Role of LMCT States in Luminescence Excitation Processes in Europium Indolecarboxylates
The luminescence excitation energy transfer in europium and terbium indole-3-carboxylates, indole-3-acetates and indole-3-propionates as well as ternary indolecarboxylates containing 1,10-phenanthroline and 2,2'-bipyridine molecules have been studied. The luminescence excitation spectra, the li...
Saved in:
Published in | Optics and spectroscopy Vol. 131; no. 10; pp. 1103 - 1111 |
---|---|
Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Moscow
Pleiades Publishing
01.10.2023
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The luminescence excitation energy transfer in europium and terbium indole-3-carboxylates, indole-3-acetates and indole-3-propionates as well as ternary indolecarboxylates containing 1,10-phenanthroline and 2,2'-bipyridine molecules have been studied. The luminescence excitation spectra, the lifetimes of the
5
D
0
(Eu
3+
) and
5
D
4
(Tb
3+
) states, and the luminescence intensity are analyzed. The decisive role of ligand-metal charge transfer (LMCT) states in the quenching of the luminescence of europium aromatic carboxylates containing a π-excessive pyrrole or indole fragment is demonstrated. Most europium compounds are characterized by quenching due to the depopulation of the
5
D
0
state of the Eu
3+
ion through the low-energy LMCT state. But in some ternary compounds, the LMCT state being of higher energy participates in the nonradiative depopulation of the excited electronic states of the ligand. |
---|---|
ISSN: | 0030-400X 1562-6911 |
DOI: | 10.1134/S0030400X23100259 |