Air broadening coefficients for the ν3 band of hydroperoxyl radicals.

Using mid-infrared laser absorption spectroscopy, we investigated the room-temperature pressure broadening coefficients for hydroperoxyl radicals (HO 2 ) in nitrogen and oxygen over the 1060.0–1065.5 cm −1 range of the ν 3 band. The HO 2 radicals were produced by flash photolysis of a chlorine/1,4-cyclohexadiene/oxygen mixture. The 20 measured absorption profiles were analyzed with Voigt functions. Air broadening coefficients were estimated from the nitrogen- and oxygen-broadening results and compared with previous results. We discuss the dependence of air broadening on rotational states. [ABSTRACT FROM AUTHOR]