Gas-phase absorption cross sections of 2-nitrobenzaldehyde and benzaldehyde in the 285–400 nm region, and photolysis of 2-nitrobenzaldehyde vapor at 308 and 351 nm

We have measured the gas-phase absorption cross sections of 2-nitrobenzaldehyde and benzaldehyde in the 285–400 nm region by using cavity ring-down spectroscopy (CRD). Absorption cross sections of 2-nitrobenzaldehyde vapor at 290 and 400 nm are 10.7-fold and 5.5-fold lower than 2-nitrobenzaldehyde aqueous-phase cross section values. The HCO and the NO2 product channels, after 308 and 351 nm photolysis of 2-nitrobenzaldehyde vapor, were examined. Neither HCO nor NO2 was detected. Upper limits for the HCO and NO2 quantum yields are ⩽2.2% and ⩽6.4% at 308 nm, respectively. Preliminary end-product study indicates that 2-nitrobenzaldehyde photodissociates at 308 nm but not at 351 nm.