RATE COEFFICIENTS FOR REACTIONS OF NO3 WITH A FEW OLEFINS AND OXYGENATED OLEFINS

The rate coefficients for the reactions of NO3 with 2-methyl-3-bulene- 2-ol (methyl butenol, MBO, k(1)), 1-butene (k(2)), trans-2-butene (k(3 )), methacrolein (MACR, k(4)), and methyl vinyl ketone (MVK, k(5)) wer e measured directly using a flow tube coupled to a diode laser absorpt ion system where NO3 was measured. The measured values of the rate coe fficients are k(1) = 4.6 x 10(-14) exp(-400/T) cm(3) molecule(-1) s(-1 ), k(2) = 5.2 x 10(-13) exp(-1070/T) cm(3) molecule(-1) s(-1), k(3)(29 8 K) = (4.06 +/- 0.36) x 10(-13) cm(3) molecule(-1) s(-1), k(4)(298 K) less than or equal to 8 x 10(-15) cm(3) molecule(-1) s(-1), and k(5)( 298 K) less than or equal to 1.2 x 10(-16) cm(3) molecule(-1) s(-1). T he observed reactivity trends are correlated in terms of the presence of electron-withdrawing substituents, which reduces the reactivity of alkenes toward NO3 addition to the double bond. The contribution of NO 3 reactions to determining the tropospheric lifetimes of these compoun ds are also calculated.