An electron spin resonance study of the reactivity of organotin and organolead radicals

Abstract

Tri-n-butyltin radicals were prepared by photolysis of mixtures of t-butyl peroxide and hexa-n-butylditin. E.s.r. competition experiments gave activation energy differences for the abstraction of the halogen atom from 15 organic halides by the tri-n-butyltin radical. The results indicate that polar as well as enthalpy effects are important. Qualitative work on trimethyl-lead radicals, prepared by photolysis of hexamethyldilead, shows that ease of removal of halogen from organic halides by the trimethyl-lead radical decreases in the order allyl bromide > carbon tetrachloride > alkyl bromides > alkyl and allyl chlorides. S_H2 Displacements by t-butoxyl radicals of an alkyl radical from trialkyltin bromides, chlorides, and acetates, but not the hydrides, were observed.