Argon matrix infrared spectra and vibrational analysis of the hydroperoxyl and deuteroperoxyl free radicals

Abstract

Matrix reactions of H and D atoms from a microwave discharge source with oxygen molecules diluted in argon have produced significantly higher yields of HO2 and DO2 than the previous photolysis methods. Oxygen isotopic enrichment confirmed the previous vibrational assignments to HO2; significantly greater concentrations of DO2 allowed observation of the weak 0–0 mode at 1123 cm−1. Normal coordinate calculations using HO2 and DO2 oxygen isotopic frequencies gave excellent agreement with the observed data. The bonding in HO2 is suggested to be largely covalent, in contrast to the ionic species Li+O2−.