PULSE-RADIOLYSIS STUDY OF REACTIONS OF ALKYL AND ALKYLPEROXY RADICALSORIGINATING FROM METHYL TERT-BUTYL ETHER IN THE GAS-PHASE

UV spectra and kinetics for the reactions of alkyl and alkylperoxy rad icals from methyl tert-butyl ether (MTBE) were studied in 1 atm of SF6 by the pulse radiolysis-UV absorption technique. UV spectra for the r adical mixtures were quantified from 215 to 340 nm. At 240 nm, sigma(R ) = (2.6 +/- 0.4) X 10(-18) cm(2) molecule(-1) and sigma(RO2) = (4.1 /- 0.6) X 10(-18) cm(2) molecule(-1) (base e). The rate constant for t he self-reaction of the alkyl radicals is (2.5 +/- 1.1) X 10(-11) cm(3 ) molecule(-1) s(-1). The rate constants for reaction of the alkyl rad icals with molecular oxygen and the alkylperoxy radicals with NO and N O2 are (9.1 +/- 1.5) X 10(-13), (4.3 +/- 1.6) X 10(-12) and (1.2 +/- 0 .3) X 10(-11) cm(3) molecule(-1) s(-1), respectively. The rate constan ts given above refer to reaction at the tert-butyl side of the molecul e.