DOI: 10.1002/kin.21682 ISSN:

Temperature‐dependent kinetics of the gas‐phase reactions of Cl atoms with nopinone, ketolimonene, and myrtenal

Mariam Fakih, Estelle Roth, Alexandre Tomas, Abdelkhaleq Chakir
  • Inorganic Chemistry
  • Organic Chemistry
  • Physical and Theoretical Chemistry
  • Biochemistry


In this study, the gas phase reaction of chlorine atoms with three first‐generation oxidation products of monoterpene: (myrtenal C10H14O, nopinone C9H14O, and ketolimonene C9H14O) were investigated using a relative technique method. These compounds result from the atmospheric oxidation of monoterpene compounds such as α/β – pinene and limonene. Experiments were performed at temperature range 298–353 K and atmospheric pressure in synthetic air bath gas. Cl atoms were generated by UV photolysis of dichloride (Cl2). The reaction was followed using a proton‐transfer reaction mass spectrometer (PTR‐MS) and/or Fourier‐transform infrared spectroscopy (FTIR) to monitor the concentrations of the investigated species simultaneous with several reference compounds as a function of time. The rate constants were obtained and the Arrhenius expressions (cm3 molecule−1 s−1) obtained were established over the temperature range of 298–353 K:

knopinone + Cl =  (5.0  ±  1.2) ×  10−10 exp ( − (406  ±  78) /T)

kketolimonene + Cl =  (8.88 ±  1.3) × 10−10 exp( − (246 ± 46)/T)

kmyrtenal + Cl =  (13.5 ±  6.4) × 10−10 exp( − (535 ±  153)/T)

Based on rate constants, the atmospheric lifetimes (τ) of targeted compounds with respect to reaction with chlorine atoms were estimated and expected to be less than 1 day. There results led to conclude that the reaction with chlorine atoms can be an effective tropospheric loss pathway mainly in regions presenting relatively high chlorine concentrations.

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