The recent demonstration of a discharge-driven oxygen-iodine laser has generated renewed interest in the kinetics of iodine interacting with electronically excited O-2 and atomic O. Kinetic measurements that are of relevance to the laser have been carried out using 193 nm pulsed laser photolysis of N2O/I-2/CO2 mixtures. Singlet oxygen was generated in this system by the reaction O(D-1) + N2O -> O-2(a(1)Delta(g), X-3 Sigma(-)(g)) + N-2. The fraction of electronically excited O-2 produced by this channel was shown to be > 0.9. The secondary photochemistry of the N2O/I-2/CO2 system was characterized by monitoring the time histories of I(P-2(1/2)), I-2, IO, and O-2(a). Kinetic modeling of these data was used to determine the rate constant for the deactivation of I(P-2(1/2)) by O(P-3) (k = (1.2 +/- 0.1) x 10(-11) cm(3) s(-1)). Quenching of I(P-2(1/2)) by O(P-3) is suppressed in the discharge-driven laser by using NO2 to scavenge the O atoms. The reaction O(P-3) + NO2 -> O-2 + NO is sufficiently exothermic for the production of O-2(a), and it has been speculated that this channel may be significant in the laser excitation kinetics. Photolysis of NO2 was used to probe this reaction. O-2(a) was not detected, and an upper bound of < 0.1 for its production in the reaction of O(P-3) or O(D-1) with NO2 was established.