Enrofloxacinium picrate

Abstract

There is one cationanion pair in the asymmetric unit of the title compound [systematic name: 4-(3-carboxy-6-fluoro-4-oxo-1,4-dihydroquinolin-7-yl)-1- ethylpiperazin-1-ium 2,4,6-trinitrophenolate], C19H 23FN3O3+·C6H 2N3O7-. The sixmembered piperazine group in the cation adopts a slightly distorted chair conformation and contains a protonated N atom. The dihedral angles between the mean planes of the cyclopropyl and piperazine rings in the cation with the 10-atom ring system of the quinolone group are 48.1 (1) and 69.9 (5)°, respectively. The picrate anion interacts with the protonated N atom of an adjacent cation through a bifurcated N -H⋯O threecenter hydrogen bond, forming an R 1 2(6) ring motif. Furthermore, there is an intramolecular O -H⋯O hydrogen bond. The dihedral angle between the mean planes of the anion benzene and cation piperizine, quinoline and cyclopropyl rings are 61.3 (6), 31.1 (4) and 70.4 (9)°, respectively. The mean planes of the two o-NO2 and single p-NO2 groups in the picrate anion are twisted by 6.7 (6), 38.3 (9) and 12.8 (7)° with respect to the mean plane of the benzene ring. Strong N -H⋯O and weak intermolecular C -H⋯O hydrogen bonds in concert with weak π-π stacking interactions [centroidcentroid distances = 3.5785 (13), 3.7451 (12) and 3.6587 (13) Å] dominate the crystal packing.