Open AccessРоль состояний переноса заряда "лиганд-металл" в процессах возбуждения люминесценции индолкарбоксилатов европия
Author(s) -
В.И. Царюк,
К.П. Журавлев
Publication year - 2022
Publication title -
optika i spektroskopiâ
Language(s) - English
Resource type - Journals
eISSN - 2782-6694
pISSN - 0030-4034
DOI - 10.21883/os.2022.01.51899.26-21
Subject(s) - europium , terbium , luminescence , excited state , chemistry , photochemistry , ternary operation , indole test , ligand (biochemistry) , materials science , stereochemistry , atomic physics , biochemistry , physics , receptor , optoelectronics , computer science , programming language
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 5D0 (Eu3+) and 5D4 (Tb3+) 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 5D0 state of the Eu3+ 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.