Ca. Longfellow et Yt. Lee, METHANE LOSS IN THE INFRARED MULTIPHOTON DISSOCIATION OF ACETIC-ACID, Journal of physical chemistry, 99(42), 1995, pp. 15532-15537
The infrared multiphoton dissociation (IRMPD) of acetic acid was studi
ed by photofragment translational spectroscopy. Carbon dioxide and met
hane were observed for the first time as products from dissociation un
der collisionless conditions. The product translational energy distrib
ution for this channel peaks well away from zero, which supports a fou
r-center transition state. A previously observed channel, resulting in
the formation of ketene and water, was verified. The average translat
ional energy release for the former channel was measured to be 26.4 kc
al/mol, and a value of 18.6 +/- 2 kcal/mol was obtained for the dehydr
ation channel. With a laser fluence of 12 J/cm(2), decarboxylation acc
ounts for roughly 35% of the total dissociation yield.