Comment on trivalent europium lifetimes in the presence of intramolecular energy transfer processes

Abstract

Este trabalho enfatiza a importância de se distinguir conceitualmente tempos-de-vida na ausência (tempos-de-vida naturais) e na presença de processos de transferência de energia intramolecular em compostos de coordenação com lantanídeos. O foco do artigo trata de compostos de európio trivalente com ligantes mistos, e uma análise de caso é feita sobre resultados apresentados recentemente na literature.This work emphasizes the importance of conceptually distinguishing between lifetimes in the absence (natural lifetimes) and in the presence of intramolecular energy transfer processes in lanthanide coordination compounds. It is focused on trivalent europium compounds with mixed ligands, and a case study is made on results recently reported in the literature.

Evidence of the participation of electronic excited states in the mechanism of positronium formation in substitutional Tb1−xEux(dpm)3 solid solutions studied by optical and positron annihilation spectroscopies

“…7. As well demonstrated by Carlos et al, 35 each one of these lifetimes is composed of a sum of reaction rate constants. In principle, both lifetimes can be quenched by the Eu complex in the solid solution.…”

Evidence of the Participation of Electronic Excited States in the Mechanism of Positronium Formation in Substitutional Tb_1-<i>x</i>Eu_<i>x</i>(dpm)₃ Solid Solutions Studied by Optical and Positron Annihilation Spectroscopies

“…The density of probability of {L*Tb e + *} formation also depends on the ligand and Eu(III) ion excited state lifetimes. Contrary to what was implicitly stated by Carlos et al, 35 the use of the steady state hypothesis does not lead to a misleading interpretation of the experimentally measured lifetime or of their components, once the steady state hypothesis does not determine these lifetimes, but only an approximated estimation of the ''concentrations'' of the decaying species. In this work, the steady state hypothesis is applied to the formation density probabilities of the different intermediary states of the kinetic mechanism.…”

“…, nearly the lowest experimental value for the triplet excite state to Eu 3+ ı´on energy transfer rate constant in various Eu(III) b-diketonates, 26,35 and finally k Qlum = k 8Tb + k 9Tb was fixed to its experimental values obtained as shown in Fig. 5.…”

Novel Photofunctional Multicomponent Rare Earth (Eu3+, Tb3+, Sm3+ and Dy3+) Hybrids with Double Cross‐linking Siloxane Covalently Bonding SiO2/ZnS Nanocomposite

“…The two main excitation peaks, 253 (252) nm and 329 (350) nm for Bipy-Dy-TESPIC-MPTMS-SiO 2 ⁄ ZnS and Phen-Dy-TESPIC-MPTMS-SiO 2 ⁄ ZnS can be assigned to the excitation of the p fi p* transition of liangds (Bipy or Phen) and double cross-linking siloxane (TESPIC-MPTMS) derived SiO 2 ⁄ ZnS (Si-O) network. Those f-f transitions within Dy 3+ 4f 9 configuration have also been observed, implying that there exists also an energy transfer from ligand to Dy 3+ in the samples (26). In the emission spectrum, the characteristic transition lines from the lowest excited 4 F 9 ⁄ 2 level of Dy 3+ to 6 H 15 ⁄ 2 (481 nm) and 6 H 13 ⁄ 2 (572 nm) are observed, dominated by the Dy 3+ 4 F 9 ⁄ 2 fi 6 H 13 ⁄ 2 hypersensitive transition (DJ = 2), which are strongly influenced by the outside surroundings and can be served as a very efficient and sensitive structural probe.…”

“…The sol‐gel method that is based on hydrolysis/condensation reactions is one kind of mature and economic application technology for preparing inorganic–organic luminescent hybrid materials. This method has unique advantages in synthesizing rare earth organic–inorganic hybrid materials such as low temperature, convenience, versatility and so on (9,10). Meanwhile, by altering the sol‐gel processing conditions, researchers may also control the microstructure, the external shape or the degree of combination between the inorganic and organic phases.…”