N2O5 photolysis products investigated by fluorescence and optoacoustic techniques

Pulsed laser photolysis of N2O5 near 290 nm coupled with fluorescence detection (calibrated by NO2 photolysis) showed that the O(3P) quantum yield is ≤0.1. A pulsed laser optoacoustic technique in a flow tube (ca. 6 torr of N2) was tested by photolysis of NO2 and then applied to N2O5. Nitric oxide was added to react with NO3 free radical and the resulting increase in the optoacoustic signal confirmed the presence of NO3 free radicals. Based on the relative optoacoustic signals observed for NO2 and N2O5, the quantum yield for NO3 production is 0.8 ± 0.2.