This study reports measurements of the thermal dissociation of 1,1-difluoroethane in the shock tube. The experiments employ laser schlieren measurements of rate for the dominant HF elimination using 10% 1,1-difluoroethane in Kr over 1500–2000 K and 43 < P < 424 torr. The product vinyl then dissociates affecting the late density gradient. We include a laser schlieren study (1717–2332 K, 75 < P < 482 torr in 10% and 4% vinyl fluoride in Kr) of this dissociation. This latter work also includes a set of experiments using shock-tube time-of-flight mass-spectrometry (4% vinyl fluoride in neon, 1500–1980 K, 500 < P < 1300 torr), which confirm the theoretical expectation that the only reaction in vinyl fluoride is HF elimination. The relaxation experiments (1–20% C₂H₃F in Kr, 415–1975 K, 5 < P < 50 torr, and 2% and 5% C₂H₄F₂ in Kr, 700–1350 K, 6 < P < 22 torr) exhibit very rapid relaxation, and incubation delays should be negligible in dissociation. A RRKM model of dissociation in 1,1-difluoroethane based on a G3B3 calculation of barrier and other properties fits the experiments but requires a very large <ΔE>_down of 1600cm^-1 . Dissociation of vinyl fluoride has two parallel HF eliminations both three-center and four-center with nearly equal barriers. An RRKM fit to the observed falloff again requires an unusually large <ΔE>down and the experiments actually support a slightly reduced barrier.

Both 1,3,5-triazine and pyrazine relax extremely rapidly with energy transfer in a few collisions, any incubation delay can be confidently discounted in dissociation. 1,3,5-triazine dissociation experiments show fall-off with a clear pressure dependence. The three body product dissociation mechanism models this dissociation perfectly. Experimental data agree well with an RRKM calculation using a <ΔE>_down of 1200cm^-1 and a barrier E₀ = 84.66 kcal/mol. Dyakov et al. suggested lower barrier of E₀ = 81 kcal/mole. The new RRKM calculation using this barrier seems a better fit to the experiments. The falloff is now fit well with a <ΔE>_down of the more usual form 126(T/298) ^0-9 cm^-1.