			10min:

TIME-RESOLVED FTIR EMISSION SPECTROSCOPY OF THE

₁ CH STRETCH MODE OF THE KETENYL (HCCO) RADICAL .

M. WILHELM, W. MCNAVAGE, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104; H. L. DAI, Department of Chemistry, Temple University, Philadelphia, PA 19122.

The ₁ CH stretch, a previously uncharacterized mode of the ketenyl (HCCO) radical, was detected at 3230cm^-1 through time-resolved Fourier transform infrared emission spectroscopy. Ro-vibrationally excited ketenyl and ethyl (CH₂CH₃) radicals were generated, with near unit quantum efficiency, via the 193 nm photodissociation of ethyl ethynyl ether .

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HCC-O- CH₂CH₃ + h (193 nm) rightarrow HCCO + CH₂CH₃

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IR emission from the photoproducts was detected with both temporal and frequency resolution. Spectral assignments were made based upon comparison with theoretical calculations as well as 2D correlation analysis.