title: Communication: Spectroscopic observation of the O-bonded T-shaped isomer of the CO-CO2 dimer and two of its intermolecular frequencies.
abstract: Infrared spectra in the carbon monoxide CO stretch region (≈2150 cm(-1)) are assigned to the previously unobserved O-bonded form of the CO2-CO dimer ("isomer 2"), which has a planar T-shaped structure like that of the previously observed C-bonded form ("isomer 1"), but with the CO rotated by 180°. The effective center of mass intermolecular distances are 3.58 Å for isomer 2 as compared to 3.91 Å for isomer 1. In addition to the fundamental band, two combination bands are observed for isomer 2, yielding values for two intermolecular vibrational modes: 14.19 cm(-1) for the in-plane CO bend and 22.68 cm(-1) for the out-of-plane bend.
authors.affiliation: Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Sheybani-Deloui
authors.affiliation: Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada.
authors.forename: A J
authors.initials: AJ
authors.lastname: Barclay
authors.affiliation: Natural Resources Canada, CanmetENERGY, 1 Oil Patch Drive, Suite A202, Devon, Alberta T9G 1A8, Canada.
authors.forename: K H
authors.initials: KH
authors.lastname: Michaelian
authors.affiliation: National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada.
authors.forename: A R W
authors.initials: AR
authors.lastname: McKellar
authors.affiliation: Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Moazzen-Ahmadi