Reactions of the ethynyl radical. Part 2.—With alkenes

Abstract

Ethynyl radicals, from the 2537 Å photolysis of bromoacetylene, have been reacted with C₂-C₆ monolefins with and without the addition of nitric oxide. Hydrogen abstraction occurs, and also addition of ethynyl to the π-bond followed by a displacement process giving conjugated or unconjugated enynes. The rates of these reactions have been measured relative to the formation of C₄H₂ by attack on bromoacetylene. The mechanism of the addition reaction is discussed.