Isomerization kinetics of partly delocalized radicals observed by muon spin rotation

Barriers to isomerization by rotation about a partial double bond in ..cap alpha..-carbonyl-, ..cap alpha..-carboxyl-, and ..cap alpha..-carbamide-substituted alkyl radicals have been determined by means of the technique of muon spin rotation. They agree with those observed previously by electron spin resonance but are higher than the thermochemically determined stabilization energies of similar species.