Photoinduced electron transfer from 7-methylenenorbornadiene, MN, and 7-methylenequadricyclane, MQ, to an excited sensitizer/acceptor in the presence of methanol generates products of several structure types. All products require nucleophilic capture of the radical cations, MN·+ and MQ·+, by methanol, followed by rapid rearrangements of the resulting free radicals to C· as the key intermediate. The short lifetime of the primary products of capture is ascribed to the allylic nature of their C4—C5 bonds. The stereochemistry of the methoxy groups in the products indicates that the nucleophile attacks MQ·+ exclusively from the “exo” face (“backside” attack), whereas MN·+ shows, in addition, a limited degree of attack from the “endo” face.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry