L. Goldfarb et al., PHOTODISSOCIATION OF CLONO2 .1. ATOMIC RESONANCE FLUORESCENCE MEASUREMENTS OF PRODUCT QUANTUM YIELDS, The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory, 101(36), 1997, pp. 6658-6666
The quantum yields for the production of Cl, O, and ClO in the photoly
sis of ClONO2, measured by detecting Cl and O atoms by atomic resonanc
e fluorescence, are reported. The resonance fluorescence signals were
calibrated by generating known concentrations of Cl and O atoms from t
he photolysis of Cl-2, HCl, O-3, or N2O. The quantum yields for Ci in
the 193.2, 222.0, 248.25, and 308.15 nm photolysis of ClONO2 were 0.53
+/- 0.10, 0.46 +/- 0.10, 0.41 +/- 0.13, and 0.64 +/- 0.20, respective
ly. The yields for O atoms at these wavelengths were, respectively, 0.
37 +/- 0.08, 0.17 +/- 0.05, <0.10, and <0.05. The quoted uncertainties
are 2 sigma precision of the measurements. ClO radical was converted
to Cl via addition of NO and its signal compared to the Cl atom signal
produced by photolysis of ClONO2. The obtained quantum yields for ClO
were 0.29 +/- 0.20, 0.64 +/- 0.20, 0.39 +/- 0.19, and 0.37 +/- 0.19,
at 193.2, 222.0, 248.25, and 308.15 nm, respectively. It appears that
Cl + NO3 and ClO + NO2 are the major products in the photodissociation
of ClONO2, except at 193 nm. The measured quantum yields were found t
o be independent of pressure (40-100 Ton) and bath gas (He and N-2). O
ur results are compared with those from previous measurements.