Flash Photolysis and Time-Resolved Mass Spectrometry. I. Detection of the Hydroxyl Radical

Abstract

Improved techniques of flash photolysis and time‐resolved mass spectrometry have been applied for the first time to the detection of a transient, reactive free radical. The hydroxyl radical has been observed simultaneously with the formation of water in the nitrogen dioxide sensitized reaction between hydrogen and oxygen. In addition, the effect of added oxygen and total pressure upon the induction periods for hydroxyl formation is correlated with the temperature dependence of concomitant flash heating. It is concluded, in agreement with the literature, that an increase in flash intensity leads to reaction acceleration through an increased initial supply of oxygen atoms.