Paper by V L Ermolaev, E B Sveshnikova and E N Bodunov 'Inductive-resonant mechanism of nonradiative transitions in ions and molecules in condensed phase' [<i>Physics – Uspekhi</i>, March 1996, 39 (3) 261 – 282]

Ермолаев, В. Л.; Свешникова, Е. Б.; Bodunov, E. N.

doi:10.1070/pu1997v040n03abeh001592

Cited by 46 publications

(77 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the calculations, we ignored the probability of internal conversion k S 1 S 0 . This was suggested by the data on the good compliance with the Ermolaev-Sveshnikova rule ϕ F + ϕ T = 1 [10] for metallophthalocyanines [11,12], in the structure of which there are also four nitrogen bridges, but the energy interval S 1 -S 0 is much smaller than for H 2 TAP. (The data for nonmetallic phthalocyanine and its substituents [13][14][15] are less definite but nevertheless allow the conclusion that the role of the internal conversion is insignificant.)…”

mentioning

confidence: 84%

Influence of a Solvent on the Quantum Yield and Duration of the Fluorescence of Tetraazoporphin

et al. 2005

View full text Add to dashboard Cite

ev UDC 535.37In view of the discrepancies between the values available in the literature for the photophysical parameters of tetraazaporphin in solutions, we measured its quantum yield and duration of fluorescence in a number of solvents. It has been found that alcohols (isobutanol and isopropanol) quench the fluorescence appreciably. For a solution in toluene -a stable chemically inactive and low-polar solvent -the measured quantum yield of the fluorescence of tetraazaporphin is equal to 0.180 ± 0.015 and its duration is 3.4 ± 0.1 nsec.Keywords: tetraazaporphin, quantum yield of fluorescence, fluorescence duration.Introduction. The tetraazaporphin (H 2 TAP) molecule, or porphyrazine, is one of the fundamental structures in the porphin series, which is an intermediate between the biologically important class of porphyrins and classical dyes of the type of phthalocyanine, which are finding wide application in various fields of science and technology.In investigating the effect of hydrogenation of pyrrolic rings in porphyrazine macrocycles on the photophysical properties, in [1, 2] the quantum yield of fluorescence (ϕ F ) of H 2 TAP was measured as a basis for comparison with the data on dihydroderivatives. By comparing our results with the data of earlier investigations [3-6], we found that there were noticeable discrepancies between the values of ϕ F measured by various authors and also between the data on durations of fluorescence τ F . In [3,4], it was found that ϕ F = 0.12 and τ F = 3.7 nsec (see also the review [7]), in [5], ϕ F = 0.16 and τ F = 6.4 nsec; in [6], ϕ F = 0.12. Recently,in [8], the value ϕ F = 0.29 was obtained for H 2 TAP, whereas in [1, 2] ϕ F = 0.19 and τ F = 3.3 nsec.Since different solvents were used in the works cited, the idea arose that the quantity ϕ F of H 2 TAP can substantially depend on the nature of the solvent. The aim of the present work is to elucidate this influence and to arrange in an ordered fashion the data on the values of ϕ F and τ F for H 2 TAP.Experimental. Measurements of the quantum yield of fluorescence were performed by a relative method from the ratio between the areas of the fluorescence spectra of an object and a standard determined in terms of "quantum" intensities (I λ /hν) on an SDL-2 automated spectrofluorimeter (USSR) consisting of an MDR-12 light-transmission excitation monochromator and an MDR-23 registration monochromator. The excitation and registration axes were arranged at an angle of 90 o . A DKsSh-120 xenon lamp was used as the source of excitation. The light signal separated by the monochromator was registered with the aid of an FÉU-100 cooled photomultiplier (spectral range 200-800 nm) operating in the regime of photon counting. The spectral sensitivity of the recording monochromator-FÉU system was corrected with the aid of a TRSh 2850 standard ribbon tungsten lamp. The spectral width of the excitation monochromator slit did not exceed 4.8 nm in the entire spectral range studied, and that of the registration monochromator -2.6 nm in the 400-800-nm ...

show abstract

mentioning

confidence: 84%

Influence of a Solvent on the Quantum Yield and Duration of the Fluorescence of Tetraazoporphin

et al. 2005

View full text Add to dashboard Cite

show abstract

“…£ÇÓÑâÕÐÑÔÕß ÃÇÊÞÊÎÖÚÂÕÇÎßÐÑÅÑ ÒÇÓÇØÑAEÂ S 1 * * *b T 1 ì ËÐÕÇÓÍÑÏÃËÐÂÙËÑÐÐÑÌ ÍÑÐÄÇÓÔËË (ÔÑÍÓÂÜÇÐÐÑ ì ËÐÕÇÓÍÑÐÄÇÓÔËË, Ä ÂÐÅÎÑâÊÞÚÐÑÌ ÎËÕÇÓÂ-ÕÖÓÇ ì intersystem crossing) ÑÍÂÊÞÄÂÇÕÔâ ÒÑàÕÑÏÖ ÐÂ ÐÇÔÍÑÎßÍÑ ÒÑÓâAEÍÑÄ ÏÇÐßÛÇ, ÚÇÏ ÄÇÓÑâÕÐÑÔÕß ÄÐÖÕÓÇÐ-ÐÇÌ ÍÑÐÄÇÓÔËË S 2 * * *b S 1 , ÐÑ àÕÑÅÑ AEÑÔÕÂÕÑÚÐÑ, ÚÕÑÃÞ à××ÇÍÕËÄÐÑ ÍÑÐÍÖÓËÓÑÄÂÕß Ô ËÊÎÖÚÂÕÇÎßÐÞÏ ÒÇÓÇØÑAEÑÏ S 1 3 S 0 . ¦ÓÏÑÎÂÇÄÞÏ Ë ³ÄÇÛÐËÍÑÄÑÌ ÐÂ ÑÔÐÑÄÂÐËË ÃÑÅÂÕÑÅÑ àÍÔÒÇÓËÏÇÐÕÂÎßÐÑÅÑ ÏÂÕÇÓËÂÎÂ ÃÞÎÑ Ô×ÑÓÏÖ-ÎËÓÑÄÂÐÑ ÒÓÂÄËÎÑ j F j T 1 (ÅAEÇ j F ì ÍÄÂÐÕÑÄÞÌ ÄÞØÑAE ×ÎÖÑÓÇÔÙÇÐÙËË; j T ì ÍÄÂÐÕÑÄÞÌ ÄÞØÑAE ËÐÕÇÓÍÑÐ-ÄÇÓÔËË), ÍÑÕÑÓÑÇ ÑÊÐÂÚÂÇÕ, ÚÕÑ ËÐÕÇÓÍÑÐÄÇÓÔËâ âÄÎâÇÕÔâ ÅÎÂÄÐÞÏ ÍÂÐÂÎÑÏ ÃÇÊÞÊÎÖÚÂÕÇÎßÐÑÌ AEÇÊÂÍÕËÄÂÙËË ÖÓÑÄÐâ S 1 , Â ÄÐÖÕÓÇÐÐââ ÍÑÐÄÇÓÔËâ S 1 * * *b S 0 ÐÇÔÖÜÇÔÕ-ÄÇÐÐÂ [15]. ³ ÖÚÇÕÑÏ àÕÑÅÑ ÄÞÓÂÉÇÐËÇ AEÎâ ÍÄÂÐÕÑÄÑÅÑ ÄÞØÑAEÂ ×ÎÖÑÓÇÔÙÇÐÙËË…”

Section: £äçAeçðëçunclassified

Intramolecular heavy-atom effect in the photophysics of organic molecules

Соловьев¹,

Borisevich²

2005

Usp. Fiz. Nauk

View full text Add to dashboard Cite

“…2a), since a considerable effect on deactivation processes for the photoluminescence of Eu 3+ ions comes from the presence of OH oscillators and H 2 O molecules, which increases as the temperature increases [4,10]. Fig.…”

mentioning

confidence: 95%

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

et al. 2006

View full text Add to dashboard Cite

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

show abstract

Paper by V L Ermolaev, E B Sveshnikova and E N Bodunov 'Inductive-resonant mechanism of nonradiative transitions in ions and molecules in condensed phase' [Physics – Uspekhi, March 1996, 39 (3) 261 – 282]

Cited by 46 publications

References 0 publications

Influence of a Solvent on the Quantum Yield and Duration of the Fluorescence of Tetraazoporphin

Influence of a Solvent on the Quantum Yield and Duration of the Fluorescence of Tetraazoporphin

Intramolecular heavy-atom effect in the photophysics of organic molecules

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

Contact Info

Product

Resources

About