eu3+ using naphthalene carboxylic acids as ligands

“…Similarly, no enhancement was observed when Tb 3+ was added to Eu 3+ -NA-TOPO/ Triton X-100. Fluorescence enhancement of Eu 3+ following the addition of Tb 3+ has previously been reported for complexes of Eu 3+ with dibenzoylmethane and ammonia [25]. In earlier studies, we had also observed that polycarboxylic acid ligands exhibited such co-fluorescence following the addition of lanthanides such as La 3+ , and we had suggested that such enhancement occurs due to the formation of polynuclear complexes.…”

“…This process is referred to as co-fluorescence and occurs following an energy transfer between the complexes of the different lanthanides, provided the acceptor and donor complexes are in close proximity. In some cases, the co-fluorescence is also believed to occur due to the formation of polynuclear complexes [23][24][25][26][27][28][29][30].…”

Factors Affecting Luminescence Intensity of Lanthanide Ions. Analytical Applications of Lanthanide Luminescence in Solution

“…The intramolecular energy transfer from the triplet state of the organic hgand to the lanthanide ion, depending on the stucture of the ligand and the position of its triplet level, markedly increase the fluorescence intensity [14,15]. The β-diketone chelates of Sm(III), Eu(III), Tb(III), and Dy(III) showing very strong ion fluorescence, attributed to the fact of the efficient intramolecular triplet-to--emitting level energy transfer, are the most extensively studied and used in analytical applications [16][17][18][19][20].…”

“…The β-diketone chelates of Sm(ΙΙΙ), Eu(III), Tb(III), and Dy(III) showing very strong ion fluorescence, attributed to the fact of the efficient intramolecular t r i p l e t -t o -e m i t t i n g l e v e l e n e r g y t r a n s f e r , a r e t h e m o s t e x t e n s i v e l y s t u d i e d a n d u s e d in analytical applications [16][17][18][19][20].…”

Syntheses and Co-Fluorescence of Complexes of Eu (III)/Gd (III) with Thienyltrifluoroacetonate, Terephthalic Acid and Phenanthroline

“…In the presence of these ions, the fluorescence enhancement of some rare earth complexes can be obtained. This process is referred to as co-fluorescence, which is extensively studied in the mononuclear complexes of Europiun (III) ions with β-diketones ligands, such as Eu(TTA) 3 Phen [12], Eu(Dbm) 3 Phen [13] and Eu(TTA) 3 TPPO 2 . As far as the mononuclear complex is concerned, the co-fluorescence can be found in a micellar environment [16] [17].…”