Møller KH, Praske E, Xu L, Crounse JD, Wennberg PO, Kjaergaard HG. Stereoselectivity in Atmospheric Autoxidation.
J Phys Chem Lett 2019;
10:6260-6266. [PMID:
31545897 DOI:
10.1021/acs.jpclett.9b01972]
[Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We show that the diastereomers of hydroxy peroxy radicals formed from OH and O2 addition to C2 and C3, respectively, of crotonaldehyde (CH3CHCHCHO) undergo gas-phase unimolecular aldehydic hydrogen shift (H-shift) chemistry with rate coefficients that differ by an order of magnitude. The stereospecificity observed here for crotonaldehyde is general and will lead to a significant diastereomeric-specific chemistry in the atmosphere. This enhancement of specific stereoisomers by stereoselective gas-phase reactions could have widespread implications given the ubiquity of chirality in nature. The H-shift rate coefficients calculated using multiconformer transition state theory (MC-TST) agree with those determined experimentally using stereoisomer-specific gas-chromatography chemical ionization mass spectroscopy (GC-CIMS) measurements.
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