title: Infrared absorption of 3-propenonyl (·CH2CHCO) radical generated upon photolysis of acryloyl chloride [CH2CHC(O)Cl] in solid para-H2.
abstract: Irradiation at 193 nm of a p-H2 matrix containing acryloyl chloride CH2CHC(O)Cl at 3.2 K yielded infrared absorption lines at 3143.6 (ν1), 3057.0 (ν2), 3048.0 (ν3), 2103.1 (ν4), 1461.0 (ν5), 1349.8 (ν6), 1223.7 (ν11+ν12 or 2ν12), 1092.8 (ν8), 918.1 (ν9), 691.0 (ν10), 624.3 (ν11), and 597.1 (ν12) cm(-1) that are assigned to the 3-propenonyl (·CH2CHCO) radical. The assignments are based on the photolytic behavior and a comparison of observed vibrational wavenumbers and infrared intensities with those predicted with the B3PW91/aug-cc-pVDZ method. The observation is consistent with a major radical formation channel CH2CHCO + Cl followed by escape of the Cl atom from the original p-H2 cage. The observation of 3-propenonyl (·CH2CHCO) radical but not 3-propenalyl (s-cis- or s-trans-CH2CHĊO) radical indicates that the former is the most stable isomer and that the barrier heights for conversion from s-cis- or s-trans-CH2CHĊO to ·CH2CHCO are small.
authors.affiliation: Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu 30010, Taiwan.
authors.forename: Prasanta
authors.initials: P
authors.lastname: Das
authors.forename: Yuan-Pern
authors.initials: YP
authors.lastname: Lee