Vibrationally excited carbon dioxide produced by infrared multiphoton pyrolysis

Vibrationally excited CO/sub 2/ has been observed in the infrared multiphoton pyrolysis (IRMP) of some organic molecules. The pyrolysis was induced by a high-power, pulsed CO/sub 2/ TEA laser. The vibrational excitation of CO/sub 2/ was investigated by time-delayed, intracavity probing with a weak flash photolysis CO/sub 2/ laser. The molecules 2-oxetanone (..beta..-propiolactone), 3-butenoic acid (vinylacetic acid), and 2-oxopropanoic acid (pyruvic acid) were all shown to produce vibrationally excited CO/sub 2/ as one of the photofragments. The excitation involved the symmetric stretching mode, as well as the asymmetric stretching mode, of CO/sub 2/. The results provide information about the structural dynamics of each reaction as well as the geometry of the transition states. 7 references, 5 figures.