The Photolysis of Azoisopropane

Azoisopropane has been photolyzed by 3600 Å radiation over the temperature range 30–120 °C. The effect of pressure indicates an excited molecule mechanism. Excited molecules which decompose give nitrogen and isopropyl radicals; the latter either combine, disproportionate, or react with azoisopropane. The activation energy difference between the two reactions[Formula: see text]has been found to be 6.5 ± 0.5 kcal. per mole.The difference in activation energy between the disproportionation and combination reactions is rendered ambiguous by the possibility of C3H7.N:N existing at the lower temperatures; but this is certainly small. The ratio of the rates of the two reactions is 0.5 at room temperature.