title: Laser-induced fluorescence of isobutoxy in competition with ground state decomposition.
abstract: Spectroscopic detection is an important method to monitor alkoxy radicals in atmospheric photochemistry studies. In this work, we report the first observation of the laser-induced fluorescence (LIF) spectra of isobutoxy, 2-methyl-1-butoxy, and 3-methyl-1-butoxy in supersonic jet-cooled condition. Ground state unimolecular decomposition and isomerization as well as excited state relaxation dynamics of isobutoxy were discussed in combination with the theoretical calculations. Analysis of the experimental and theoretical results showed that methyl substitution on the β carbon of the alkoxy radicals changed the LIF spectra of alkoxy radicals significantly. The competition between the ground state reactions and the photoexcitation process depended strongly on the radical structure and hence affected the involvement of alkoxy radicals in the photochemical reactions in the upper troposphere. This study will help to understand the dynamic role of alkoxy radicals in the atmosphere.
authors.affiliation: College of Chemistry, Beijing Normal University , Beijing, 100875, P. R. China.
authors.forename: Gaiting
authors.initials: G
authors.lastname: Liang
authors.forename: Chengxuan
authors.initials: C
authors.lastname: Liu
authors.forename: Haiyan
authors.initials: H
authors.lastname: Hao
authors.forename: Lily
authors.initials: L
authors.lastname: Zu
authors.forename: Weihai
authors.initials: W
authors.lastname: Fang