From tetrabenzoheptafulvalene to sp2 carbon nano-rings†
Herein we report a new strategy to construct nano-rings of sp2 carbon by taking advantage of the “C” shape of syn-tetrabenzoheptafulvalene. This strategy led to the successful synthesis of an sp2 carbon nano-ring containing a tetrabenzoheptafulvalene moiety fused with tetraphenylene. However, attempts to synthesize a more strained nano-ring of sp2 carbon using the same strategy only yielded an oxygen-bridged nano-ring with the step of aromatization being unsuccessful. Both the nano-rings were unambiguously characterized by X-ray crystallography.