Abstract
The ultraviolet photodissociation dynamics of C/sub 4/H/sub 2/N/sub 2/ at 193 nm has been studied under both low and high laser fluence conditions. At low laser fluences, LIF studies indicate that CN(X) radicals are produced in the nu'' = 0 and nu'' = 1 vibrational levels, with a Boltzmann-like rotational distribution characterized by a T/sub rot/ of 1330 +/- 10 and 1340 +/- 10 K, respectively. When the laser fluence is increased, emissions from the CN radical in the A/sup 2/II, B/sup 2/..sigma../sup +/, E/sup 2/..sigma.., and F/sup 2/..delta.. states are also seen. These emissions are explained in terms of a sequential absorption mechanism which produces doubly excited C/sub 4/H/sub 2/N/sub 2/. The doubly excited molecule subsequently dissociates to produce vibrationally excited CN(A/sup 2/II) and CN(B/sup 2/..sigma../sup +/) radicals. The E(/sup 2/..sigma..) and F(/sup 2/..delta..) states of the CN are produced by the absorption of a 193-nm photon by CN(A) radicals. The gas-phase room temperature UV absorption spectrum between 190 and 300 nm has also been measured.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have