DETERMINATION OF THE RATE-CONSTANT AND OF PRODUCT BRANCHING RATIOS INTHE REACTION OF CH3O2 WITH OCL BETWEEN 233-K AND 300-K

The reaction CH3O2 + OCl-->prod (1) has been investigated in the tempe rature range 233-300 K using discharge flow mass-spectrometric techniq ue. A rate constant k(1), (300 K) = (2.5 +/- 0.3) 10(-12) cm(3) molecu le(-1) s(-1) has been obtained observing the pseudo-first-order decay of CH3O2 radicals. The observed temperature dependence is described by k(l) (233-300 K) = (2.0 +/- 0.1) 10(-12) exp ((80 +/- 50)/T) cm(3) mo lecule(-1) s(-1). The reaction channel (1a) CH3O2+OCl-->CH3OCl+O-2, le ading to CH3OCl formation was identified and found to be negatively te mperature dependent with k(1a) (233-300 K) = (1.5 +/- 0.3) 10(-14) exp ((920 +/- 200)/ T) cm(3) molecule(-1) s(-1). It is shown that HCHO an d HOCl result from the secondary reaction of OCl with CH3O.