N 2 O 5 photolysis products investigated by fluorescence and optoacoustic techniques

Pulsed laser photolysis of N 2 O 5 near 290 nm coupled with fluorescence detection (calibrated by NO 2 photolysis) showed that the O( 3 P) quantum yield is ≤0.1. A pulsed laser optoacoustic technique in a flow tube (ca. 6 torr of N 2 ) was tested by photolysis of NO 2 and then applied to N 2 O 5 . Nitric oxide was added to react with NO 3 free radical and the resulting increase in the optoacoustic signal confirmed the presence of NO 3 free radicals. Based on the relative optoacoustic signals observed for NO 2 and N 2 O 5 , the quantum yield for NO 3 production is 0.8 ± 0.2.