Electron impact ionisation and UV absorption study of α- and β-pinene

Kubala, D.; Drage, E. A.; Al-Faydhi, Anwar Mustafa Ezzat; Kočišek, Jaroslav; Papp, P.; Matejčı́k, Viktor; Mach, Pavel; Urban, Ján; Limão-Vieira, P.; Hoffmann, Søren Vrønning; Matejčík, Štefan; Mason, Nigel J.

doi:10.1016/j.ijms.2008.07.035

Cited by 21 publications

(35 citation statements)

References 26 publications

(29 reference statements)

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“…It is significantly larger than σ α-pinene and similar to values reported for other terpenes, e.g. σ (in 10 −17 cm 2 molecule −1 ) = 2.3 for β-pinene (Kubala et al, 2009) and 4.6 for limonene (Smialek et al, 2012). Assessment of potential systematic errors results in an overall uncertainty of ≈ 5 %, i.e.…”

Section: Absorption Cross Sections (σ ) For Isoprenesupporting

confidence: 74%

“…σ α-pinene = (1.54 ± 0.08) × 10 −17 cm 2 molecule −1 at 184.95 nm. This value is significantly larger than that listed in the UV spectrum (116-250 nm) of Kubala et al (2009), who report a value of 1.28× 10 −17 cm 2 molecule −1 . The reasons for this ≈ 15 % discrepancy are unclear.…”

Section: Absorption Cross Sections (σ ) For Isoprenecontrasting

confidence: 59%

“…(2) to yield B parameters with a high degree of precision (±5 % or less). As with the determinations of k 1 detailed above, systematic errors due to secondary chemistry were considered unlikely, since monoterpenes absorb only weakly at the photolysis wavelength (the 248 nm cross section is <1 × 10 −20 cm 2 molecule −1 (Kubala et al, 2009), resulting in photolysis of <1 × 10 11 molecule cm −3 ) of α-pinene. Furthermore, use of small OH concentrations and hence low conversion of α-pinene ensured that perturbations to the LIF profiles by reaction of OH with itself or with the products of Weighted linear fits yield (in units of 10 −11 cm 3 molecule −1 s −1 ): k 2 (296 K) = (5.3 ± 0.15) from the red squares and k 3 (296 K) = (8.1 ± 0.1) (blue circles).…”

Section: Comparison Of K 1 With Literature Valuesmentioning

confidence: 99%

“…Currently the database for 184.95 nm cross sections is sparse, consisting of only the results from this work and one other reported value for σ α-pinene from Kubala et al (2009). Any subsequent improvements in the database for 184.95 nm absorption cross sections for monoterpenes should be used to obtain up to date rate coefficients k 2 (T ) and k 3 (T ).…”

Section: Comparison Of K 1 With Literature Valuesmentioning

confidence: 99%

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Temperature-dependent rate coefficients for the reactions of the hydroxyl radical with the atmospheric biogenics isoprene, alpha-pinene and delta-3-carene

et al. 2017

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Abstract. Pulsed laser methods for OH generation and detection were used to study atmospheric degradation reactions for three important biogenic gases: OH + isoprene (Reaction R1), OH +α-pinene (Reaction R2) and OH + -3-carene (Reaction R3). Gas-phase rate coefficients were characterized by non-Arrhenius kinetics for all three reactions. For (R1), k 1 (241-356 K) = (1.93 ± 0.08) × 10 −11 exp{(466 ± 12)/T } cm 3 molecule −1 s −1 was determined, with a room temperature value of k 1 (297 K) = (9.3± 0.4) × 10 −11 cm 3 molecule −1 s −1 , independent of bath-gas pressure (5-200 Torr) and composition (M = N 2 or air). Accuracy and precision were enhanced by online optical monitoring of isoprene, with absolute concentrations obtained via an absorption cross section, σ isoprene = (1.28 ± 0.06) × 10 −17 cm 2 molecule −1 at λ = 184.95 nm, determined in this work. These results indicate that significant discrepancies between previous absolute and relative-rate determinations of k 1 result in part from σ values used to derive the isoprene concentration in high-precision absolute determinations.Similar methods were used to determine rate coefficients (in 10 −11 cm 3 molecule −1 s −1 ) for (R2)-(R3): k 2 (238-357 K) = (1.83 ± 0.04) × exp{(330 ± 6)/T } and k 3 (235-357 K) = (2.48±0.14)×exp{(357±17)/T }. This is the first temperature-dependent dataset for (R3) and enables the calculation of reliable atmospheric lifetimes with respect to OH removal for e.g. boreal forest springtime conditions. Room temperature values of k 2 (296 K) = (5.4 ± 0.2) × 10 −11 cm 3 molecule −1 s −1 and k 3 (297 K) = (8.1 ± 0.3) × 10 −11 cm 3 molecule −1 s −1 were independent of bathgas pressure (7-200 Torr, N 2 or air) and in good agreement with previously reported values. In the course of this work, 184.95 nm absorption cross sections were determined: σ = (1.54 ± 0.08) × 10 −17 cm 2 molecule −1 for α-pinene and (2.40 ± 0.12) × 10 −17 cm 2 molecule −1 for -3-carene.

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Section: Absorption Cross Sections (σ ) For Isoprenesupporting

confidence: 74%

Section: Absorption Cross Sections (σ ) For Isoprenecontrasting

confidence: 59%

Section: Comparison Of K 1 With Literature Valuesmentioning

confidence: 99%

Section: Comparison Of K 1 With Literature Valuesmentioning

confidence: 99%

See 2 more Smart Citations

Temperature-dependent rate coefficients for the reactions of the hydroxyl radical with the atmospheric biogenics isoprene, alpha-pinene and delta-3-carene

et al. 2017

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“…Experimental studies of ozonolysis of sesquiterpenes, which showed that semi-volatile products were produced in gas-phase reactions, were limited to individual configurations [13,21]. Currently, no laboratory measurements and simulation have been performed to explain the field-based results that sesquiterpenes exerted negative effects on climate change because of their absorption in UV region [14,17,32]. In addition, information concerning the relationship between the electronic states and atmospheric reactivity of sesquiterpenes is also scarce.…”

Section: Introductionmentioning

confidence: 99%

UV-spectroscopy, electronic structure and ozonolytic reactivity of sesquiterpenes: a theoretical study

Zeng

2011

J Mol Model

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Sesquiterpenes, one of the most important classes of biogenic volatile organic compounds, are potentially significant precursors to secondary organic aerosols (SOAs) in nature. The electronic structure of sesquiterpenes and their reactivity in the ozonolysis reaction were investigated by density functional theory. Results from the CIS calculations combined with an analysis of transition intensities show that the first peaks in the ultraviolet (UV) spectra for saturated and unsaturated isomers are σ-σ* and π-π* transitions, respectively. The UV absorption wavelength and absorbency are dictated by the electronic structures of these compounds. An increase in the number of double bonds and formation of a conjugated system expand the range of absorption in the UV region. An isomer with an endocyclic C = C bond presents weaker UV transition intensity than its corresponding exocyclic isomer. Results from conceptual DFT chemical reactivity indices of isomers suggest that no quantitative linear relationships between the structural changes and their reactivity, such as different degrees of unsaturated C = C double bonds, or the number of substituents attached to the C = C bond were discovered. In the ozonolysis reaction of sesquiterpenes, isomers with larger steric hindrance of substituents or endocyclic C = C bond possess higher chemical reactivity compared to isomers with smaller steric hindrandce or with an exocyclic C = C bond. These results are imperative to a better understanding of SOAs production mechanisms in the troposphere.

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Experimental and Theoretical Investigation of the 3sp(d) Rydberg States of Fenchone by Polarized Laser Resonance‐Enhanced‐Multiphoton‐Ionization and Fourier Transform VUV Absorption Spectroscopy

et al. 2020

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The VUV absorption spectrum of fenchone is re‐examined using synchrotron radiation Fourier transform spectrometry, revealing new vibrational structure. Picosecond laser (2+1) resonance enhanced multiphoton ionization (REMPI) spectroscopy complements this, providing an alternative view of the 3spd Rydberg excitation region. These spectra display broadly similar appearance, with minor differences that are largely explained by referring to calculated one‐ and two‐photon electronic excitation cross‐sections. Both show good agreement with Franck‐Condon simulations of the relevant vibrational structures. Parent ion REMPI ionization yields with both femtosecond and picosecond excitation laser pulses are studied as a function of laser polarization and intensity, the latter providing insight into the relative two‐photon excitation and one‐photon ionization rates. The experimental circular‐linear dichroism observed in the parent ion yields varies strongly between the 3s and 3p Rydberg states, in good overall agreement with the calculated two‐photon excitation circular‐linear dichroism, while corroborating other evidence that the 3pz sub‐state plays no more than a very minor role in the (2+1) REMPI spectrum. Vibrationally resolved photoelectron spectra are recorded with picosecond pulse duration (2+1) REMPI at selected intermediate vibrational excitations. The 3s intermediate state displays a very strong Δv=0 propensity on ionization, but the 3p intermediate evidences more complex vibronic dynamics, and we infer some 3p→3s internal conversion prior to ionization.

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Electron impact ionisation and UV absorption study of α- and β-pinene

Cited by 21 publications

References 26 publications

Temperature-dependent rate coefficients for the reactions of the hydroxyl radical with the atmospheric biogenics isoprene, alpha-pinene and delta-3-carene

Temperature-dependent rate coefficients for the reactions of the hydroxyl radical with the atmospheric biogenics isoprene, alpha-pinene and delta-3-carene

UV-spectroscopy, electronic structure and ozonolytic reactivity of sesquiterpenes: a theoretical study

Experimental and Theoretical Investigation of the 3sp(d) Rydberg States of Fenchone by Polarized Laser Resonance‐Enhanced‐Multiphoton‐Ionization and Fourier Transform VUV Absorption Spectroscopy

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