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Title: Microwave spectroscopy of the allenyloxy radical (CH{sub 2}=CCHO)

Pure rotational spectra of the allenyloxy radical (CH{sub 2}=CCHO) were observed by Fourier transform microwave (FTMW) and FTMW-millimeter wave double-resonance spectroscopy. Molecular constants including the hyperfine interaction constants of CH{sub 2}=CCHO in the {sup 2}A{sup ″} ground electronic state were precisely determined. Ab initio calculations indicate that CH{sub 2}=CCHO has a linear C−C−C backbone with C{sub s} symmetry, where the formyl group is in the C{sub s} plane and perpendicular to the methylene group. The determined rotational constants and the inertial defect agree well with those derived from the calculations, implying that the calculated molecular structure is reasonable. The fine and hyperfine constants also agree with those derived from the calculated spin density, where the unpaired electron is located mainly on the central carbon atom. The ground state CH{sub 2}=CCHO can, thus, be described as taking the formylvinyl (CH{sub 2}=Ċ−CH=O) form rather than as the allenyloxy (CH{sub 2}=C=CH−O{sup .}) form.
Authors:
; ;  [1]
  1. Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan)
Publication Date:
OSTI Identifier:
22255247
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; DENSITY; ELECTRONS; FOURIER TRANSFORMATION; GROUND STATES; INTERACTIONS; MICROWAVE RADIATION; MOLECULAR STRUCTURE; RADICALS; SPECTRA; SPECTROSCOPY