Reactive scattering of O(3P) atoms with alkyl and allyl iodide molecules

Abstract Differential cross sections have been measured for the reactions of O( 3 P) atoms with C 2 H 5 I, (CH 3 ) 2 CHI, (CH 3 ) 3 CI and C 3 H 5 I molecules at an initial translational energy E ≈ 36 kJ mol −1 using a supersonic beam of O atoms seeded in He buffer gas. The product angular distribution for O+C 2 H 5 I shows mild peaking in the forward and backward direction with slightly favours the backward direction, and a product translational energy distribution in accord with the predictions of phase space theory. The propensity toward backward scattering and the fraction of the total available energy disposed into product translation both increase progressively along the series of reactions. This trend is attributed to reaction at small impact parameters b ⩽2.5 A over a weakly attractive triplet potential energy surface, which splits into 3 A′ and 3 A″ Renner—Teller components in bent OIR configurations.