1-{2-[2-(1H-Benzimidazol-1-yl)eth­oxy]eth­yl}-1H-benzimidazol-3-ium hexa­fluoro­phosphate

In the title salt, C(18)H(19)N(4)O(+)·PF(6) (−), the dihedral angle between the benzimidazolium and benzimidazole ring systems is 16.24 (2)°. In the cation, a π–π inter­action is observed between the imidazolium ring and the benzene ring of the benzimidazole ring system [centroid–centroid distance = 3.5713 (11) Å]. The PF(6) (−) ion is disordered over two sites, with occupancies of 0.895 (2) and 0.105 (2). In the crystal structure, pairs of N—H⋯N hydrogen bonds link the cations, forming centrosymmetric dimers. The dimers are linked via π–π inter­actions [centroid–centroid distance = 3.5606 (11) Å]. In addition, C—H⋯F hydrogen bonds are observed.