Flash Photochemical Study of the Reaction OH+NO+M Using Resonance Fluorescent Detection of OH

Abstract

The kinetic behavior of OH radicals was studied in the presence of a large excess of NO at 5–82 torr He. Hydroxyl radicals were produced by pulsed vacuum‐uv photolysis of H₂O and were monitored directly by a resonance fluorescence method. The rate constant for the reaction OH+NO was nonlinearly dependent on the concentration of diluent He in this pressure range. The high pressure limit of the bimolecular rate constant was determined to be ${\text{(2± 1)× 10}}^{\text{−12}}{\mathrm{cm}}^3{\mathrm{molecule}}^{\text{−1}}·{\sec }^{\text{−1}}$ at 300°K.