9-aminoacridinum acridine-9-carboxylate (1) as a proton transfer ion pair was obtained by the reaction of 9-aminoacridine, acridine-9-carboxylic acid and zinc nitrate (1:1:1 molar ratio) in solvents mixture H₂O/MeOH under reflux condition. The crystal structure of this compound was determined by elemental analysis, IR spectroscopy and single crystal X-ray diffraction method. Crystallographic data for 1 was collected at 100 K.  The synthesized compound has been crystallized in monoclinic system with C2/c space group and a = 15.336 (9), b = 14.342(8), c = 19.481(1), β= 109.057(1) cell parameters. The final R value is 0.044 for 4425 independent reflections. There are various types of ionic and non-covalent interactions including N–H∙∙∙O hydrogen bonding, π-π stacking, and cationic-anionic interactions in the crystal structure of (1). This interactions play important role in the expansion of 3D network of (1).