Rate constants for the gas‐phase reactions of the OH radical with a series of monoterpenes at 294 ± 1 K

Atkinson, Roger; Aschmann, Sara M.; Pitts, James N.

doi:10.1002/kin.550180303

Cited by 88 publications

(91 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Regarding k 2 , there is excellent agreement between the results of this work and those obtained by the relative-rate technique (Atkinson et al, 1986;Gill and Hites, 2002;Montenegro et al, 2012;Winer et al, Table 3) and the 44 determinations of k 2 (297-364 K) from Gill and Hites (2002), which are instead represented (purple dotted line) by a fit with (Eq. 4).…”

Section: Comparison Of K 1 With Literature Valuessupporting

confidence: 78%

“…Within combined uncertainties there is reasonable agreement between this result and three previous absolute kinetic studies of (R2) (Chuong et al, 2002;Davis and Stevens, 2005;Kleindienst et al, 1982), all of which relied on manometric determinations of [α-pinene] to derive k 2 . The IUPAC data evaluation panel currently recommends a value of k 2 (298 K) = 5.3 × 10 −11 cm 3 molecule −1 s −1 (Ammann et al, 2016;Atkinson et al, 2006b), based on results from Atkinson et al (1986), Gill and Hites (2002) and Kleindienst et al (1982), with an associated log k 2 = 0.15 or approximately + 40, −30 %. A re-evaluation taking into account the data from this work and from the recent (Montenegro et al, 2012) study yields (via a weighted mean) k 2 (298 K) = 5.4 × 10 −11 cm 3 molecule −1 s −1 ; a considerably smaller log(k 2 ) of 0.06 (around ±15 %) would encompass all experimentally determined ambient temperature k 2 values.…”

Section: Comparison Of K 1 With Literature Valuesmentioning

confidence: 99%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

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.

show abstract

Section: Comparison Of K 1 With Literature Valuessupporting

confidence: 78%

Section: Comparison Of K 1 With Literature Valuesmentioning

confidence: 99%

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

View full text Add to dashboard Cite

show abstract

“…Multiplying the mixing ratios of these compounds by their OH rate constants provides a measure of relative OH reactivities Fantechi et al, 1998;Ravishankara and Davis, 1978;Atkinson et al, 1986Atkinson et al, , 1997Baulch et al, 1994;Huang et al, 2009;Picquet et al, 1998). We utilized fluxes instead of concentrations to provide a measure of OH reactivity that is independent of elevated concentrations associated with pollution events and more representative of site-specific sources.…”

Section: In the Context Of Prior Beachon Campaignsmentioning

confidence: 99%

Ethene, propene, butene and isoprene emissions from a ponderosa pine forest measured by relaxed eddy accumulation

et al. 2017

View full text Add to dashboard Cite

Abstract. Alkenes are reactive hydrocarbons that influence local and regional atmospheric chemistry by playing important roles in the photochemical production of tropospheric ozone and in the formation of secondary organic aerosols. The simplest alkene, ethene (ethylene), is a major plant hormone and ripening agent for agricultural commodities. The group of light alkenes (C 2 -C 4 ) originates from both biogenic and anthropogenic sources, but their biogenic sources are poorly characterized, with limited field-based flux observations. Here we report net ecosystem fluxes of light alkenes and isoprene from a semiarid ponderosa pine forest in the Rocky Mountains of Colorado, USA using the relaxed eddy accumulation (REA) technique during the summer of 2014. Ethene, propene, butene and isoprene emissions have strong diurnal cycles, with median daytime fluxes of 123, 95, 39 and 17 µg m −2 h −1 , respectively. The fluxes were correlated with each other, followed general ecosystem trends of CO 2 and water vapor, and showed similar sunlight and temperature response curves as other biogenic VOCs. The May through October flux, based on measurements and modeling, averaged 62, 52, 24 and 18 µg m −2 h −1 for ethene, propene, butene and isoprene, respectively. The light alkenes contribute significantly to the overall biogenic source of reactive hydrocarbons: roughly 18 % of the dominant biogenic VOC, 2-methyl-3-buten-2-ol. The measured ecosystem scale fluxes are 40-80 % larger than estimates used for global emissions models for this type of ecosystem.

show abstract

“…During the night, the absolute concentrations of isoprene, monoterpenes and OVOCs were reduced relative to the daytime, and the fraction of volatile organic carbon supplied as OVOCs and monoterpenes increased, to 35 % and 20 % respectively, while the isoprene contribution decreased, to 13 %. The reactivity of each VOC with respect to OH was calculated for each instantaneous measured mixing ratio as the product of the VOC concentration (converted from ppt to molec cm −3 ) and the relevant published rate constant, k OH (cm 3 molec −1 s −1 ) (Atkinson et al, 1986;Atkinson, 1997;Atkinson and Arey, 2003). Figure 7 shows the average day and night resolved distribution of the total OH reactivity with respect to VOCs, based upon all measurements from OP3-III.…”

Section: Voc Carbon Budget and Oh Reactivity Within The Natural Rainfmentioning

confidence: 99%

In situ measurements of isoprene and monoterpenes within a south-east Asian tropical rainforest

2011

View full text Add to dashboard Cite

Abstract. Biogenic volatile organic compounds (BVOCs) emitted from tropical rainforests comprise a substantial fraction of global atmospheric VOC emissions, however there are only relatively limited measurements of these species in tropical rainforest regions. We present observations of isoprene, α-pinene, camphene, -3-carene, γ -terpinene and limonene, as well as oxygenated VOCs (OVOCs) of biogenic origin such as methacrolein, in ambient air above a tropical rainforest in Malaysian Borneo during the Oxidant and Particle Photochemical Processes above a south-east Asian tropical rainforest (OP3) project in 2008. Daytime composition was dominated by isoprene, with an average mixing ratio of the order of ∼1 ppb. γ -terpinene, limonene and camphene were the most abundant monoterpenes, with average daytime mixing ratios of 102, 71 and 66 ppt respectively, and with an average monoterpene toisoprene ratio of 0.3 during sunlit hours, compared to 2.0 at night. Limonene and camphene abundances were seen to be related to both temperature and light conditions. In contrast, γ -terpinene emission continued into the late afternoon/evening, under relatively low temperature and light conditions. The contributions of isoprene, monoterpenes and other classes of VOC to the volatile carbon budget and OH reactivity have been summarised for this rainforest location. We observe good agreement between surface and aircraft measurements of boundary layer isoprene and methacrolein above the natural rainforest, suggesting that the ground-level observations are broadly representative of isoprene emissions from this region.

show abstract

Rate constants for the gas‐phase reactions of the OH radical with a series of monoterpenes at 294 ± 1 K

Cited by 88 publications

References 30 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

Ethene, propene, butene and isoprene emissions from a ponderosa pine forest measured by relaxed eddy accumulation

In situ measurements of isoprene and monoterpenes within a south-east Asian tropical rainforest

Contact Info

Product

Resources

About