Hydrocarbon Molecules with Novel Structure: the First Fullerene Derivative Having a Fulvene-Type p-System and Polycyclic Aromatics Having s-p Conjugation (ORGANIC MATERIALS CHEMISTRY-High-Pressure Organic Chemistry)

Abstract

A spacious p-conjugated carbanion such as fluorenyl anion was found to add to fullerene C60 with high positional selectivity to afford the first tetrakisadduct of C60 having a fulvene-type p-electronic system on its spherical surface. This derivative reacts with various carbon nucleophiles at the fulvene's “exocyclic” sp2 carbon to give the corresponding cyclopentadienide ion. Also synthesized were the polycyclic aromatic hydrocarbons fully annelated with a rigid bicyclic framework, i.e. bicyclo[2.2.2]octene. These planar polycyclic systems are characterized by the high oxidizability affording stable cation radicals and dications.