Charging A Negatively Curved Nanographene And Its Covalent Network

This study explores a bottom-up approach toward negatively curved carbon allotropes from octabenzo[8]circulene, a negatively curved nanographene. Stepwise chemical reduction reactions of octabenzo[8]circulene with alkali metals lead to a unique highly reduced hydrocarbon pentaanion, which is revealed by X-ray crystallography suggesting a local view for the reduction and alkali metal intercalation processes of negatively curved carbon allotropes. Polymerization of the tetrabromo derivative of octabenzo[8]circulene by the nickel-mediated Yamamoto coupling reaction results in a new type of porous carbon-rich material, which consists of a covalent network of negatively curved nanographenes. It has a specific surface area of 732 m(2) g(-1) and functions as anode material for lithium ion batteries exhibiting a maximum capacity of 830 mAh.g(-1) at a current density of 100 mA.g(-1). These results indicate that this covalent network presents the key structural and functional features of negatively curved carbon allotropes.