Kinetics and mechanism of HO2 and DO2 disproportionations

摘要: The HO/sub 2/ + and DO/sub reactions in the gas phase have been studied by flash photolysis/UV absorption technique. Rate constants were measured at pressures between 100 700 torr of Ar N/sub temperatures 230 420 K, with up to 10 added water vapor. overall disproportionation rate constant can be expressed as sum pressure-independent pressure-dependent terms. experimental uncertainty k/sub 1/ 2/, including systematic errors, is 25% (one standard deviation). enhancement presence vapor was over temperature range 250-298 K found contribute a multiplicative term (1 1.4 x 10/sup -21/ exp(2200/T)(H/sub 2/O)) expressions. mechanism reaction investigated two-channel RRKM model which suggested that binding energy 4/H intermediate lies 12-20 kcal mol/sup -1/ relative reactants. 35 references, 8 figures, 7 tables.