Atmospheric Sink of (E)-3-Hexen-1-ol, (Z)-3-Hepten-1-ol, and (Z)-3-Octen-1-ol: Rate Coefficients and Mechanisms of the OH-Radical Initiated Degradation

Environ Sci Technol. 2015 Jul 7;49(13):7717-25. doi: 10.1021/es506125c. Epub 2015 Jun 12.

Abstract

A kinetic study of the gas-phase reactions of OH radicals with three unsaturated biogenic alcohols, (E)-3-hexen-1-ol, (Z)-3-hepten-1-ol, and (Z)-3-octen-1-ol, has been performed. The rate coefficients obtained are (in units of 10(-10) cm(3) molecule(-1) s(-1)) k1 (OH + (E)-CH2(OH)CH2CH═CHCH2CH3) = (1.14 ± 0.14), k2 (OH + (Z)-CH2(OH)CH2CH═CHCH2CH2CH3) = (1.28 ± 0.23), and k3 (OH + (Z)-CH2(OH)CH2CH═CHCH2CH2CH2CH3) = (1.49 ± 0.35). In addition, a product study on the reactions of OH with (E)-3-hexen-1-ol and (Z)-3-hepten-1-ol is reported. All the experiments were performed at (298 ± 2) K and 1 atm of NOx-free air in a 1080 L photoreactor with in situ FTIR detection of organics. This work constitutes the first kinetic study of the reactions of OH radicals with (Z)-3-hepten-1-ol and (Z)-3-octen-1-ol as well as the first determination of the fate of the hydroxy alkoxy radicals formed in the title reactions. An analysis of the available rates of addition of OH and Cl to the double bond of different unsaturated alcohols at 298 K has shown that they can be related by the expression log kOH = (0.29 ± 0.04) log kCl - 10.8. The atmospheric lifetimes of the alcohols studies were estimated to be around 1 h for reaction with OH radicals. The products formed in the title reactions are mainly carbonylic compounds that can contribute to the formation of ozone and PANs-type compounds in the troposphere.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohols / chemistry
  • Atmosphere / chemistry*
  • Heptanol / analogs & derivatives*
  • Heptanol / chemistry
  • Hexanols / chemistry*
  • Hydroxyl Radical / chemistry*
  • Kinetics
  • Octanols / chemistry*
  • Structure-Activity Relationship
  • Thermodynamics

Substances

  • Alcohols
  • Hexanols
  • Octanols
  • 3-hexen-1-ol
  • Hydroxyl Radical
  • Heptanol
  • (Z)-3-hepten-1-ol
  • 1-octen-3-ol