Excited Singlet State Radiative and Nonradiative Transition Probabilities for Acetone, Acetone-<i>d</i>6, and Hexafluoroacetone in the Gas Phase, in Solution, and in the Neat Liquid

Halpern, Arthur M.; Ware, William R.

doi:10.1063/1.1674964

Cited by 71 publications

(7 citation statements)

References 28 publications

(4 reference statements)

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“…The singlet lifetimes ( 1 τ) for acetone, 2-pentanone, 4-heptanone (all 1.95 ± 0.05 ns), and 2-hexanone (0.75 ± 0.04 ns) in 1,1,2-trichloro-1,2,2-trifluoroethane and for biacetyl in benzene (9.2 ± 0.4 ns) and cyclohexane (11.4 ± 0.3 ns) were determined by picosecond laser excitation and streak camera fluorescence detection. They are in excellent agreement with the literature values of 1.7 ns for acetone in cyclohexane, 1.8−2.0 ns for 2-pentanone in n -hexane, , 0.73 ns for 2-hexanone in n -hexane, and 10/11.5 ns for biacetyl in benzene/cyclohexane . The singlet lifetime for camphorquinone in benzene (15.9 ns) has been recently reported .…”

Section: Resultssupporting

confidence: 91%

Oxygen Quenching of Excited Aliphatic Ketones and Diketones

Nau

Scaiano

1996

J. Phys. Chem.

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The oxygen quenching rate constants of aliphatic ketones (acetone, 2-pentanone, 2-hexanone, 4-heptanone) and diketones (biacetyl and camphorquinone) have been determined for the singlet- and triplet-excited state by time-resolved fluorescence and triplet transient absorption spectroscopy, and the quantum yields for singlet oxygen formation were measured. It was observed that the quenching rate constants for the singlet state of aliphatic ketones are considerably smaller than for their triplet states. The efficiencies for singlet oxygen production of the aliphatic ketones were 0.2−0.3, while those of most diketones fall in the 0.4−0.6 range. The changes in the efficiencies for singlet oxygen production and of the oxygen-quenching rate constants for singlet- and triplet-excited n,π* states, ketones and azoalkanes are discussed in terms of variations in excited state energies and charge-transfer interactions with oxygen.

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Section: Resultssupporting

confidence: 91%

Oxygen Quenching of Excited Aliphatic Ketones and Diketones

Nau

Scaiano

1996

J. Phys. Chem.

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“…The fluorescence quantum yield has a slight wavelength dependence, therefore using Thurber's [14] formulae, a value of Φ f = 0.00096 can be estimated from our quantum yield measurements to the 296 nm excitation wavelength, where the lifetime determination was conducted. The derived k f = Φ f × 1 τ -1 = (3.7 ± 0.7) 10 5 s -1 shows good agreement with the recent determination by Koch et al [18] (k f = 3 10 5 s -1 ), and is definitely lower than that published before [17,[19][20] based on moderately higher fluorescence yields [20][21]. Utilising this new radiative rate constant together with the spectra shown in Fig.…”

Section: Photophysical Studiessupporting

confidence: 88%

Photochemical and photophysical study on the kinetics of the atmospheric photodissociation of acetone

Szilágyi

Kovács

et al. 2009

React Kinet Catal Lett

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The pressure dependence of the photodissociation quantum yield of acetone has been determined in different buffer gases at 308 nm. Results by Stern-Volmer analyses are in accordance with a suggested photolysis mechanism. Luminescence spectra, lifetimes and transition dipole moments have been determined. The energy transfer process by O 2 to give O 2 ( 1 ∆ g ) is of minor importance in the case of the singlet excited state of acetone, while it is the dominant deactivation process for the triplet state.

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“…The weak fluorescence of acetone (Φ f ca. 0.001) is readily observable with streak camera detection, and the effect of quenchers on the fluorescence lifetimes can be examined (Figure ). Each experiment provides as well the fluorescence spectrum (Figure ), which is important to rule out the observation of fluorescence from the quencher itself, impurities, or photoproducts.…”

Section: Resultsmentioning

confidence: 99%

Reactivity and Efficiency of Singlet- and Triplet-Excited States in Intermolecular Hydrogen Abstraction Reactions

1996

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The rate constants for quenching of the singlet- and triplet-excited state of acetone and a cyclic azoalkane by the hydrogen donors tributyltin hydride, 1,4-cyclohexadiene, and 2-propanol have been determined by time-resolved spectroscopy. It is concluded, in variance with previous studies, that singlet-excited states are significantly more reactive than triplet-excited states and that the reactivity difference between the two states of different spin multiplicity increases (i) with decreasing reactivity of the hydrogen donor and (ii) with increasing singlet−triplet energy gap of the excited state. This result is corroborated by semiempirical calculations. The relative efficiency for photoreduction by tributyltin hydride, which was determined by monitoring the formation of tributyltin radicals upon flash photolysis, was found to be four times lower for singlet-excited acetone than for the triplet state. The discrepancy between higher reactivity but lower efficiency in the intermolecular interaction of n,π*-excited singlet states with hydrogen donors is attributed to efficient radiationless deactivation, which has been predicted by correlation diagrams as a viable pathway for singlet-excited states.

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Excited Singlet State Radiative and Nonradiative Transition Probabilities for Acetone, Acetone-d6, and Hexafluoroacetone in the Gas Phase, in Solution, and in the Neat Liquid

Cited by 71 publications

References 28 publications

Oxygen Quenching of Excited Aliphatic Ketones and Diketones

Oxygen Quenching of Excited Aliphatic Ketones and Diketones

Photochemical and photophysical study on the kinetics of the atmospheric photodissociation of acetone

Reactivity and Efficiency of Singlet- and Triplet-Excited States in Intermolecular Hydrogen Abstraction Reactions

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