Non-radiative relaxation of the excited Ã 1B2u state of benzene

Callomon, J. H.; Parkin, J. E.; López-Delgado, R.

doi:10.1016/0009-2614(72)80059-9

Cited by 181 publications

(62 citation statements)

References 24 publications

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“…From this we may conclude that the symmetry of the excited state is of minor importance for the radiationless channel in the low as well as in the high excess energy range. Hence we may directly compare the results of this work with the former results from one-photon linewidth measurements [2]. From our results in Fig.…”

Section: Discussionsupporting

confidence: 59%

“…3 it is seen that the increase of radiationless decay around 3000 cm -1 excess energy is neither as steep as found in Ref. [2] nor leads to such faster rates as concluded from the linewidth measurements of [2,11]. The highest non-radiative rates are some 10 10 (sec -1 ) compared to rates of 10 12 (sec -1 ) from the hnewidth measurements.…”

Section: Discussionmentioning

confidence: 62%

“…This would explain the weak pressure dependence of this type of fluorescence since the collisional rate of about 10 9 (sec -1 ) at the highest pressure is still much smaller than the nonradiative rate, which is expected to be larger by at least two orders of magnitude from previous linewidth measurements [2].…”

Section: Discussionmentioning

confidence: 70%

“…To our knowledge it is questionable whether the linewidth measurement performed in Refs. [2,11] yields direct information about the kinetic Ti population relaxation time of vibronic levels. There may well exist fast phase erosion effects, even in the isolated molecule, that produce a broad linewidth for relatively long-lived levels.…”

Section: Discussionmentioning

confidence: 99%

“…increase in radiationless rates in the Si state of benzene when the vibrational excess energy exceeds about 3000 cm -1 [1]. High resolution absorption spectra in gas phase benzene revealed a diffuseness in the rotational contours of vibronic bands in the region of increased radiationless rates [2]. From the broadening in the spectrum a decay rate of more than 10 11 (sec -1 ) was concluded.…”

Section: Introductionmentioning

confidence: 99%

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Fluorescence from High Vibronically Excited Benzene: a "Channel Three" Problem

Wunsch

Neusser

Schlag

1981

Zeitschrift Für Naturforschung A

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Gas phase benzene is excited by two-photon absorption at various pressures between 4 and 80 torr. Fluorescence is observed even from states located at excess energies of 3000 cm -1 -7000 cm -1 , i.e. well above the onset of "channel three". The nonradiative decay rates as estimated from this fluorescence intensity continue the well known shortening of lifetime with excess energy in a monotone fashion and do not show a drastic cut-off as often concluded from previous linewidth measurements.

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Section: Discussionsupporting

confidence: 59%

Section: Discussionmentioning

confidence: 62%

Section: Discussionmentioning

confidence: 70%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Fluorescence from High Vibronically Excited Benzene: a "Channel Three" Problem

Wunsch

Neusser

Schlag

1981

Zeitschrift Für Naturforschung A

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Radiationless Auger‐Like Electronic Transitions in Biomolecules: Bio‐Auger Process

Bohr

Malik

2009

Digital Encyclopedia of Applied Physics

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Nonradiative relaxation process caused by the interaction between electrons in biomolecules following radiative absorption is discussed herein. The process is akin to Auger transitions in atoms to fill K, L, or M shell vacancies. Such Auger transitions in light elements are much faster than the radiative transition rate, and half‐lives could be in femtoseconds, as observed in many recent biomolecules being exposed to laser beams. After a brief introduction, the basic theory of Auger and electromagnetic transitions in atomic systems and the calculations based on that indicating dominance of the Auger process over the radiative one are presented in Section 2.2. The similarity and differentiation between the Auger process in atomic systems and similar ones in biomolecules, termed as Bio‐Auger processes , are presented in Section 2.3. The single orbital theory and the estimate of the timescale associated with Bio‐Auger processes are noted in Section 2.4, followed by a section on charge or electronic transfer associated with the Bio‐Auger process. In the last section, experimental evidence of the occurrence of the Bio‐Auger process after biomolecules are exposed to ultraviolet (UV) radiation is presented. In particular, calculations indicating the occurrence of electronic excited states in the energy range of UV radiation are noted. It is pointed out that (i) nonradiative transitions of Bio‐Auger type might be preventing cancer in biotissues exposed to the UV part of solar radiation; (ii) dark structures reported in exposing biomolecules to laser beam are electronic charge transfer; (iii) Bio‐Auger processes may lead to charge transfer of electrons from peridinin to chlorophyll‐ a in peridinin‐chlorophyll‐a protein (PCP) complex; and (iv) Bio‐Auger processes lead to de‐dimerization of thymine duplex formed in UV activated thymine bases in DNA as it comes in contact with optically activated cofactor riboflavin.

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