Abstract
ABSTRACTPeroxy radicals can complex with water vapor. These complexes affect tropospheric chemistry. In this study, β‐HEP (hydroxyethyl peroxy radical) serves as a model system for investigating the effect of water vapor on the kinetics and product branching ratio of the self‐reaction of peroxy radicals. The self‐reaction rate coefficient was determined at 274–296 K with water vapor between 1.0 × 1015 and 2.5 × 1017 molecules cm−3 at 200 Torr total pressure by slow‐flow laser flash photolysis coupled with UV time‐resolved spectroscopy and long‐path, wavelength modulated, diode‐laser spectroscopy. The overall self‐reaction rate constant expressed as the product of both a temperature‐dependent and water vapor–dependent term is , suggesting formation of a β‐HEP‐H2O complex is responsible for the increase in the self‐reaction rate coefficient with increasing water concentration. Complex formation is supported by computational results identifying three local energy minima for the β‐HEP‐H2O complex. As the troposphere continues to get warmer and wetter, more of the peroxy radicals present will be complexed with water. Investigating the effect of water vapor on kinetics of atmospherically relevant radicals and determining the effects of these altered kinetics on tropospheric ozone concentrations is thus important.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
