New Fullerene Electronic Acceptors and Acids

Significance

Fullerenes, especially C₆₀ derivatives, are widely used as electronic acceptors for charge separation in organic photovoltaic technologies. More powerful acceptors were generated by placing cyano groups on C₆₀ to generate C₆₀(CN)₄. Anionic forms of C₆₀ containing one or three cyano groups can be protonated to produce strong Brønsted acids C₆₀HCN and C₆₀H(CN)₃. Proton conduction by protonated fullerenes is potentially interesting for fuel-cell applications.