Infrared laser transient absorption spectroscopy of the ethyl radical

Journal Article · Mon Jan 01 04:00:00 EST 1996 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.470803· OSTI ID:253455

Sears, T J ^[1]; Johnson, P M ^[2]; Jin, P ^[1]; Oatis, S ^[3]

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1. Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)
2. Department of Chemistry, State University of New York, Stony Brook, New York 11974 (United States)
3. Department of Chemistry, Long Island University, Southampton, New York 11968 (United States)

The observation and analysis of the high resolution spectrum of the CH{sub 2} rocking fundamental of the ethyl radical, C{sub 2}H{sub 5}, at wavelengths close to 18.9 {mu}m is reported. The band origin is found to be at 528.1 cm{sup -1}. The spectrum shows evidence for a very low barrier to internal rotation, or torsion, in this species. A simple model Hamiltonian, based on an assumed structure with {ital G}{sub 12} symmetry, qualitatively reproduces the observations and implies a torsional barrier of approximately 20 cm{sup -1} in both the zero point and excited vibrational states. The Hamiltonian cannot reproduce the observations to the level of the experimental accuracy and the importance of several neglected terms is tested and discussed. The observed torsional splittings imply that, within the confines of the model, the {ital a}-inertial and internal rotation axes in the molecule are coincident to within 1{degree}. In addition to their intrinsic interest, the spectra will be useful for future state resolved studies of the kinetics of chemical reactions involving the radical. {copyright} {ital 1996 American Institute of Physics.}

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016
• OSTI ID: 253455
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 3 Vol. 104; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ABSORPTION SPECTRA
ETHYL RADICALS
EXCITED STATES
HAMILTONIANS
HIGH-RESOLUTION METHODS
INFRARED SPECTRA
TORSION
VIBRATIONAL STATES