Crystal structure of 1-(3-chloro-phen-yl)piperazin-1-ium picrate-picric acid (2/1).

ABSTRACT: The title salt {systematic name: bis-[1-(3-chloro-phen-yl)piperazinium 2,4,6-tri-nitro-phenolate]-picric acid (2/1)}, 2C10H14ClN2 (+)·2C6H5N3O7 (-)·C6H6N3O7, crystallized with two independent 1-(3-chloro-phen-yl)piperazinium cations, two picrate anions and a picric acid mol-ecule in the asymmetric unit. The six-membered piperazine ring in each cation adopts a slightly distorted chair conformation and contains a protonated N atom. In the picric acid mol-ecule, the mean planes of the nitro groups in the ortho-, meta-, and para-positions are twisted from the benzene ring by 31.5?(3), 7.7?(1), and 3.8?(2)°, respectively. In the anions, the dihedral angles between the benzene ring and the ortho-, meta-, and para-nitro groups are 36.7?(1), 5.0?(6), 4.8?(2)°, and 34.4?(9), 15.3?(8), 4.5?(1)°, respectively. The nitro group in one anion is disordered and was modeled with two sites for one O atom with an occupancy ratio of 0.627?(7):0.373?(7). In the crystal, the picric acid mol-ecule inter-acts with the picrate anion through a trifurcated O-H?O four-centre hydrogen bond involving an intra-molecular O-H?O hydrogen bond and a weak C-H?O inter-action. Weak inter-molecular C-H?O inter-actions are responsible for the formation of cation-anion-cation trimers resulting in a chain along [010]. In addition, weak C-H?Cl and weak ?-? inter-actions [centroid-centroid distances of 3.532?(3), 3.756?(4) and 3.705?(3)?Å] are observed and contribute to the stability of the crystal packing.

SUBMITTER: Kavitha CN 

PROVIDER: S-EPMC4257327 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature