National Institute for Environment Studies, Tsukuba, Ibaraki 305-8506, Japan.
J Phys Chem A. 2012 Aug 23;116(33):8523-9. doi: 10.1021/jp303202h. Epub 2012 Aug 10.
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.
在 760 托和 298 K 的条件下，使用 6 立方米光化学反应室测量了（Z）-3-己烯（3HA）光解（J（1））、与 OH 自由基反应（k（2））和与臭氧反应（k（3））这三个日间大气反应的速率系数。在 240-350nm 的波长范围内获得了 3HA 的紫外吸收截面（σ（3HA）（λ））。3HA 相对于 NO2 的光分解速率通过太阳能模拟器在 760 托下进行测量，结果为 J（1）/J（NO2）=（4.7±0.4）×10（-3）。利用得到的 σ（3HA）（λ）和 J（1）/J（NO2），计算出有效光分解量子产率为 Φ（3HA）=0.25±0.06。通过相对速率法，用三种参考化合物测量了与 OH 自由基的反应速率系数，并确定为 k（2）=（6.9±0.9）×10（-11）cm3 分子（-1）s（-1）。通过绝对法测量了与臭氧的反应速率系数，并确定为 k（3）=（3.5±0.2）×10（-17）cm3 分子（-1）s（-1）。利用得到的速率系数，估算了 3HA 的日间大气寿命。
