Photoionization of the primary photoproducts of A((2)Pi)-excited ClO

Abstract

Photoionization of the primary photofragments of chlorine monoxide (ClO) is reported. ClO is photolyzed in the X((2)Pi)-->A((2)Pi)-regime, yielding Cl(P-2) and O(P-3,D-1). The primary photolysis products, as well as the not photolyzed ClO, are subsequently probed by monochromatic, time-correlated vacuum-ultraviolet radiation from a laser produced plasma source. Autoionization is used for state-specific detection of the atomic photolysis products. The formation of O(P-3) is exclusively observed above approximate to264 nm. The threshold of O(D-1) from A((2)Pi(3/2))-excited ClO is found at 263.71+/-0.01 nm. The shape of the O(D-1) yield near this threshold is discussed in terms of the rotational energy distribution and a rotational barrier of A((2)Pi(3/2))-excited ClO. Direct (nonresonant) one-photon-ionization is used to establish the absolute photoionization cross sections of ClO(X((2)Pi)), Cl(P-2), and O(D-1) near 15 eV. Additional experiments on the UV-photolysis of Cl-2, yielding Cl(P-2), are consistent with the results on ClO. The present work is compared to earlier experimental and theoretical studies. (C) 2002 American Institute of Physics.