Kinetics and mechanisms of the reactions of CH with CH₄, C₂H₆ and n-C₄H₁₀

The reactions of CH(X ²II) with several saturated hydrocarbons were studied over a broad range of temperature. CH radicals were generated by multiphoton dissociation of CHBr₃ using 266 nm radiation and detected by their laser-induced fluorescence at 429.8 nm. All reactions studied here had rate constants that decreased with increasing temperature. The Arrhenius expressions for the rate constants obtained at 100 Torr total pressure were k₄ = 5.0 ± 0.5 × 10^-11 20 exp(200=31)/T), k₃₁T]kc2H6 = (1.8 ± 0.2) × 10^-10 exp[(132 ± 30)/T] and k_[ = (4.4 ± 0.8) × 10^-10 exp[(2[ ± 60)/T] cm^[ molecule^-1 s^[ 2 in the temperature ranges 167-652, 162-650 and 257-653 K, respectively. The rate constant for the reaction of CH-CH_[ was found to be independent of total pressure between 25 and 200 Torr.