 The crystal structure of [C6(CH3)6]2+ (SbF6−)2 • HSO3F was obtained in 2017.Although the apical carbon atom is hexacoordinated, the rule of the tetravalency of carbon is still fulfilled.While the C-CH3 bond length of 1.479(3) Å is typical for a C-C single bond, the other five very long C-C distances of 1.694(2)-1.715(3) Å indicate a bond order of <1.