Etoricoxibium picrate

In the cation of the title salt (systematic name: 5-{5-chloro-3-[4-(methyl­sulfon­yl)phen­yl]-2-pyrid­yl}-2-methyl­pyridinium 2,4,6-trinitro­phenolate), C(18)H(16)ClN(2)O(2)S(+)·C(6)H(2)N(3)O(7) (−), the mean planes of the two pyridine rings in the bipyridine unit are twisted by 33.9 (2)° with respect to each other. The dihedral angles between the mean planes of the sulfonyl­benzene ring and the chloro­pyridine and methyl­pyridine rings are 51.2 (0) and 49.3 (9)°, respectively. The picrate anion inter­acts with the protonated N atom through a bifurcated N—H⋯(O,O) hydrogen bond, forming an R (1) (2)(6) ring motif with the N atom from the methyl­pyridine group of an adjacent cation. N—H⋯O hydrogen bonds, weak C—H⋯O and π–π stacking inter­actions [centroid–centroid distances = 3.8192 (9)and 3.6749 (9)] occur in the crystal packing, creating a two-dimensional network structure along [110].