ARRHENIUS PARAMETERS FOR THE REACTION OF THE NITRATE RADICAL WITH 1,1-DICHLOROETHENE AND (E)-1,2-DICHLOROETHENE

The kinetics of the reactions of the nitrate radical, NO3, with 1,1-di chloroethene and (E)-1,2-dichloroethene have been measured using the d ischarge-flow technique coupled to detection of NO3 by optical absorpt ion. The values obtained for the rate coefficients at room temperature are (1.2 +/- 0.3) x 10(-15) and (1.2 +/- 0.5) x 10(-16) cm(3) molecul e(-1) s(-1) (95% confidence with 15% systematic errors included) and t he derived Arrhenius expressions are k(2)(T) = (4.7 +/- 2.4) x 10(-13) exp[-(1800 +/- 240)/T] and k(3)(T) = (4.5 +/- 0.5) x 10(-13) exp[-(24 00 +/- 40)/T] cm(3) molecule(-1) s(-1) (errors quoted at 1 sigma). Com parison of the results with those of previous studies indicates that C l-atom elimination is not important for either reaction. The dependenc e of the kinetic parameters on the molecular structure of the dichloro ethenes is discussed.