1-Benzyl-imidazolium hexa-fluoro-phosphate-1-benzyl-imidazole (1/1).

In the title compound, C(10)H(11)N(2) (+)·PF(6) (-)·C(10)H(10)N(2), the H atom involved in protonation is disordered equally between the cation and the neutral mol-ecule. The dihedral angle between the phenyl and imidazole rings is 82.6 (2)°. In the crystal structure, there are head-to-tail π-π stacking inter-actions between imidazole rings; the inter-planar separation is 3.295 (1) Å and the centroid-centroid separation is 3.448 (3) Å. In the centrosymmetric anion, two F atoms are disordered over two positions; the refined site-occupancy factors are 0.855 (11) and 0.145 (11).