Two new types of π-conjugation between a fullerene sphere and an addend

Diazirine addition reactions to C(60), followed by an HCl elimination step, yielded [6,6] and [5,6] sp(2) carbon bridged fullerenes. The [5,6] adducts (alkylidenehomofullerenes) are the first examples of fullerene structures where the addend is attached to the fullerene cage in a true, albeit highly bent, alternating single-double bond fashion.