Tetrabenzoperipentacene: Stable Five-Electron Donating Ability and a Discrete Triple-Layered b-Graphite Form in the Solid State.

An oxidative ring-closure reaction of a tetranaphthylpyrene derivative led to the synthesis of a 56 all-carbon conjugated tetrabenzoperipentacene. In the single-crystal Xray structure, three molecules make a triple-layered cluster by p-stacking, wherein each layer rotates by 120°, and is thus considered a petit b-graphite. As for the optical properties, the Stokes shift is extremely small (10 cm^-1), thus indicating its remarkably rigid framework. The tetrabenzoperipentacene exhibits reversible five-electron oxidation waves in cyclic voltammetry, and is regarded as a counterpart to the fullerene C₆₀ in terms of stable multicharge-storage nanocarbon materials. [ABSTRACT FROM AUTHOR]