Kinetics of the reaction between ethylperoxy radicals and nitric oxide

The kinetics of the C2H5O2 + NO --> C2H5O + NO2 reaction is examined by two real-time techniques. NO consumption and NO2 formation are measured using transient diode laser absorption, whereas ethylperoxy loss and ethylnitrite formation are monitored by time-resolved UV spectroscopy. Simultaneous fits of the NO and NO2 concentration versus time profiles yield rate constants consistent with the results of the C2H5O2 and C2H5ONO measurements. The combined data yield a rate constant of k(5) = (3.1(-1.0)(+1.5)) x 10-12(e(330+/-110)/T) cm(3) s(-1) over the 220-355 K temperature range. The small negative temperature dependence is consistent with the accepted mechanism of the reaction proceeding through a C2H5O2NO adduct.