Imipraminium picrate

The title compound, C19H25N2+center dot C6H2N3O7-, is a molecular salt arising from the reaction of imipramine and picric acid. The tertiary N atom of the side chain of the cation is protonated and forms a bifurcated N-H center dot center dot center dot(O,O) hydrogen bond to the anion. One of the acceptor O atoms is the deprotonated phenol O atom and the other is part of a nitro group. The dihedral angle between the mean planes of the benzene rings in the cation is 56.13 (6)degrees and the two bridging methylene groups in the central seven-membered ring are probably disordered. In the crystal structure, pi-pi stacking occurs [ring centroid separations = 3.6805 (12) and 3.7726 (14) angstrom], resulting in centrosymmetric associations of two cations and two anions.