2-[2-(1H-Imidazol-3-ium-5-yl)eth-yl]-3-(pyridin-2-yl)-2H-imidazo[1,5-a]pyridin-4-ium bis-(perchlorate).

In the title mol-ecular salt, C(17)H(17)N(5) (+)·2ClO(4) (-), the dihedral angles between the fused-ring system and the pendant five- and six-membered heterocyclic rings are 6.4 (2) and 41.29 (19)°, respectively. The O atoms of both perchlorate anions are disordered over two sets of sites with occupancy ratios of 0.614 (8):0.386 (8) and 0.591 (7):0.409 (7). An intra-molecular C-H⋯N contact occurs in the cation. In the crystal, the components are linked by N-H⋯O and C-H⋯O hydrogen bonds and π-π stacking inter-actions [centroid-centroid separation = 3.642 (3) Å].