THE REACTIVITY OF THE CYCLIC POLYENES TOWARDS FREE RADICALS: III. ADDITION OF THE ETHYL RADICAL

Abstract

Arrhenius parameters have been measured for the addition of the ethyl radical to cycloheptatriene-1,3,5 and to bicyclo[2.2.1]heptadiene-2,5 in the gas phase; the values for the energy of activation are distinct at 6.4 ± 0.2 and 7.0 ± 0.1 kcal/mole respectively. The addition of the ethyl radical to benzene, cyclohexadiene-1,4, and cyclooctadiene-1,5 proceeds too slowly to be detected. The significance of these results is considered in conjunction with those obtained previously for cyclohexadiene-1,3 and cyclooctatetraene, and the possibility of interpreting the reactivity of the cyclic polyenes in terms of molecular structure is discussed.