REACTION BETWEEN HO2 AND CLO - PRODUCT FORMATION BETWEEN 2110 AND 300K

The products of the gas-phase reaction between HO2 and ClO have been m easured by matrix-isolation/FTIR spectroscopy at a total pressure of 7 00 Torr and at 210, 240, 270, and 300 K. HOCl was detected as the domi nant product, accounting for greater than or equal to 95% of reaction at all temperatures, showing that HO2 + ClO --> HOCl + O-2 is the majo r reaction pathway at high pressures and low temperatures. Evidence wa s found for ozone formation in this reaction at low temperatures, impl ying the presence of a second, minor (less than or equal to 5%) reacti on channel: HO2 + ClO --> HCl + O-3. NO evidence for other product cha nnels was obtained, precluding the formation of long-lived isomers of HClO3. The atmospheric implications of a second channel in which O-3 a nd HCl are products are discussed.