Jump to main content
Jump to site search


Site-specific hydrogen-atom elimination in photoexcited ethyl radical

Author affiliations

Abstract

The photochemistry of the ethyl radical following excitation to the 3p Rydberg state is investigated in a joint experimental and theoretical study. Velocity map images for hydrogen atoms detected from photoexcited isotopologues CH3CH2, CH3CD2 and CD3CH2 at ∼201 nm, are discussed along with high-level ab initio electronic structure calculations of potential energy curves and non-adiabatic coupling matrix elements (NACME). A novel mechanism governed by a conical intersection allowing prompt site-specific hydrogen-atom elimination is presented and discussed. For this mechanism to occur, an initial ro-vibrational excitation is allocated to the radical permitting to access this reaction pathway and thus to control the ethyl photochemistry. While hydrogen-atom elimination from cold ethyl radicals occurs through internal conversion into lower electronic states followed by slow statistical dissociation, prompt site-specific Cα elimination into CH3CH + H, occurring through a fast non-adiabatic crossing to a valence bound state followed by dissociation through a conical intersection, is accessed by means of an initial ro-vibrational energy content into the radical. The role of a particularly effective vibrational promoting mode in this prompt photochemical reaction pathway is discussed.

Graphical abstract: Site-specific hydrogen-atom elimination in photoexcited ethyl radical

Back to tab navigation

Supplementary files

Publication details

The article was received on 02 May 2019, accepted on 22 May 2019 and first published on 22 May 2019


Article type: Edge Article
DOI: 10.1039/C9SC02140J
Chem. Sci., 2019, Advance Article
  • Open access: Creative Commons BY-NC license
  •   Request permissions

    Site-specific hydrogen-atom elimination in photoexcited ethyl radical

    D. V. Chicharro, S. M. Poullain, A. Zanchet, A. Bouallagui, A. García-Vela, M. L. Senent, L. Rubio-Lago and L. Bañares, Chem. Sci., 2019, Advance Article , DOI: 10.1039/C9SC02140J

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements