PRODUCTS AND MECHANISM OF THE GAS-PHASE REACTION OF NO3 RADICALS WITH ALPHA -PINENE

The gas-phase reaction of NO 3 radicals with α-pinene has been studied under flow conditions in the pressure range 20<p/mbar <200 at 298 K using gas chromatography–mass spectrometry/flame ionisation detection (GC–MS/FID), MS and long-path FTIR spectroscopy as detection techniques. NO 3 radicals were generated by thermal decomposition of N 2 O 5 . He, N 2 or O 2 –N 2 mixtures served as carrier gas. In the absence of O 2 in the carrier gas, α-pinene oxide (ca. 60%) and an organic nitrate (ca. 40%) were found to be the main products with minor amounts of α-campholene aldehyde. The yields were slightly pressure dependent. In the presence of O 2 , pinonaldehyde was the predominant product. When NO was added for conversion of the formed peroxyl radicals via RO 2 +NO→RO→NO 2 , the following product yields were obtained at p=200 mbar and [O 2 ]>10 17 molecule cm -3 , pinonaldehyde 75±6%, α-pinene oxide 15±3%, organic nitrates (total) 14±3%, α-campholene aldehyde 3±1%. In the absence of NO, nitroperoxy-group-containing substances were observed, arising from the reaction RO 2 +NO 2 →RO 2 NO 2 . A reaction mechanism is proposed and a tropospheric application of the results is discussed.

[1]  W. Rolle†,et al.  Products of the Gas-Phase Reactions of NO3 Radicals with Furan and Tetramethylfuran , 1997 .

[2]  Correction to ``Effect of peroxy radical reactions on the predicted concentrations of ozone, nitrogenous compounds, and radicals'' , 1996 .

[3]  V. Daële,et al.  Kinetic Study of the Reactions of C2H5O and C2H5O2 with NO3 at 298 K , 1996 .

[4]  W. Rolle†,et al.  Reaction of NO3 Radicals with 1,3‐Cyclohexadiene, α‐Terpinene, and α‐Phellandrene: Kinetics and Products , 1996 .

[5]  T. Berndt,et al.  Products and mechanism of the reaction of NO3 with selected acyclic monoalkenes , 1995 .

[6]  R. N. Schindler,et al.  REMPI-MS and FTIR Study of NO2 and Oxirane Formation in the Reactions of Unsaturated Hydrocarbons with NO3 Radicals , 1994 .

[7]  R. N. Schindler,et al.  On the pressure dependence of the NO2 product yield in the reaction of NO3 radicals with selected alkenes , 1994 .

[8]  T. Berndt,et al.  Kinetics of oxirane formation in the reaction of nitrate radicals with tetramethylethylene , 1994 .

[9]  R. N. Schindler,et al.  On the identification of oxiranes formed in the reactions of NO3 radicals with alkenes , 1993 .

[10]  I. Wängberg.  Mechanisms and products of the reactions of NO3 with cycloalkenes , 1993 .

[11]  M. Molina,et al.  High pressure fast‐flow technique for gas phase kinetics studies , 1993 .

[12]  M. Jenkin,et al.  Kinetics and product study of the self-reactions of allyl and allyl peroxy radicals at 296 K , 1993 .

[13]  R. A. Cox,et al.  Organic peroxy radicals: Kinetics, spectroscopy and tropospheric chemistry , 1992 .

[14]  R. Atkinson.  Kinetics and Mechanisms of the Gas‐Phase Reactions of the NO3 Radical with Organic Compounds , 1991 .

[15]  J. Burrows,et al.  The nitrate radical: Physics, chemistry, and the atmosphere , 1991 .

[16]  I. Barnes,et al.  Kinetics and products of the reactions of nitrate radical with monoalkenes, dialkenes, and monoterpenes , 1990 .

[17]  S. M. Aschmann,et al.  Rate constants for the gas-phase reactions of OH and NO3 radicals and O3 with sabinene and camphene at 296±2 K , 1990 .

[18]  R. Atkinson.  Gas-phase tropospheric chemistry of organic compounds: a review , 1990 .

[19]  E. H. Fink,et al.  Thermal decomposition of alkyl peroxynitrates , 1989 .

[20]  E. Dlugokencky,et al.  Studies of nitrate radical reactions with some atmospheric organic compounds at low pressures , 1989 .

[21]  L. Stieglitz,et al.  The gas phase addition of NOx to olefins , 1989 .

[22]  H. Akimoto,et al.  Ozone-cyclohexene reaction in air: quantitative analysis of particulate products and the reaction mechanism , 1985 .

[23]  D. E. Willis,et al.  Calculation of Flame Ionization Detector Relative Response Factors Using the Effective Carbon Number Concept , 1985 .

[24]  A. Winer,et al.  Gaseous Nitrate Radical: Possible Nighttime Atmospheric Sink for Biogenic Organic Compounds , 1984, Science.

[25]  P. Crutzen,et al.  Estimates on the production of CO and H2 from the oxidation of hydrocarbon emissions from vegetation , 1978 .

[26]  D. Albritton,et al.  Rate constants for the reactions of O2+, NO2+, NO+, H3O+, CO3−, NO2−, and halide ions with N2O5 at 300 K , 1978 .

[27]  B. Arbusow.  Studium der Isomerisation von Terpen‐oxyden, I. Mitteil.: Isomerisation des α‐Pinen‐oxydes bei der Reaktion von Reformatsky , 1935 .