Premium
Dependence of the Lifetime upon the Excitation Energy and Intramolecular Energy Transfer Rates: The 5 D 0 Eu III Emission Case
Author(s) -
Ferreira Rute A. S.,
Nolasco Mariela,
Roma Ana C.,
Longo Ricardo L.,
Malta Oscar L.,
Carlos Luis D.
Publication year - 2012
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201201736
Subject(s) - intramolecular force , excitation , ionic bonding , lanthanide , ion , förster resonance energy transfer , chemical physics , chemistry , atomic physics , materials science , fluorescence , physics , stereochemistry , optics , organic chemistry , quantum mechanics
In many Eu III ‐based materials, the presence of an intermediate energy level, such as ligand‐to‐metal charge transfer (LMCT) states or defects, that mediates the energy transfer mechanisms can strongly affect the lifetime of the 5 D 0 state, mainly at near‐resonance (large transfer rates). We present results for the dependence of the 5 D 0 lifetime on the excitation wavelength for a wide class of Eu III ‐based compounds: ionic salts, polyoxometalates (POMs), core/shell inorganic nanoparticles (NPs) and nanotubes, coordination polymers, β‐diketonate complexes, organic–inorganic hybrids, macro‐mesocellular foams, functionalized mesoporous silica, and layered double hydroxides (LDHs). This yet unexplained behavior is successfully modelled by a coupled set of rate equations with seven states, in which the wavelength dependence is simulated by varying the intramolecular energy transfer rates. In addition, the simulations of the rate equations for four‐ and three‐level systems show a strong dependence of the emission lifetime upon the excitation wavelength if near‐resonant non‐radiative energy transfer processes are present, indicating that the proposed scheme can be generalized to other trivalent lanthanide ions, as observed for Tb III /Ce III . Finally, the proper use of lifetime definition in the presence of energy transfer is emphasized.