Infrared diode laser spectroscopy of the. nu. sub 3 fundamental of the CD sub 3 radical

Journal Article · Fri Jun 15 04:00:00 EDT 1990 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.458242· OSTI ID:6971995

Fawzy, W M; Sears, T J ^[1]; Davies, P B ^[2]

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1. Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973 (USA)
2. Department of Chemistry, University of Cambridge, Cambridge, CB2 1 EP, (United Kingdom)

The infrared absorption spectrum of the {nu}{sub 3} fundamental band of the CD{sub 3} radical has been detected by diode laser absorption spectroscopy. The CD{sub 3} radical was produced by excimer laser photolysis of CD{sub 3}I at 248 nm or (CD{sub 3}){sub 2}CO at 193 nm. Molecular parameters of the {ital v}{sub 3}=1 vibrational state were determined from a least-squares fit to 62 rotation--vibration transitions. In this fit, molecular parameters describing the ground state were constrained to those obtained from previous spectroscopic studies of the {nu}{sub 2} parallel IR band (J. M. Frye, T. J. Sears, and D. Leitner, J. Chem. Phys. {bold 88}, 5300 (1988)). The molecular parameters determined in the present work are the band origin {nu}{sub 0}=2381.088 60(84), {ital B}{prime}=4.758 737(40), {ital C}{prime}=2.373 297(34), ({zeta}{ital C}){sub 3}=0.476 278(72), {ital q}{sub 3}=0.003 76(59), {ital D}{sup {prime}}{sub {ital N}} =0.000 187 9(5), {ital D}{sub {ital NK}} ={minus}0.000 341 0(12), {ital D}{sup {prime}}{sub {ital K}} =0.000 143 7(8), {eta}{sub {ital N}} ={minus}0.000 005 5(36), {eta}{sup {prime}}{sub {ital K}} =0.000 060(35), and {ital q}{sub {ital N}} =0.000 063(17), all in cm{sup {minus}1} with one standard deviation in parentheses. The derived molecular parameters were compared with those for the CH{sub 3} radical {ital v}{sub 3}=1 level determined previously (T. Amano, P. Bernath, C. Yamada, Y. Endo, and E. Hirota, J. Chem. Phys. {bold 77}, 5284 (1982)). The molecular parameters of the {ital v}{sub 3}=1 state of the CD{sub 3} and CH{sub 3} radicals follow the expected isotopic relationships. We have also found that the determined molecular parameters reasonably satisfy the approximate planarity relationships (J. K. G. Watson, J. Mol. Spectrsoc. {bold 65}, 123 (1977)) and the sign of the {ital l}-type doubling constant is consistent with a planar equilibrium structure.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6971995
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 92:12; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

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