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(+)center dot PF(6)(-), the dihedral angle between the benzimidazolium and benzimidazole ring systems is 16.24 (2)degrees. In the cation, a pi-pi interaction is observed between the imidazolium ring and the benzene ring of the benzimidazole ring system [centroid-centroid distance = 3.5713 (11) angstrom]. 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 center dot center dot center dot N hydrogen bonds link the cations, forming centrosymmetric dimers. The dimers are linked via pi-pi interactions [centroid-centroid distance = 3.5606 (11) angstrom]. In addition, C-H center dot center dot center dot F hydrogen bonds are observed.