Decay processes of singlet excited phenol in solution

Köhler, Gabriele; Kittel, G.; Getoff, N.

doi:10.1016/0047-2670(82)80004-x

Cited by 51 publications

(13 citation statements)

References 21 publications

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“…At 25°c, these quantum yields are 0.78, 0.75 and 0.81 for 4o, 4m and 4p , respectively, the remainder of the reactivity of S 1 being accounted for by fluorescence. Support for this conclusion is given by the high value of φ isc = 0.64 (29) and 0.74 (30) reported previously for anisole.…”

Section: Discussionsupporting

confidence: 53%

Temperature Effects, Arrhenius Activation Parameters and Rate Constants for the Photochemical Reactivity of Cyano, Boronato, Trifluoromethyl and Methoxy Substituted Toluenes in the Excited Singlet State†

Gonzalez

Pincock

2006

Photochem Photobiol

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Total rate constants of decay (k(t)) as a function of temperature from -45 to +65 degrees C for the compounds 1 and 2 in AN and TFE and 3 and 4 in AN have been determined by fluorescence lifetime measurements. The data have been fit to an equation that assumes that the rate constants of fluorescence (k(f)) and intersystem crossing (k(isc)) are temperature independent, that k(ic) = 0 and that the rate constant of reaction (k(r)) is activated according to the Arrhenius expression. For compounds 1-3, values of k(f) and k(isc) were found to be independent of solvent for any given compound, but k(r) was consistently greater in TFE than AN. For the anisoles 4, the temperature effect was very small, indicating that k(r) did not compete with k(f) + k(isc) and suggesting that an activated intersystem crossing was the dominant temperature-dependent process. The k(r), A and E(a) values obtained for compounds 1-3 were rationalized in terms of their known photochemistry, phototransposition reactions in AN and photoadditions in TFE. The critical reactive intermediate in all cases is a bicycle[3.1.0]hexenyl biradical/zwitterion that is formed in an activated process from S1. This reactive intermediate returns to starting material faster than it rearranges, and therefore an activated internal conversion is a major pathway for deactivation of S1.

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Section: Discussionsupporting

confidence: 53%

Temperature Effects, Arrhenius Activation Parameters and Rate Constants for the Photochemical Reactivity of Cyano, Boronato, Trifluoromethyl and Methoxy Substituted Toluenes in the Excited Singlet State†

Gonzalez

Pincock

2006

Photochem Photobiol

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“…This is presumably the dominant photochemical channel. H release of phenol after UV excitation in the energy range of the S 2 (pp*) state has been observed, however, both in the condensed phase 39 and in the gas phase. 40 More detailed gas-phase investigations are necessary to establish that the H release is a direct process on the 1 ps* surface, rather than a statistical dissociation process on the ground-state surface.…”

Section: -22mentioning

confidence: 98%

Excited-state hydrogen detachment and hydrogen transfer driven by repulsive 1πσ* states: A new paradigm for nonradiative decay in aromatic biomolecules

Sobolewski

Domcke

Dedonder‐Lardeux

et al. 2002

Phys. Chem. Chem. Phys.

925

1,207

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“…Photoexcited 4,4 0 -thiodiphenol molecules can ionize into the corresponding phenoxyl radicals and hydrated electrons. [79][80][81][82][83][84][85][86][87] The lifetime of these hydrated electrons is mainly limited by reaction m (Table 6) which might explain the lack of EPR signals of the free electron. 88 Table 6 further lists the reaction rate of phenol with hydrated electrons as the value for 4,4 0 -thiodiphenol could not be found in the literature, but the latter is expected to be in the same order of magnitude.…”

Section: 2-bis(4-hydroxyphenyl)hexafluoropropane (A)mentioning

confidence: 99%

EPR spectroscopic investigation of radical-induced degradation of partially fluorinated aromatic model compounds for fuel cell membranes

Schönberger

Kerres

Dilger³

et al. 2009

Phys. Chem. Chem. Phys.

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EPR spectroscopic investigations of reactions between monomeric model compounds representing typical structural moieties of poly(aryl) ionomers and photochemically generated hydroxyl radicals are reported. Deoxygenated solutions of the model compounds (in a water/methanol mixture) containing hydrogen peroxide at defined pH values were exposed to UV light in the flow cell within the cavity of an EPR spectrometer. Spectra were analyzed by computer simulation and the formed radicals were assigned by comparing their g-factors and hyperfine coupling constants (hfccs) with those from the literature and from density functional theory (DFT) calculations. The relevance for polymer electrolyte membrane fuel cells (PEMFCs) and alkaline-anion exchange membrane fuel cells (AAEMFCs) is discussed.

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Decay processes of singlet excited phenol in solution

Cited by 51 publications

References 21 publications

Temperature Effects, Arrhenius Activation Parameters and Rate Constants for the Photochemical Reactivity of Cyano, Boronato, Trifluoromethyl and Methoxy Substituted Toluenes in the Excited Singlet State†

Temperature Effects, Arrhenius Activation Parameters and Rate Constants for the Photochemical Reactivity of Cyano, Boronato, Trifluoromethyl and Methoxy Substituted Toluenes in the Excited Singlet State†

Excited-state hydrogen detachment and hydrogen transfer driven by repulsive 1πσ* states: A new paradigm for nonradiative decay in aromatic biomolecules

EPR spectroscopic investigation of radical-induced degradation of partially fluorinated aromatic model compounds for fuel cell membranes

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