Vibrational energy distribution in HF formed by elimination from activated CH3CF3 and CH2CF2

Abstract

The combination–elimination reaction CH3 + CF3 → CH3CF3† → CH2CF2 + HF has been studied in a fast-flow system. Infrared chemiluminescence arising from the HF product has been observed from vibrational levels v = 1–4, and relative rate constants, k(v), have been obtained for HF formation in these levels. A study has also been made of the reaction CH2CF2 + Hg*(63P1) → CHCF + HF + Hg(61S0), which has been found to produce vibrationally-excited HF. Relative rate constants k(v) for vibrational levels v = 1–4 have been obtained. It appears that channelling of the potential energy into HF vibration, in the course of the elimination step, is more efficient in the first than in the second of these reactions. In the second reaction HF is eliminated with considerable rotational excitation.