An azonia derivative of hexahelicene

In 8a‐azonia­6]­helicene hexa­fluoro­phos­phate or 8a‐azoniaphenanthro3,4‐c]phen­an­threne hexa­fluoro­phos­phate, C₂₅H₁₆N⁺·PF₆^?, replacement of an outer bridgehead carbon of hexahelicene by a quaternary Nsp² atom results in a geometrical change in the helical structure. The racemic heterohelicene forms homochiral columnar stacks through intermolecular π–π donor–acceptor interactions in the crystalline state.