Temperature dependent high-resolution infrared photoabsorption cross-sections of trifluoromethyl sulphur pentafluoride

Kendall, Paul A.; Mason, Nigel J.; Buchanan, G. A.; Marston, George; Tegeder, Petra; Dawes, Anita; Eden, S.; Limão-Vieira, P.; Newnham, David

doi:10.1016/s0301-0104(02)00985-0

Cited by 22 publications

(41 citation statements)

References 13 publications

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“…These measurements have been made at much higher resolution in the last three years, and all the important IR-active vibrations in the atmospheric window region of ca. 700-1500 cm -1 have been determined [12][13][14]. Of particular note is the determination by two groups of the integrated absorption coefficient over this range as a function of temperature between 200 and 300 K [13,14], both studies demonstrating that it showed little variation with temperature.…”

Section: Structure Spectroscopy and Thermochemistry Of Sf 5 Cfmentioning

confidence: 98%

Chapter 3: Trifluoromethyl Sulphur Pentafluoride, SF5CF3: Atmospheric Chemistry and Its Environmental Importance via the Greenhouse Effect

Tuckett

2006

Fluorine and the Environment - Atmospheric Chemistry, Emissions, &Amp; Lithosphere

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Advances in Fluorine Science (2006) 1, chapter 3 (pp. 89-129) (Elsevier, ISBN 0-444-52811-3) Fluorine and the Environment : atmospheric chemistry, emissions and lithosphere DOI: 10.1016/S1872-0358(06) This is the author's version of a work that was accepted for publication in Advances in Fluorine Science.Changes resulting from the publishing process, such as editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in the reference given above. The DOI number of the final paper is also given above. highest per molecule radiative forcing of any greenhouse pollutant, and the value of its global warming potential is only exceeded by that of SF 6 . Using tunable vacuum-UV radiation from a synchrotron and coincidence spectroscopy, the strength of the central S−C bond in SF 5 CF 3 is determined to be 3.86 ± 0.45 eV or 372 ± 43 kJ mol -1 , and this molecule is very unlikely to be removed from the earth's atmosphere by UV photolysis in the stratosphere. Complementary laboratory-based experiments have shown that the main sink route of this greenhouse gas is low-energy electron attachment in the mesosphere, with Lyman-α photodissociation at 121.6 nm being only a minor channel. By comparison with data for SF 6 , the lifetime of SF 5 CF 3 in the earth's atmosphere is estimated to be ca. 1000 years. The principal reason for the current low level of concern about the impact of SF 5 CF 3 on our environment is that the concentration levels are still very low, at the sub parts per trilllion level. The high growth rate of ca. 6% per annum, however, should cause concern for policymakers.

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Section: Structure Spectroscopy and Thermochemistry Of Sf 5 Cfmentioning

confidence: 98%

Chapter 3: Trifluoromethyl Sulphur Pentafluoride, SF5CF3: Atmospheric Chemistry and Its Environmental Importance via the Greenhouse Effect

Tuckett

2006

Fluorine and the Environment - Atmospheric Chemistry, Emissions, &Amp; Lithosphere

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“…The latter two studies -following pioneering work on the total attachment cross-section for this molecule by Chen et al [19] -agreed in the observation that the dominant anion at low energies is SF 5 − while the respective findings for other anions were contradictory. Sailer et al [17] reported a band for CF 3 − formation with a peak cross-section of 0.35 × 10 −20 m 2 at 1.2 eV and a band for F − production peaking at about 0.9 eV (cross-section 0.08 × 10 −20 m 2 ) (in addition a weaker maximum at near-zero energies was seen in the F − yield).…”

Section: Introductionmentioning

confidence: 75%

“…This is significant because both SF 6 and SF 5 CF 3 are powerful greenhouse gases. The global warming potential (GWP) of SF 5 CF 3 is currently estimated at 18,500 times that of CO 2 [5,6], greater than almost any other molecule. The stratospheric profile that was measured by Sturges et al suggests this compound is long-lived in the atmosphere.…”

Section: Introductionmentioning

confidence: 99%

“…Previous reports on the electron attachment rate to SF 5 CF 3 place an upper limit of approximately 1000 years on the compound's atmospheric lifetime [7][8][9][10]. In addition to its atmospheric relevance, electron attachment studies to SF 5 CF 3 are of interest because of the comparisons we can make with SF 6 , a molecule used in many technological applications [11,12], and with the similar molecule SF 5 Cl for which we recently reported a comprehensive set of partial cross-sections for anion formation [13].…”

Section: Introductionmentioning

confidence: 99%

“…At energies below 1 eV, the SF 5 − anion is the dominant product, and we measure its DEA cross-section by two versions of the laser photoelectron attachment (LPA) method (LPA and extended laser photoelectron attachment (EXLPA), see Section 2.1) over the range 0.001-1.66 eV with energy widths of 2 meV (LPA) and about 25 meV (EXLPA). The LPA data are put on an absolute cross-section scale with reference to the well-known thermal (T = 300 K) DEA rate coefficient.…”

Section: Introductionmentioning

confidence: 99%

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Highly resolved absolute cross-sections for dissociative electron attachment to SF5CF3

Graupner¹,

Graham²,

Field³

et al. 2008

International Journal of Mass Spectrometry

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a b s t r a c tUsing two complementary experimental methods, we have measured partial (mass-resolved) crosssections for dissociative electron attachment to the molecule trifluoromethyl sulfurpentafluoride (SF 5 CF 3 ) at the gas temperature T G = 300 K over a broad range of electron energies (E = 0.001-12 eV). The absolute scale for these cross-sections was obtained with reference to the thermal (T = 300 K) rate coefficient for anion formation (8.0(3) × 10 −8 cm 3 s −1 ). Below 1 eV, SF 5 − is the dominant product anion and formed through the lowest anion state which cuts the neutral SF 5 CF 3 potential close to the S-C equilibrium distance. The highly resolved laser photoelectron attachment data exhibit a downward Wigner cusp at 86 meV, indicating that the 4 (a 1 ) vibrational mode is important for the primary attachment dynamics. Both SF 5 − and F − anions are formed with similar yields through the first excited resonance located near 3.6 eV. Towards higher energies, the anions CF 3 − , SF 4 − , and SF 3 − are also produced. Summation of the partial cross-sections yields a total absolute cross-section for anion formation over the energy range 0.001-12 eV. This is used to calculate the dependence of the rate coefficient for dissociative electron attachment over a broad range of electron temperatures for the fixed gas temperature T G = 300 K; good agreement is found between the calculated values and those obtained in a drift tube experiment. In addition to the experimental work, semiempirical R-matrix calculations have been carried out for the energy dependence of the cross-section for SF 5 − formation. The experimental findings are semi-quantitatively recovered.

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Vacuum Ultraviolet Negative Photoion Spectroscopy of SF6, CF4 and SF5CF3

Simpson

2011

Two Studies in Gas-Phase Ion Spectroscopy

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Temperature dependent high-resolution infrared photoabsorption cross-sections of trifluoromethyl sulphur pentafluoride

Cited by 22 publications

References 13 publications

Chapter 3: Trifluoromethyl Sulphur Pentafluoride, SF5CF3: Atmospheric Chemistry and Its Environmental Importance via the Greenhouse Effect

Chapter 3: Trifluoromethyl Sulphur Pentafluoride, SF5CF3: Atmospheric Chemistry and Its Environmental Importance via the Greenhouse Effect

Highly resolved absolute cross-sections for dissociative electron attachment to SF5CF3

Vacuum Ultraviolet Negative Photoion Spectroscopy of SF6, CF4 and SF5CF3

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