title: Conformational analysis of ethyl-substituted Criegee intermediate by FTMW spectroscopy.
abstract: Ethyl-substituted Criegee intermediate, C2H5CHOO, has been generated in the discharged plasma of a 1,1-diiodopropane/O2gas mixture and spectroscopically characterized by Fourier transform microwave spectroscopy in a pulsed supersonic jet. The comparison between the experimental rotational constants and those calculated ab initio unambiguously confirms the identification of three conformers, providing the definitive probe for their molecular structures. Some of the observed pure rotational transitions show small splittings corresponding to the A/E components due to the threefold methyl internal rotation, which made it possible to determine the barrier heights of the hindered methyl rotation. The conformational abundances as well as the non observation of a plausible fourth conformer have been rationalized in terms of interconversion processes between conformers and interactions between the terminal oxygen and the protons of the ethyl moiety.
authors.affiliation: Department of Applied Chemistry, National Chiao Tung University, Science Building II, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan.
authors.forename: Carlos
authors.initials: C
authors.lastname: Cabezas
authors.affiliation: Institut des Sciences Chimiques de Rennes, École Nationale Supérieure de Chimie de Rennes, UMR CNRS 6226, 11 Allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Guillemin
authors.affiliation: Department of Applied Chemistry, National Chiao Tung University, Science Building II, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan.
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Endo