Laser-induced-fluorescence spectroscopy of jet-cooled C sub 3

Journal Article · Sun Oct 15 04:00:00 EDT 1989 · Journal of Chemical Physics; (USA)

DOI:https://doi.org/10.1063/1.456791· OSTI ID:5487016

Rohlfing, E A ^[1]

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1. Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551 (US)

We present a spectroscopic study of jet-cooled C{sub 3} in which laser-induced-fluorescence (LIF) excitation spectra and dispersed-fluorescence (DF) spectra are taken for a new, vibronically induced band system ({sup 1}{Pi}{sub {ital g}} and/or {sup 1}{Delta}{sub {ital u}})--{ital {tilde X}} {sup 1}{Sigma}{sup +}{sub {ital g}} in the ultraviolet. In addition, DF spectra are taken for the well-known cometary band system, {ital {tilde A}} {sup 1}{Pi}{sub {ital u}}--{ital {tilde X}}{sup 1}{Sigma}{sup +}{sub {ital g}}. The DF spectra of the new system are very rich and display strong fluorescence bands in stretch--bend progressions that reach as high as 17 000 cm{sup {minus}1} in the {sup 1}{Sigma}{sup +}{sub {ital g}} ground state. The data from the DF spectra of both systems is used to assign vibrational term energies to 144 ground-state levels that cover the range: 0{le}{ital v}{sub 1}{le}8, 0{le}{ital v}{sub 2}{le}37, and 0{le}{ital v}{sub 3}{le}4. The observed level structure clearly demonstrates the highly anharmonic nature of the potential energy surface of C{sub 3} and the unusual internal dynamics that occurs upon it. These include pronounced barriers to linearity in the {ital v}{sub 3}=2 and {ital v}{sub 3}=4 states and an increase in molecular rigidity as the symmetric stretch is excited.

• OSTI ID: 5487016
• Journal Information: Journal of Chemical Physics; (USA), Journal Name: Journal of Chemical Physics; (USA) Vol. 91:8; ISSN JCPSA; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
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ABSORPTION SPECTRA
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ATMOSPHERES
CARBON
COMBUSTION PRODUCTS
COMETS
ELEMENTS
EMISSION SPECTROSCOPY
FLUORESCENCE SPECTROSCOPY
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