Extensive theoretical and experimental studies have been performed on charged n-conjugated polybenzenoid systems in the last two decades.1J The scarcity of information on heterocyclic doubly charged species3 as well as the limited success in the preparation of nitrogen polyheterocyclic dian- ions4 prompted us to undertake the investigation of a sulphur-containing polycyclic dianion. In view of the weak- ness of the carbon-sulphur? bond, the preparation of such ...
