Competition between Intraligand Triplet Excited State and LMCT on the Thermal Quenching in β-Diketonate Complexes of Europium(III)

Villata, Laura S.; Wolcan, Ezequiel; Feliz, Miguel; Capparelli, Alberto L.

doi:10.1021/jp983714t

Cited by 53 publications

(38 citation statements)

References 26 publications

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“…In this case a temperature influence on the luminescence lifetime and intensity has been observed [8][9][10][11]. A temperature quenching has been attributed to the depopulation of the emitting 5 D 0 excited state via the upper 5 D 1 excited state [8,9]. On the other hand, many europium macrocyclic complexes showed intramolecular quenching due to the thermal population of a ligand to the metal charge-transfer (LMCT) excited state from the emitting state [9,10].…”

Section: Introductionmentioning

confidence: 97%

“…Eu 3+ ions have very intense PL bands in the 600-630 nm range (transition 5 D 0 -7 F 2 ), and PL excitation can be simply achieved through their ligand wide absorption bands (S 0 -S 1 ) with maximum around 290 nm [3,6,7]. In this case a temperature influence on the luminescence lifetime and intensity has been observed [8][9][10][11]. A temperature quenching has been attributed to the depopulation of the emitting 5 D 0 excited state via the upper 5 D 1 excited state [8,9].…”

Section: Introductionmentioning

confidence: 99%

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Optical properties of Eu(fod)3-doped polymers using supercritical carbon dioxide

Gerasimova

Zavorotny

Рыбалтовский

et al. 2009

Journal of Luminescence

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Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Optical properties of Eu(fod)3-doped polymers using supercritical carbon dioxide

Gerasimova

Zavorotny

Рыбалтовский

et al. 2009

Journal of Luminescence

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“…Secondly, due to pumping of the photoluminescence of the Eu 3+ ions through the organic component of the molecule, the photoluminescence intensity becomes temperature dependent. In this case, during quenching of the photoluminescence, various energy transport mechanisms may occur that are connected with population of the triplet level T 1 of the fod ligand [5][6][7] and also the levels of the f-f transitions of the Eu 3+ ions [8]. A contribution to the first mechanism may come from deformation of the Eu(fod) 3 molecules occurring with an increase in temperature [7], the degree of which in turn should depend on the "stiffness" of the matrix.…”

mentioning

confidence: 99%

“…In organometallics such as Eu(fod) 3 , thermal quenching may be due to two major energy transfer mechanisms. The first mechanism is depletion of the 5 D 0 level of the Eu 3+ ions as a result of either thermal population of the 5 D 1 level [8] or enhancement of deactivation processes, such as involving the OH oscillators [4,10]. The second mechanism is thermal deactivation of the triplet level of the organic component of the Eu(fod) 3 complex [5][6][7], since excitation of photoluminescence occurs specifically through the triplet level of the ligand.…”

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confidence: 99%

Thermal quenching of photoluminescence of Eu3+ ions in an Eu(fod)3 complex

et al. 2006

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Introduction.Currently transparent polymer materials are being increasingly widely used in optoelectronics. They are used as the basis for designing new types of integrated optics devices such as optical amplifiers, frequency selectors, three-dimensional memory devices, etc. Furthermore, study of the physical and chemical properties of polymers is of significant interest since those properties can change considerably when specific molecular compounds are added.Adding organometallic compounds to the internal free volume of samples using supercritical media, in particular supercritical carbon dioxide (supercritical CO 2 ), in order to modify their optical properties is a very advanced doping method [1,2]. A still unresolved question is how the matrix of the studied materials affects the spectral properties of the organometallics added to them.Such a property of Eu(fod) 3 molecules as the temperature dependence of the photoluminescence intensity in the range 20 o C-100 o C allows us to use doped polymers as highly sensitive temperature sensors which can be utilized, for example, in medicine. Moderate (up to 70 o C-80 o C) local heating of biological tissues by laser radiation is currently being used to correct the shape of the nasal septum, to regenerate intervertebral discs, and to treat tumors by hyperthermia. The required therapeutic effect is usually achieved when changes in the physical and chemical properties (especially mechanical, optical, and thermal properties) occur within the heated tissue interior as determined by the experimental conditions. Controlling the experimental conditions significantly reduces the likelihood of complications after laser procedures, and so monitoring such conditions has become important in both a scientific and practical sense. Designing such a sensor based on the effect of the temperature dependence of photoluminescence provides a noninvasive, rapid, highly sensitive, and optimal method for observing the conditions during laser heating of biological tissues.The aim of this work was to search for optical materials which can be used in designing a temperature sensor, and to study the effect of temperature on the photoluminescent properties of Eu(fod) 3 . In this project, we were guided by the following considerations. First of all, we need to choose a molecular compound that is photostable in the temperature range 20 o C-100 o C and has a sufficiently intense photoluminescence band in the visible region. Secondly, such a compound should be efficiently introduced into the matrices used with the help of supercritical CO 2 . At this time we have studied the process of quenching of the photoluminescence of Eu 3+ ions in several polymer materials such as polymethylmethacrylate (PMMA), polydimethylsiloxane (PDMS), and polypropylene (PP) doped with Eu(fod) 3 . For comparison, we also used the original polycrystalline Eu(fod) 3 powder in the experiments. The doping

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“…This process is reflected in the decrease in the photoluminescence intensity for the Eu 3+ ions. In this region of the absorption spectrum of the Eu(fod) 3 complex, we cannot rule out the possibility of finding a ligand-metal charge transfer band [22]. As we see from Fig.…”

Section: Introductionmentioning

confidence: 79%

Photosensitivity and thermosensitivity of polymers doped with Eu(fod)3 molecules

et al. 2009

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We have studied the photoluminescence (PL) spectra of Eu 3+ ions and the decay kinetics for the photoluminescence intensity on exposure to temperature and UV radiation in polypropylene and oligo(urethane methacrylate) (OUM) doped with Eu(fod) 3 molecules (fod = 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octadione) by soaking in a supercritical CO 2 solution. We have established that the decay kinetics for the photoluminescence intensity on exposure to UV radiation depends on the temperature of the sample and the concentration of the dopant in it. Based on studies of the spectral characteristics of doped OUM samples, we suggest that this material can be used as a two-color luminescent temperature sensor.

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Competition between Intraligand Triplet Excited State and LMCT on the Thermal Quenching in β-Diketonate Complexes of Europium(III)

Cited by 53 publications

References 26 publications

Optical properties of Eu(fod)3-doped polymers using supercritical carbon dioxide

Optical properties of Eu(fod)3-doped polymers using supercritical carbon dioxide

Thermal quenching of photoluminescence of Eu3+ ions in an Eu(fod)3 complex

Photosensitivity and thermosensitivity of polymers doped with Eu(fod)3 molecules

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