Temperature dependence of the rate coefficient for the alpha-pinene reaction with ozone in the range between 243 K and 303 K.
The absolute rate coefficient for the reaction of alpha-pinene with ozone was determined in the temperature range between 243 K and 303 K at atmospheric pressure. In total, 30 experiments were performed in the large (85 m3) temperature-controlled simulation chamber AIDA, where the concentrations of the reactants ozone and alpha-pinene were measured directly. An Arrhenius expression for the alpha-pinene + ozone reaction was derived with a pre-exponential factor of (1.4 +/- 0.4) x 10(-15) cm3 s(-1) and a temperature coefficient of (833 +/- 86) K. This rate coefficient is in good agreement (-5%) with the current IUPAC (IUPAC 2007) recommendation at 298 K. The IUPAC recommendation is significantly larger (+27%), around 243 K where the recommended values were extrapolated from higher temperatures. This finding is relevant for tropical regions where strong updrafts can rapidly transport reactive hydrocarbons like alpha-pinene from the boundary layer into the cold regions of the free troposphere.
Tillmann
Ralf
R
Institut für Chemie und Dynamik der Geosphäre 2: Troposphäre, Forschungszentrum Jülich, Germany.
Saathoff
Harald
H
Brauers
Theo
T
Kiendler-Scharr
Astrid
A
Mentel
Thomas F
TF
D000042:Absorption; D000081008:Bicyclic Monoterpenes; D007700:Kinetics; D013058:Mass Spectrometry; D039821:Monoterpenes / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D011522:Protons; D013696:Temperature; D014329:Tropical Climate; D014466:Ultraviolet Rays
D000081008:Bicyclic Monoterpenes; D039821:Monoterpenes; D011522:Protons; D010126:Ozone; C005451:alpha-pinene