Slice imaging of the photodissociation of acetaldehyde at 248 nm. Evidence of a roaming mechanism.
The photodissociation of acetaldehyde in the molecular channel yielding CO and CH(4) at 248 nm has been studied, probing different rotational states of the CO(nu = 0) fragment by slice ion imaging using a 2+1 REMPI scheme at around 230 nm. From the slice images, clear evidence of the co-existence of two different mechanisms has been obtained. One of the mechanisms is consistent with the well-studied conventional transition state in which CO products appear rotationally excited, and the second is consistent with a roaming mechanism. This roaming mechanism is characterized by a low rotational energy disposal into the CO fragment as well as by a very low kinetic energy release, corresponding to a high internal energy in the CH(4) counter-fragment.
Rubio-Lago
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Institute of Electronic Structure and Laser, Foundation for Research and Technology--Hellas, P.O. Box 1527, 711 10, Heraklion-Crete, Greece.
Amaral
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GA
Arregui
A
A
Izquierdo
J G
JG
Wang
F
F
Zaouris
D
D
Kitsopoulos
T N
TN
Bañares
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