CIDNP of 13C and 1H nuclei in the reactions of cyclohexadienone carbenes

Abstract
Thermal decomposition of 4‐diazo‐2,6‐di‐tert‐butyl‐2, 5‐cyclohexadien‐1‐one in perhalogenated solvents has been investigated. The decomposition reaction proceeds via a carbene intermediate first to a singlet and then to an effectively triplet free encounter radical pair formed in a halogen abstraction reaction. The polarisation of the stable reaction product is determined by competing processes in the primary cage, intersystem crossing and escape from the cage.