OH radical formation from the gas-phase reaction of ozone with terminal alkenes and the relationship between structure and mechanism

Journal Article · Thu Oct 14 04:00:00 EDT 1999 · Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory

DOI:https://doi.org/10.1021/jp991995e· OSTI ID:20001146

Paulson, S E; Chung, M Y; Hasson, A S

The reactions of ozone with alkenes have been shown recently to lead to the direct production of OH radicals in quantities that vary from 7 to 100% depending on the structure of the alkene. OH radicals are the most important oxidizing species in the lower atmosphere, and the OH-alkene reaction is a large source of new OH radicals, important in urban and rural air during both day and night. Evidence for OH formation comes both from low-pressure direct measurements and from tracer experiments at high pressure. With the goal of measuring OH formation yields with good precision, a small-ratio relative rate technique was developed. This method uses small amounts of fast-reacting aromatics and aliphatic ethers to trace OH formation yields. Here, the authors report OH formation yields for a series of terminal alkenes reacting with ozone. Measured OH yields were 0.29 {+-} 0.05, 0.24 {+-} 0.05, 0.18 {+-} 0.04, and 0.10 {+-} 0.03 for 1-butene, 1-pentene, 1-hexene, and 1-octene, respectively. For the methyl-substituted terminal alkenes methyl propene and 2-methyl-1-butene, OH yields were 0.72 {+-} 0.12 and 0.67 {+-} 0.12, respectively. The results are discussed both in terms of their atmospheric implications and the relationship between structure and OH formation.

• Research Organization: Univ. of California, Los Angeles, CA (US)
• OSTI ID: 20001146
• Journal Information: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory, Journal Name: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory Journal Issue: 41 Vol. 103; ISSN 1089-5639; ISSN JPCAFH
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ALKENES
ATMOSPHERIC CHEMISTRY
HYDROXIDES
OZONE
RADICALS
SYNTHESIS