Infrared chemiluminescence in the systems F + CH4 and F + CH2F2. The effect of secondary reaction

HF is produced vibrationally-rotationally excited in the gas phase systems F + CH4 and F + CH2F2. The nascent vibrational distributions observed by IR chemiluminescence for the primary hydrogen abstractions are N1 : N2 : N3 = 30 : 58 : 12 and 36 : 45 : 19 respectively, in fair agreement with published work. With fluorine atoms in excess we measured N1 : N2 : N3 = 24 : 67 : 9 and 42 : 39 : 20, respectively. This shows qualitative differences for the inversion N2/N1 comparing the two reactions. The discussion proposes an influence by the secondary processes: F + CH3 → HF+ + CH2 and F + CHF2 → HF+ + CF2.