Triplex promoted intersystem crossing of ion–radical pairs in the photosensitized valence isomerization of quadricyclane: chemically induced dynamic nuclear polarization (CIDNP) evidence

Abstract

Photosensitized valence isomerization of quadricyclane to norbornadiene by dibenzoylmethanatoboron difluoride in the presence of durene shows a CIDNP effect which is opposite in direction to that occurring in the absence of durene, demonstrating possible participation of triplexes in the durene co-sensitized reaction.