CYCLIC CONJUGATION IN PYRACYLENE

Abstract

Cyclic conjugation of the π-electrons in pyracylene is studied by means of the energyeffects (ef) of its various cycles. The calculated ef-values imply that cyclic conjugation significantly destabilizes the pyracylene molecule. This seems to contradict the experimental findings that pyracylene is a reasonably stable conjugated species. We show how this apparent failure of the theory can be avoided, and how the main features of pyracylene’s molecular geometry can be rationalized.