Kinetic study of the daytime atmospheric fate of (Z)-3-hexenal.
Rate coefficients for three daytime atmospheric reactions of (Z)-3-hexenal (3HA)-photolysis (J(1)), reaction with OH radicals (k(2)), and reaction with ozone (k(3))-were measured at 760 Torr and 298 K using a 6 m(3) photochemical reaction chamber. The UV absorption cross sections (σ(3HA)(λ)) were obtained in the wavelength range 240-350 nm. The photodissociation rate of 3HA relative to that of NO(2) was measured by a solar simulator at 760 Torr and was determined to be J(1)/J(NO2) = (4.7 ± 0.4) × 10(-3). Using the obtained σ(3HA)(λ) and J(1)/J(NO2), the effective photodissociation quantum yield was calculated to be Φ(3HA) = 0.25 ± 0.06. The rate coefficient for the reaction with OH radicals was measured by the relative rate method with three reference compounds and was determined to be k(2) = (6.9 ± 0.9) × 10(-11) cm(3) molecule(-1) s(-1). The rate coefficient for the reaction with ozone was measured by an absolute method and was determined to be k(3) = (3.5 ± 0.2) × 10(-17) cm(3) molecule(-1) s(-1). Using the obtained rate coefficients, the daytime atmospheric lifetime of 3HA was estimated.
National Institute for Environment Studies, Tsukuba, Ibaraki 305-8506, Japan.
Jia-Hua
JH
Xing
Miyuki
M
Ono
Ayako
A
Kuroda
Kinichi
K
Obi
Kei
K
Sato
Takashi
T
Imamura
D000447:Aldehydes / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D007700:Kinetics; D010126:Ozone / Q000737:chemistry; D010782:Photolysis; D013056:Spectrophotometry, Ultraviolet
D000447:Aldehydes; D017665:Hydroxyl Radical; D010126:Ozone; C010463:n-hexanal