3,3′-Dimethyl-1,1′-(butane-1,4-di­yl)diimidazolium bis­(tetra­fluoro­borate)

The title compound, C(12)H(20)N(4) (2+)·2BF(4) (−), was prepared by the anion exchange of a dibromide ionic liquid with sodium tetra­fluoro­borate. The asymmetric unit contains one half of the imidazolium cation, which lies about an inversion centre at the mid-point of the central C—C bond of the linking butyl chain. The two planar imidazole rings (r.m.s. deviation = 0.0013 Å) are strictly parallel and separated by 2.625 (7) Å [vertical distance between the centroids of two imidazole rings], giving the mol­ecule a stepped appearance. In the crystal structure, inter­molecular C—H⋯F hydrogen bonds link the cations and anions, generating a three-dimensional network.