| Popis: |
The kinetics of the gas-phase reactions of O 3 with a series of selected terpenes has been investigated under flow-tube conditions at a pressure of 100 mbar synthetic air at 295 ′ 0.5 K. In the presence of a large excess of m-xylene as an OH radical scavenger, rate coefficients k(O 3 +terpene) were obtained with a relative rate technique, (unit: cm 3 molecule - 1 s - 1 , errors represent 2a): α-pinene: (1.1 ′ 0.2) x 10 - 1 6 , 3 Δ-carene: (5.9 ′ 1.0) x 10 - 1 7 , limonene: (2.5 ′ 0.3) × 10 - 1 6 , myrcene: (4.8 ′ 0.6) x 10 - 1 6 , trans-ocimene: (5.5 ′ 0.8) x 10 - 1 6 , terpinolene: (1.6 ′ 0.4) x 10 - 1 5 and α-terpinene: (1.5 ′ 0.4) x 10 - 1 4 . Absolute rate coefficients for the reaction of O 3 with the used reference substances (2-methyl-2-butene and 2,3-dimethyl-2-butene) were measured in a stopped-flow system at a pressure of 500 mbar synthetic air at 295 ′ 2 K using FT-IR spectroscopy, (unit: cm 3 molecule - 1 s - 1 , errors represent 2σ): 2-methyl-2-butene: (4.1 ′ 0.5) x 10 - 1 6 and 2,3-dimethyl-2-butene: (1.0 ′ 0.2) x 10 - 1 5 . In addition, OH radical yields were found to be 0.47 ′ 0.04 for 2-methyl-2-butene and 0.77 ′ 0.04 for 2,3-dimethyl-2-butene. |
Plný text