(R)-Doxylaminium (R, R)-tartrate

In the title compound (systematic name: (R)-dimethyl{2-[1-phenyl-1-(pyridin-2-yl)ethoxy] ethyl} azanium (R, R)-3-carboxy-2,3-dihydroxypropanoate), C17H23N2O+ center dot C4H5O6-, the doxylaminium cation is protonated at the N atom. The tartrate monoanions are linked by short, almost linear O-H center dot center dot center dot O hydrogen bonds into chains extended along [100]. These chains are interlinked by anion-pyridine O-H center dot center dot center dot N hydrogen bonds into a two-dimensional grid structure. WeakC-H center dot center dot center dot O interactions also play a role in the crystal packing. An intramolecular hydroxy-carboxylate O-H center dot center dot center dot O hydrogen bond influences the conformation of the anion: the hydrogen-bonded fragment is almost planar, the maximum deviation from the mean plane being 0.059 (14) angstrom. In the cation, the aromatic rings are almost perpendicular [dihedral angle = 84.94 (8)degrees] and the conformation of the O-C-C-N chain is gauche(-), the dihedral angle is -76.6 (2)degrees. The absolute configuration was assigned on the basis of known chirality of the parent compound.