Self sensitized photooxidation of tetrathienyltetrathiafulvalenes: synthesis of thienyl substituted 1,2,5,8-tetrathiecine-6,7-dione, a new heterocyclic system

Irradiation of tetrathienyltetrathiafulvalenes in an oxygen saturated solution gives tetrathienyl substituted 1,2,5,8-tetrathiecine-6,7-diones, via singlet oxygen generation followed by cycloaddition onto the TTF double bond and a final rearrangement process. The thermal and photochemical behaviour and reductive methylation of this new class of macro-heterocyclic system have also been investigated.