Very low‐pressure pyrolysis. IX. The decomposition of azoethane, azoisopropane, and 2,2′‐azoisobutane

The very low‐pressure (VLPP) technique was used to study the pyrolysis of azoethane (AE), azoisopropane (AIP), and 2,2′‐azoisobutane (AIB). The low pressure rate constants were related to the high‐pressure Arrhenius parameters by means of the RRKM theory. This procedure in itself does not yield an unambiguous set of parameters. However, thermochemical and kinetic arguments are given which support the following values of log k∞ for the pyrolysis of AE, AIP, and AIB, respectively: 16.4–49.7/θ 16.6–47.9/θ, and 16.4–42.8/θ, where θ = 2.303RT in kcal/mole. The flow dependence of kuni was used to estimate the collisional efficiencies of the azo compounds relative to the wall.