title: Kinetics study of reactions of α-pinene and β-pinene with hydroxyl radical at 1-8 Torr and 240-340 K using the relative rate/discharge flow/mass spectrometry method.
abstract: The kinetics of reactions of α-pinene and β-pinene with hydroxyl radicals (OH) has been investigated at 1-8 Torr and 240-340 K using the relative rate/discharge flow/mass spectrometry (RR/DF/MS) technique. Our kinetic results indicate that at 298 K the rate constant of the reactions of α-pinene and β-pinene with hydroxyl radicals has little pressure dependence over the 1-8 Torr pressure range, suggesting that the high pressure limit of these reactions has been reached at 1 Torr. The rate constant of these reactions was found to negatively depend on the temperature at 240-340 K, which is consistent with previous investigations using different techniques. The Arrhenius equation for α-pinene and β-pinene with hydroxyl radical was determined to be k(α-pinene) = (1.21 ± 0.20) × 10(-11)exp[(441 ± 46)/T] cm(3) molecule(-1) s(-1) and k(β-pinene) = (1.65 ± 0.10) × 10(-11)exp[(470 ± 17)/T] cm(3) molecule(-1) s(-1), respectively. Using the rate constant determined at 277 K in this work and the average global hydroxyl radical concentration, the atmospheric lifetime of α-pinene and β-pinene was estimated to be 5.8 and 3.8 h, respectively.
authors.affiliation: Department of Chemistry and Biochemistry, California State University-Fullerton, Fullerton, California 92834, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Montenegro
authors.forename: Jacob S A
authors.initials: JS
authors.lastname: Ishibashi
authors.forename: Phuong
authors.initials: P
authors.lastname: Lam
authors.forename: Zhuangjie
authors.initials: Z
authors.lastname: Li
mesh_terms: D000081008:Bicyclic Monoterpenes; D001643:Bridged Bicyclo Compounds / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry*; D007700:Kinetics; D013058:Mass Spectrometry; D008968:Molecular Conformation; D039821:Monoterpenes / Q000737:chemistry*; D011312:Pressure; D013696:Temperature
chemical_list: D000081008:Bicyclic Monoterpenes; D001643:Bridged Bicyclo Compounds; D039821:Monoterpenes; D017665:Hydroxyl Radical; C010789:beta-pinene; C005451:alpha-pinene