title: The overall reaction process of ozone with methacrolein and isoprene in the condensed phase.
abstract: The reaction of isoprene and methacrolein with ozone was investigated at different stages in the condensed phase at temperatures from 15 to 265 K by IR spectroscopy. The results revealed the following overall reaction process: the generation of primary ozonide (POZ), then its decomposition, and finally conversion into secondary ozonide (SOZ), which supported the Criegee mechanism. In the POZ and SOZ of isoprene, ozone cyclo-added preferentially to the double-bond that is not substituted by the methyl group. For methacrolein, the mainly detected SOZ is claimed to be MACSII formed by recombination of the intermediate CH(2)OO radical with aldehyde carbonyl of methylglyoxal in stead of the ketone carbonyl group. Theoretical calculations were performed at the B3LYP//MP2/6-311++G (2d, 2p) level to analyze the resulting spectrum. The good agreement between the calculated infrared spectra of POZ and SOZ and the experimental spectra supports the above-described findings.
authors.affiliation: State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Science, Beijing 100012, China.
authors.forename: Jian-guo
authors.initials: JG
authors.lastname: Deng
authors.forename: Jian-hua
authors.initials: JH
authors.lastname: Chen
authors.forename: Chun-mei
authors.initials: CM
authors.lastname: Geng
authors.forename: Hong-jie
authors.initials: HJ
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Zhi-peng
authors.initials: ZP
authors.lastname: Bai
authors.forename: Yi-Sheng
authors.initials: YS
authors.lastname: Xu
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives* / Q000737:chemistry; D002070:Butadienes / Q000737:chemistry*; D045782:Hemiterpenes / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D010420:Pentanes / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D002070:Butadienes; D045782:Hemiterpenes; D010420:Pentanes; C005059:isoprene; D010126:Ozone; D000171:Acrolein; C039175:methacrylaldehyde