Radical cations of quadricyclane and norbornadiene in polar ZSM-5 matrices: thermal retro Diels–Alder reaction
Abstract
The radical cation of norbornadiene or quadricyclane (Q) and of norbornadiene (NBD) produced by γ-radiolysis in polar ZSM-5 undergo a reverse Diels–Alder reaction, which is a thermally forbidden, photochemically allowed process, to cyclopentadiene radical cation.