Kinetics and products of the gas-phase reactions of divinyl sulfoxide with OH and NO3 radicals and O3

Using relative rate methods, rate constants for the gas-phase reactions of divinyl sulfoxide [CH 2CHS(O)CHCH 2; DVSO] with NO 3 radicals and O 3 have been measured at 296 +/- 2 K, and rate constants for the reaction with OH radicals have been measured over the temperature range of 277-349 K. Rate constants obtained for the NO 3 radical and O 3 reactions at 296 +/- 2 K were (6.1 +/- 1.4) x 10 (-16) and (4.3 +/- 1.0) x 10 (-19) cm (3) molecule (-1) s (-1), respectively. For the OH radical reaction, the temperature-dependent rate expression obtained was k = 4.17 x 10 (-12)e ((858 +/- 141)/ T ) cm (3) molecule (-1) s (-1) with a 298 K rate constant of (7.43 +/- 0.71) x 10 (-11) cm (3) molecule (-1) s (-1), where, in all cases, the errors are two standard deviations and do not include the uncertainties in the rate constants for the reference compounds. Divinyl sulfone was observed as a minor product of both the OH radical and NO 3 radical reactions at 296 +/- 2 K. Using in situ Fourier transform infrared spectroscopy, CO, CO 2, SO 2, HCHO, and divinyl sulfone were observed as products of the OH radical reaction, with molar formation yields of 35 +/- 11, 2.2 +/- 0.8, 33 +/- 4, 54 +/- 6, and 5.4 +/- 0.8%, respectively, in air. For the experimental conditions employed, aerosol formation from the OH radical-initiated reaction of DVSO in the presence of NO was minor, being approximately 1.5%. The data obtained here for DVSO are compared with literature data for the corresponding reactions of dimethyl sulfoxide.     

Kinetics of the gas-phase reactions of NO3 radicals and O3 with 3-methylfuran and the OH radical yield from the O3 reaction

Using relative rate methods, rate constants have been measured for the gas-phase reactions of 3-methylfuran with NO₃ radicals and O₃ at 296 ± 2 K and atmospheric pressure of air. The rate constants determined were (1.31 ± 0.461) × 10⁻¹¹ cm³ molecule⁻¹ s⁻¹ for the NO₃ radical reaction and (2.05 ± 0.52) × 10⁻¹⁷ cm³ molecule⁻¹ s⁻¹ for the O₃ reaction, where the indicated errors include the estimated overall uncertainties in the rate constants for the reference reactions. Based on the cyclohexanone plus cyclohexanol yield in the presence of sufficient cyclohexane to scavenge > 95% of OH radicals formed, it is estimated that the O₃ reaction leads to the formation of OH radicals with a yield of 0.59, uncertain to a factor of ca. 1.5. In the troposphere, 3-methylfuran will react dominantly with the OH radical during daylight hours, and with the NO₃ radical during nighttime hours for nighttime NO₃ radical concentrations > 10⁷ molecule cm ⁻³. © 1996 John Wiley & Sons, Inc.     

Kinetics and products of the gas-phase reactions of O3 with amines and related compounds

The kinetics and products of the gas-phase reactions of O₃ with a series of aliphatic amines and related compounds have been investigated at 298 ± 2 K and 740 Torr total pressure of air. The absolute rate constants obtained (in cm³ molecule^-1 s^-1 units) were: methylamine, (7.4 ± 2.4) x 10^-21; dimethylamine, (1.67 ± 0.20) x 10^-18; trimethylamine, (7.84 ± 0.87) x 10^-18; 2-(dimethylamino)ethanol, (6.76 ± 0.83) x 10^-18; and tetramethylhydrazine, (5.21 ± 0.60) x 10^-18. The major products observed from the O₃ reactions with the use of in situ FT-IR absorption spectroscopy were: from trimethylamine, (CH₃)₂NCHO, CH₃N=CH₂ and HCHO; and from dimethylamine, CH₃N=CH₂, CH₃NO₂, and HCHO. Possible reaction mechanisms are presented and discussed.     

Kinetics and products of the reactions of selected diols with the OH radical

Using a relative rate method, rate constants have been measured at 296 ± 2 K for the gas‐phase reactions of OH radicals with 1,2‐butanediol, 2,3‐butanediol, 1,3‐butanediol, and 2‐methyl‐2,4‐pentanediol, with rate constants (in units of 10^?12 cm³ molecule^?1 s^?1) of 27.0 ± 5.6, 23.6 ± 6.3, 33.2 ± 6.8, and 27.7 ± 6.1, respectively, where the error limits include the estimated overall uncertainty of ±20% in the rate constant for the reference compound. Gas chromatographic analyses showed the formation of 1‐hydroxy‐2‐butanone from 1,2‐butanediol, 3‐hydroxy‐2‐butanone from 2,3‐butanediol, 1‐hydroxy‐3‐butanone from 1,3‐butanediol, and 4‐hydroxy‐4‐methyl‐2‐pentanone from 2‐methyl‐2,4‐pentanediol, with formation yields of 0.66 ± 0.11, 0.89 ± 0.09, 0.50 ± 0.09, and 0.47 ± 0.09, respectively, where the indicated errors are the estimated overall uncertainties. Pathways for the formation of these products are presented, together with a comparison of the measured and estimated rate constants and product yields. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 310–316, 2001     

Nitroarene products from the gas-phase reactions of volatile polycyclic aromatic hydrocarbons with the OH radical and N2O5

The nitroarene products of the gas-phase reactions of acenaphthylene, acenaphthene, phenanthrene, and anthracene-d₁₀ with N₂O₅ and the OH radical (in the presence of NO_x) are reported. The calculated atmospheric lifetimes of these polycyclic aromatic hydrocarbons (PAH), as well as those of naphthalene, 1- and 2-methylnaphthalene, biphenyl, fluoranthene, pyrene, and acephenanthrylene, show that reaction with the OH radical is the dominant loss process for these PAH, with the exception of acenaphthylene, acenaphthene, and acephenanthrylene which contain an external cyclopenta-fused ring. For these latter PAH, reaction with the NO₃ radical, and for acenaphthylene and acephenanthrylene reaction with O₃, are also expected to be important atmospheric loss processes. The nitroarenes observed as products of the atmospherically-important gas-phase reactions of the PAH in environmental chamber studies are compared with the nitroarenes measured in ambient air samples collected in California. It is concluded that although nitroarenes are formed in low yields (?5%) from the OH radical-initiated reactions of the PAH, atmospheric formation of nitroarenes may contribute significantly to ambient nitroarene concentrations.     

Rate constants for the gas-phase reactions of O3 with a series of Terpenes and OH radical formation from the O3 reactions with Sesquiterpenes at 296 ± 2 K

Rate constants for the gas-phase reactions of O₃ with the sesquiterpenes α-cedrene, α-copaene, β-caryophyllene, α-humulene, and longifolene, and with the monoterpenes limonene, terpinolene, α-phellandrene, and α-terpinene, have been measured using a relative rate technique at 296 ± 2 K and atmospheric pressure of air. The rate constants obtained (in units of 10^?17 cm³ molecule^?1 s^?1) are: limonene, 20.1 ± 5.1; terpinolene, 188 ± 67; α-phellandrene, 298 ± 105; α-terpinene, 2110 ± 770; α-cedrene, 2.78 ± 0.71; α-copaene, 15.8 ± 5.6; β-caryophyllene, 1160 ± 430; α-humulene, 1170 ± 450; and longifolene, <0.07, where the indicated errors include the estimated overall uncertainties in the rate constants for the reference organics. Hydroxyl radical formation yields were also determined for the O₃ reactions with the sesquiterpenes, of 0.67 for α-cedrene, 0.35 for α-copaene, 0.06 for β-caryophyllene, and 0.22 for α-humulene, all with estimated overall uncertainties of a factor of ca. 1.5. The tropospheric lifetimes of the sesquiterpenes due to reaction with O₃ are calculated. © 1994 John Wiley & Sons, Inc.     

Kinetics and mechanisms of the gas-phase reactions of the NO3 radical with aromatic compounds

The kinetics and nitrated products of the gas-phase reactions of the NO₃ radical with methoxybenzene, 1,2-, 1,3-, and 1,4-dimethoxybenzene, dibenzofuran and dibenzo-p-dioxin have been investigated at 297 ± 2 K and in the presence of one atmosphere of air. A relative rate method was used for the kinetic measurements. No reactions of methoxybenzene or dibenzofuran with the NO₃ radical were observed. The dimethoxybenzenes were observed to react by H-atom abstraction and NO₃ radical addition to the aromatic ring, while dibenzo-p-dioxin reacted by NO₃ radical addition to the aromatic rings. For these compounds, the NO₃ radical addition pathways were observed to be reversible. At the NO₂ concentrations employed, the NO₃-aromatic adducts reacted with NO₂ and the observed rate constants increased with increasing NO₂ concentration. However, for dibenzo-p-dioxin the observed rate constant became independent of the NO₂ concentration for concentrations ≥ 4.8 × 10¹³ molecule cm^?3, and under these conditions the rate constant of 6.8 × 10^?14 cm³ molecule^?1 s^?1 was taken to be that for addition of the NO₃ radical to the aromatic rings. The proposed NO₃ radical reaction mechanisms are discussed. © 1994 John Wiley & Sons, Inc.     

Kinetics of the gas-phase reactions of β-phellandrene with OH and NO3 radicals and O3 at 297 ± 2 K

Rate constants for the gas-phase reactions of the biogenically emitted monoterpene β-phellandrene with OH and NO₃ radicals and O₃ have been measured at 297 ± 2 K and atmospheric pressure of air using relative rate methods. The rate constants obtained were (in cm³ molecule^?1 s^?1 units): for reaction with the OH radical, (1.68 ± 0.41) × 10^?10; for reaction with the NO₃ radical, (7.96 ± 2.82) × 10^?12; and for reaction with O₃, (4.77 ± 1.23) × 10^?17, where the error limits include the estimated uncertainties in the reference reaction rate constants. Using these rate constants, the lifetime of β-phellandrene in the lower troposphere due to reaction with these species is calculated to be in the range of ca. 1–8 h, with the OH radical reaction being expected to dominate over the O₃ reaction as a loss process for β-phellandrene during daylight hours.     

Kinetics of OH radical reactions with a series of ethers

The rate constants for the reactions of OH with dimethyl ether (k₁), diethyl ether (k₂), di-n-propyl ether (k₃), di-isopropyl ether (k₄), and di-n-butyl ether (k₅) have been measured over the temperature range 230–372 K using the pulsed laser photolysis-laser induced fluorescence (PLP-LIF) technique. The temperature dependence of k₁,k₄, can be expressed in the Arrhenius plots form: k₁ = (6.30 ± 0.10) × 10^?12 exp[?(234 ± 34)/T] and k₄ = (4.13 ± 0.10) × 10^?12 exp[(274 ± 26)/T]. The Arrhenius plots for k₂,k₃, and k₅, were curved and they were fitted to the three parameter expressions: k₂ = (1.02 ± 0.08) × 10^?17 T² exp[(797 ± 24)/T], k₃ = (1.84 ± 0.23) × 10^?17T² exp[(767 ± 34)/T], and k₅ = (6.29 ± 0.74) × 10^?18T² exp[(1164 ± 34)/T]. The values at 298 K are (2.82 ± 0.21) × 10^?12, (1.36 ± 0.11) × 10^?11,(2.17 ± 0.16) × 10^?11, (1.02 ± 0.10) × 10^?11, and (2.69 ± 0.22) × 10^?11 for k₁, k₂, k₃, k₄, and k₅, respectively, (in cm³ molecule^?1 s^?1). These results are compared to the literature data. © 1995 John Wiley & Sons, Inc.     

High temperature study of the reactions of O and OH with NH3

Mixtures of NH₃ and N₂O dilute in Ar were heated behind incident shock waves in the temperature range 1750–2060 K. A cw ring dye laser, tuned to the center of an OH absorption line in the ultraviolet, was used to monitor OH concentration profiles by absorption spectroscopy. Infrared emission was used to follow N₂O (at 4.5 μm) and NH₃ (at 10.5 μm) concentration—time histories. The early-time NH₃ and OH concentration profiles were sensitive to the rate constants of the reactions leading to the following best-fit expressions for k₂ and k₃:k₂ = 10^13.34±0.3 exp(?4470/T) and k₃ = 10^13.91±0.2 exp(-4230/T) cm³ mol^?1 s^?1. The results of this study combined with previous low-temperature data suggest a significant non-Arrhenius behavior for both k₂ and k₃.     

Kinetic study of the gas-phase reactions of OH and NO3 radicals and O3 with selected vinyl ethers

Kinetic studies on the gas-phase reactions of OH and NO3 radicals and ozone with ethyl vinyl ether (EVE), propyl vinyl ether (PVE) and butyl vinyl ether (BVE) have been performed in a 405 L borosilicate glass chamber at 298 +/- 3 K in synthetic air using in situ FTIR spectroscopy to monitor the reactants. Using a relative kinetic method rate coefficients (in units of cm3 molecule(-1) s(-1)) of (7.79 +/- 1.71) x 10(-11), (9.73 +/- 1.94) x 10(-11) and (1.13 +/- 0.31) x 10(-10) have been obtained for the reaction of OH with EVE, PVE and BVE, respectively, (1.40 +/- 0.35) x 10(-12), (1.85 +/- 0.53) x 10(-12) and (2.10 +/- 0.54) x 10(-12) for the reaction of NO3 with EVE, PVE and BVE, respectively, and (2.06 +/- 0.42) x 10(-16), (2.34 +/- 0.48) x 10(-16) and (2.59 +/- 0.52) x 10(-16) for the ozonolysis of EVE, PVE and BVE, respectively. Tropospheric lifetimes of EVE, PVE and BVE with respect to the reactions with reactive tropospheric species (OH, NO3 and O3) have been estimated for typical OH and NO3 radical and ozone concentrations.     

Practical Os/Cu-cocatalyzed air oxidation of allyl and benzyl alcohols at room temperature and atmospheric pressure

[reaction: see text] A new protocol for the oxidation of primary and secondary allyl and benzyl alcohols at room temperature and using 1 atm of air is described. The procedure uses low loadings of copper salts and osmium tetroxide, which is activated with quinuclidine and prereduced with an alkene. Chemoselectivity for allyl and benzyl alcohols is very high, no overoxidation is observed, and the reaction takes place under neutral conditions.     

Rate constants for the gas-phase reactions of selected dibasic esters with the OH radical

Using a relative rate method, rate constants have been measured for the gas-phase reactions of the OH radical with the dibasic esters dimethyl succinate [CH₃OC(O)CH₂CH₂C(O)OCH₃], dimethyl glutarate [CH₃OC(O)CH₂CH₂CH₂C(O)OCH₃], and dimethyl adipate [CH₃OC(O)CH₂CH₂CH₂CH₂C(O)OCH₃] at 298±3 K. The rate constants obtained were (in units of 10⁻¹² cm³ molecule⁻¹ s⁻¹): dimethyl succinate, 1.4±0.6; dimethyl glutarate, 3.3±1.1; and dimethyl adipate, 8.4±2.5, where the indicated errors include the estimated overall uncertainty of ±25% in the rate constant for cyclohexane, the reference compound. The calculated tropospheric lifetimes of these dibasic esters due to gas-phase reaction with the OH radical range from 1.4 days for dimethyl adipate to 8.3 days for dimethyl succinate for a 24 h average OH radical concentration of 1.0×10⁶ molecule cm⁻³. © 1998 John Wiley & Sons, Inc. Int J Chem Kinet: 30: 471–474, 1998     

Kinetics of the gas-phase reactions of OH radicals with alkyl nitrates at 299 ± 2 K

Relative rate constants for the gas-phase reactions of OH radicals with a series of alkyl nitrates have been determined at 299 ± 2 K, using methyl nitrite photolysis in air as a source of OH radicals. Using a rate constant for the reaction of OH radicals with cyclohexane of 7.57 × 10^?12 cm³/molec·s, the rate constants obtained are (× 10¹² cm³/molec·s): 2-propyl nitrate, 0.18 ± 0.05; 1-butyl nitrate, 1.42 ± 0.11; 2-butyl nitrate, 0.69 ± 0.10; 2-pentyl nitrate, 1.87 ± 0.12; 3-pentyl nitrate, 1.13 ± 0.20; 2-hexyl nitrate, 3.19 ± 0.16; 3-hexyl nitrate, 2.72 ± 0.22; 3-heptyl nitrate, 3.72 ± 0.43; and 3-octyl nitrate, 3.91 ± 0.80. These rate constants, which are the first reported for the alkyl nitrates, are significantly lower than those for the parent alkanes, and a formula, based on the numbers of the various types of C? H bonds in the alkyl nitrates, is derived for rate constant estimation purposes.     

Kinetics of the gas-phase reactions of indan,indene, fluorene,and 9,10-dihydroanthracene with OH radicals,NO3 radicals,and O3

The kinetics of the gas-phase reactions of OH radicals, NO₃ radicals, and O₃ with indan, indene, fluorene, and 9,10-dihydroanthracene have been studied at 297 ± 2 K and atmospheric pressure of air. The rate constants, or upper limits thereof, for the O₃ reactions were (in cm³ molecule⁻¹ s⁻¹ units): indan, < 3 × 10⁻¹⁹; indene, (1.7 ± 0.5) × 10⁻¹⁶, fluorene, < 2 × 10⁻¹⁹; and 9,10-dihydroanthracene, (9.0 ± 2.0) × 10⁻¹⁹. Using a relative rate method, the rate constants for the OH radical and NO₃ radical reactions, respectively, were (in cm³ molecule⁻¹ s⁻¹ units): indan, (1.9 ± 0.5) × 10⁻¹¹ and (6.6 ± 2.0) × 10⁻¹⁵; indene, (7.8 ± 2.0) × 10⁻¹¹ and (4.1 ± 1.5) × 10⁻¹²; fluorene, (1.6 ± 0.5) × 10⁻¹¹ and (3.5 ± 1.2) × 10⁻¹⁴; and 9,10-dihydroanthracene, (2.3 ± 0.6) × 10⁻¹¹ and (1.2 ± 0.4) × 10⁻¹². These kinetic data were used to assess the relative contributions of the various reaction pathways. © 1997 John Wiley & Sons, Inc. Int J Chem Kinet 29: 299–309, 1997.     

Kinetics of the gas-phase reactions of the OH radical with (C2H5)3PO and (CH3O)2P(S)Cl at 296 ± 2 K

The kinetics of the gas-phase reactions of the OH radical with (C₂H₅O)₃PO and (CH₃O)₂P(S)Cl and of the reactions of NO₃ radicals and O₃ with (CH₃O)₂P(S)Cl have been studied at room temperature. Using a relative rate technique, the rate constants determined for the reactions of the OH radical with (C₂H₅O)₃PO and (CH₃O)₂P(S)Cl at 296 ± 2 K and 740 torr total pressure of air were (5.53 ± 0.35) × 10^?11 and (5.96 ± 0.38) × 10^?11 cm³ molecule^?1 s^?1, respectively. Upper limits to the rate constants for the NO₃ radical and O₃ reactions with (CH₃O)₂P(S)Cl of <3 × 10^?14 cm³ molecule^?1 s^?1 and <2 × 10^?19 cm³ molecule^?1 s^?1, respectively, were obtained. These data are compared and discussed with previous literature data for organophosphorus compounds.     

Kinetics of the gas-phase reaction of OH with HCl

The reaction of hydroxyl radicals with hydrogen chloride (reaction 1) has been studied experimentally using a pulsed-laser photolysis/pulsed-laser-induced fluorescence technique over a wide range of temperatures, 298-1015 K, and at pressures between 5.33 and 26.48 kPa. The bimolecular rate coefficient data set obtained for reaction 1 demonstrates no dependence on pressure and exhibits positive temperature dependence that can be represented with modified three-parameter Arrhenius expression within the experimental temperature range: k1 = 3.20 x 10(-15)T0.99 exp(-62 K/T) cm3 molecule(-1) s(-1). The potential-energy surface has been studied using quantum chemical methods, and a transition-state theory model has been developed for the reaction 1 on the basis of calculations and experimental data. The model results in modified three-parameter Arrhenius expressions: k1 = 8.81 x 10(-16)T1.16 exp(58 K/T) cm3 molecule(-1) s(-1) for the temperature range 200-1015 K and k1 = 6.84 x 10(-19)T2.12 exp(646 K/T) cm3 molecule(-1) s(-1) for the temperature dependence of the reaction 1 rate coefficient extrapolation to high temperatures (500-3000 K). A temperature dependence of the rate coefficient of the Cl + H2O --> HCl + OH reaction has been derived on the basis of the experimental data, modeling, and thermochemical information.     

Rate constants for the gas-phase reactions of cis-3-Hexen-1-ol,cis-3-Hexenylacetate,trans-2-Hexenal,and Linalool with OH and NO3 radicals and O3 at 296 ± 2 K,and OH radical formation yields from the O3 reactions

Rate constants for the gas-phase reactions of the four oxygenated biogenic organic compounds cis-3-hexen-1-ol, cis-3-hexenylacetate, trans-2-hexenal, and linalool with OH radicals, NO₃ radicals, and O₃ have been determined at 296 ± 2 K and atmospheric pressure of air using relative rate methods. The rate constants obtained were (in cm³ molecule^?1 s^?1 units): cis-3-hexen-1-ol: (1.08 ± 0.22) × 10^?10 for reaction with the OH radical; (2.72 ± 0.83) × 10^?13 for reaction with the NO₃ radical; and (6.4 ± 1.7) × 10^?17 for reaction with O₃; cis-3-hexenylacetate: (7.84 ± 1.64) × 10^?11 for reaction with the OH radical; (2.46 ± 0.75) × 10^?13 for reaction with the NO₃ radical; and (5.4 ± 1.4) × 10^?17 for reaction with O₃; trans-2-hexenal: (4.41 ± 0.94) × 10^?11 for reaction with the OH radical; (1.21 ± 0.44) × 10^?14 for reaction with the NO₃ radical; and (2.0 ± 1.0) × 10^?18 for reaction with O₃; and linalool: (1.59 ± 0.40) × 10^?10 for reaction with the OH radical; (1.12 ± 0.40) × 10^?11 for reaction with the NO₃ radical; and (4.3 ± 1.6) × 10^?16 for reaction with O₃. Combining these rate constants with estimated ambient tropospheric concentrations of OH radicals, NO₃ radicals, and O₃ results in calculated tropospheric lifetimes of these oxygenated organic compounds of a few hours. © 1995 John Wiley & Sons, Inc.     

Kinetics of the reactions of O3 and OH radicals with furan and thiophene at 298 ± 2 K

Rate constants for the reactions of O₃ and OH radicals with furan and thiophene have been determined at 298 ± 2 K. The rate constants obtained for the O₃ reactions were (2.42 ± 0.28) × 10^?18 cm³/molec·s for furan and <6 ×10^?20 cm³/molec·s for thiophene. The rate constants for the OH radical reactions, relative to a rate constant for the reaction of OH radicals with n-hexane of (5.70 ± 0.09) × 10^?12 cm³/molec·s, were determined to be (4.01 ± 0.30) × 10^?11 cm³/molec·s for furan and (9.58 ± 0.38) × 10^?12 cm³/molec·s for thiophene. There are to date no reported rate constant data for the reactions of OH radicals with furan and thiophene or for the reaction of O₃ with furan. The data are compared and discussed with respect to those for other alkenes, dialkenes, and heteroatom containing organics.     

Mechanism of OH radical reactions with HCN and CH3CN: OH regeneration in the presence of O2

A theoretical study on the mechanism of the OH reactions with HCN and CH(3)CN, in the presence of O2, is presented. Optimum geometries and frequencies have been computed at BHandHLYP/6-311++G(2d,2p) level of theory for all stationary points. Energy values have been improved by single-point calculations at the above geometries using CCSD(T)/6-311++G(2d,2p). The initial attack of OH to HCN was found to lead only to the formation of the HC(OH)N adduct, while for CH(3)CN similar proportions of CH(2)CN and CH(3)C(OH)N are expected. A four-step mechanism has been proposed to explain the OH regeneration, experimentally observed for OH + CH(3)CN reaction, when carried out in the presence of O2. The mechanism steps are as follows: (1) OH addition to the C atom in the CN group, (2) O2 addition to the N atom, (3) an intramolecular H migration from OH to OO, and (4) OH elimination. This mechanism is in line with the one independently proposed by Wine et al. for HCN. The results obtained here suggest that for the OH + HCN reaction, the OH regeneration might occur even in larger extension than for OH + CH(3)CN reaction. The agreement between the calculated data and the available experimental evidence on the studied reactions seems to validate the mechanism proposed here.