Electron-Transfer-Induced Rearrangements: Radical Cations of Bridged Bicyclobutanes

Article abstract of DOI:10.1021/ja00300a010

The reaction of several bridged bicyclobutanes, 1-7, with photoexcited electron acceptors gives rise to strong nuclear spin polarization effects.These results are interpreted in terms of two different types of radical cation intermediates in which spin and charge are localized either in the transannular bicyclobutane bond (A) or in a ? orbital of the bridging moiety (B). he chemical nature of the bridging unit determines the radical cation structures and influences the rearrangement pathways.