Proton Transfer Reactions in the Excited Electronic States of Aromatic Molecules

Martynov, I. Yu.; Demyashkevich, A. B.; Uzhinov, B. M.; Kuz’min, M. G.

doi:10.1070/rc1977v046n01abeh002116

Cited by 118 publications

(92 citation statements)

References 7 publications

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“…[4][5][6][7][8][9][10][11][12][13][14] In recent years most authors have tended to assume phototautomer forms to be quinoid-like. Our results confirm this statement.…”

Section: Compoundmentioning

confidence: 99%

“…Several pieces of evidence in favor of the irreversibility of the ESIPT process (the basis of the following scheme) could be found in numerous reviews. [4][5][6][7][8][9][10][11][12][13][14] In this scheme NF refers to the normal form and PT to the phototautomer form, W is the rate of electronic excitation, k f (with the appropriate indices) are radiative rate constants for the normal form and the phototautomer, k d correspond to the radiationless deactivation rate constants and k ESIPT is the rate constant of the ESIPT reaction. For conditions of a photostationary state, one can deduce the following equations for fluorescence quantum yields of normal (9 NF ) and phototautomer (9 PT ) forms, which can be determined experimentally:…”

Section: Compoundmentioning

confidence: 99%

“…3 The excited state intramolecular proton transfer (ESIPT) reaction plays an important role within the limited quantity of known primary photochemical and photophysical processes which result in fluorescence with abnormally high Stokes shifts. [4][5][6][7][8][9][10][11][12][13][14] The product of the ESIPT reaction, excited phototautomer form, emits light in a longer wavelength region than the emission of the initial 'normal' form. The Stokes shift values typical of phototautomer forms vary in the range 6000-12 000 cm À1 for different ESIPT compounds.…”

Section: Introductionmentioning

confidence: 99%

“…4,6,8,[10][11][12][13][14][15] In spite of the large number of publications on ESIPT (several hundred), there are only a few which deal with the influence of the structure of organic compounds on the rate constants of proton transfer and radiationless deactivation connected with the discussed reaction (see, e.g., Refs. .…”

Section: Introductionmentioning

confidence: 99%

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Excited state intramolecular proton transfer reaction and luminescent properties of theortho-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole

Дорошенко

Posokhov

Verezubova

et al. 2000

J. Phys. Org. Chem.

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Luminescent properties of several ortho‐hydroxy derivatives of 2,5‐diphenyl‐1,3,4‐oxadiazole were studied in solvents of different polarity and protolytic ability and compared with the analogous derivatives of 1,3‐oxazole, studied by us earlier. Evaluations of rate constants for the excited state intramolecular proton transfer (ESIPT) reaction and radiationless degradation of the energy of electronic excitation in the ESIPT reaction product, phototautomer form, were made on the basis of fluorescence quantum yields and fluorescence kinetic measurements. The proton phototransfer reaction is the most efficient primary photoprocess in the examined series of compounds. With rate constants of 1011–1012 s−1 it exceeds the rates of other primary photophysical processes in these molecules by up to 2–3 orders of magnitude. A connection between the rate of the ESIPT reaction and the electron density redistribution on electronic excitation was revealed for the molecules under study. The electron donor substituents in 5‐phenyl decrease the proton phototransfer rate constant up to complete inhibition of the ESIPT process in the case of the dimethylamino derivative of the oxazole series, whereas the electron acceptor substituents must accelerate this reaction. The determining role of the excited state increase of the proton donor group acidity was assumed on the basis of experimental data and quantum chemical calculations. The temperature investigations showed that the ESIPT reaction in the series of ortho‐hydroxy derivatives of 2,5‐diphenyloxazole and 2,5‐diphenyl‐1,3,4‐oxadiazole has a very low activation barrier. However, the radiationless processes in the phototautomer form are characterized by the presence of a certain barrier in both examined series. A dependence of the radiationless dissipation rate in the phototautomer form on the excited state redistribution of the electron density in it was also found. The more efficient is the charge transfer from the ortho‐phenolate fragment to the protonated heterocycle and the rest of the molecule, the more efficient are the radiationless losses. It was revealed that structural changes, which prevent the mentioned movement of electron density, result in an increase in the fluorescence efficiency of the phototautomer form and, hence, also to an increase in the total fluorescence quantum yield of the ESIPT molecule. Copyright © 2000 John Wiley & Sons, Ltd.

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“…[4][5][6][7][8][9][10][11][12][13][14] In recent years most authors have tended to assume phototautomer forms to be quinoid-like. Our results confirm this statement.…”

Section: Compoundmentioning

confidence: 99%

Section: Compoundmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Excited state intramolecular proton transfer reaction and luminescent properties of theortho-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole

Дорошенко

Posokhov

Verezubova

et al. 2000

J. Phys. Org. Chem.

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show abstract

“…Photoacids, first investigated by Förster and Weller [2,[30][31][32], are a class of molecules that exhibit a strong change in acidity upon electronic excitation [33][34][35][36]. Examples of photoacid compounds are naphthols, pyrenols and aminopyrenes [34,37].…”

Section: Photoacids As Ultrafast Optical Triggers For Proton Transfermentioning

confidence: 99%

Bimolecular Proton Transfer in Solution

Nibbering

Pines

2006

Hydrogen‐Transfer Reactions

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UV‐Visible Spectra and Photoacidity of Phenols, Naphthols and Pyrenols

Pines¹

2003

PATAI'S Chemistry of Functional Groups

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Proton Transfer Reactions in the Excited Electronic States of Aromatic Molecules

Cited by 118 publications

References 7 publications

Excited state intramolecular proton transfer reaction and luminescent properties of theortho-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole

Excited state intramolecular proton transfer reaction and luminescent properties of theortho-hydroxy derivatives of 2,5-diphenyl-1,3,4-oxadiazole

Bimolecular Proton Transfer in Solution

UV‐Visible Spectra and Photoacidity of Phenols, Naphthols and Pyrenols

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