2-Methyl-imidazolium picrate

Acta Crystallogr Sect E Struct Rep Online. 2010 Dec 24;67(Pt 1):o235. doi: 10.1107/S1600536810053390.

Abstract

In both ionic components of the title salt, C(4)H(7)N(2) (+)·C(6)H(2)N(3)O(7) (-), the rings are approximately planar; the maximum deviation from the mean plane is an order of magnitude larger in the picrate ring [0.0289 (10) Å] than in the imidazolium ring [0.0028 (10) Å. The nitro groups are twisted with respect to the six-atom ring plane; the NO(2) groups next to the oxide O atom, at the 2- and 6-positions, are twisted more [by 53.59 (9) and 18.46 (12)°] than the NO(2) group at the 4-postition, for which the twist angle is 7.28 (16)°. In the crystal, N-H⋯O hydrogen bonds, in which the hydroxyl O atom acts as a double acceptor and one of the O atoms from a nitro group acts as an additional acceptor, connect mol-ecules into chains along the c-axis direction. Relatively short C-H⋯O contacts and π-π inter-actions between symmetry-related six-membered rings [centroid-centroid distances = 3.5938 (10) and 3.6223 (10) Å] also occur.