Investigation of the cross-reaction mechanism of C6H5F-HNO2 aqueous solution irradiated at 355 nm by transient absorbance spectrum technique

The transient absorption spectrum technique was employed to investigate the cross-reaction mechanism of C₆H₅F-HNO₂ aqueous solution irradiated at 355 nm. The characteristic and the kinetic parameters of transient species were also detected. Hydroxyl radical derived from the photolysis of HNO₂ was added to monofluorobenzene with a second-order rate constant of (5.83±0.17)×10⁹ L·mol⁻¹·s⁻¹ to form an adduct, C₆H₅F⋯OH, which was able to react with HNO₂ as the main reaction pathway with a rate constant of (8.3±0.1)×10⁷ L·mol⁻¹·s⁻¹. The C₆F₆⋯OH adduct can also be decayed by elimination of H₂O to yield monofluorophenyl radical C₆H₄F·. By GC-MS technique, the final products were identified to be monofluorophenol, nitro-monofluorobenzene, nitro-monofluorophenol and para-fluorobiphenyl. Supported by the National Natural Science Foundation of China (Grant No. 20377009)