Rates of OH radical reactions. VI. Reactions with C3H6, 1-C4H8 and 1-C5H10 at 297 K

Absolute rate constants, for the reactions of hydroxyl radicals with C3H6, 1-C4H8 and 1-C5H10 at 297±2 K, have been measured in the gas phase, using the flash-photolysis resonance-absorption technique and OH from the flash-photolysis of N2O/H2 mixtures, λ≳200 nm. The rate constants in units of cm3 mol−1 s−1 were found to be: kC3H6=1.48±0.17×1013, k1-C4H8=2.01±0.15×1013, and k1-C5H10=2.39±0.23×1013. The quoted errors are the 95% confidence limits. The approximate concentration of free radicals formed in the system has been determined in separate experiments. The maximum effect of secondary reactions of these radicals on the measured rates has been discussed and assessed to be less than 10%.