A Study of the kinetics of the Reactions of Ethyl Radicals with O2, Cl2, and Cl

Article abstract of DOI:10.1021/j100347a044

The yield of C2H4 formed during the reaction of C2H5 with O2 has been determined at 298 K for total pressures from 6.5 to 650 Torr.Ethyl radicals were formed by pulse laser photolysis of Cl2 in mixtures of C2H6, Cl2, O2, and, in selected cases, either He or N2 diluent.Gas chromatographic analysis of the reactant and product concentrations showed that the C2H4 yield depends inversly on total pressure over the range measured, and at 650 Torr, <0.2percent of the ethane consumed forms C2H4.The ratio K₄/k₃=1.75(+/-0.35), C2H5+O2<*>C2H5O2(3) and C2H5+Cl2<*> C2H5Cl+Cl(4),was determined from the C2H5Cl yield at pressures between 50 and 650 Torr.Based on the established high-pressure rate constant for reaction 3(=4.4E-12 cm³/(molecule*s), the rate constant for reaction 4 was determined to be k₄=7.7(+/-1.6)E-12 cm³/(molecule*s).The yield of C2H4 incresed with inceasing laser power and initial Cl2 density.This effect was ascribed to the reaction C2H5+Cl<*>C2H4+HCl(5), and the rate constant for this reaction 3 was deduced from a computer simulation of the C2H4yield as a function of laser power (k₅=2.4(+/-1.2)E-10 cm³/(molecule*s)).