4-(4-Chlorophenyl)-4-hydroxypiperidinium benzoate

In the title salt, C11H15ClNO+·C7H5O2 −, the dihedral angle between the mean planes of the chlorophenyl ring of the cation and the benzene ring of the anion is 74.4 (1)°. In the cation, the six-membered piperazine ring adopts a chair conformation. The crystal packing is stabilized by intermolecular N—H⋯O and O—H⋯O hydrogen bonds, and weak intermolecular C—H⋯O, C—H⋯Cl and C—H⋯π interactions.

In the title salt, C 11 H 15 ClNO + ÁC 7 H 5 O 2 À , the dihedral angle between the mean planes of the chlorophenyl ring of the cation and the benzene ring of the anion is 74.4 (1) . In the cation, the six-membered piperazine ring adopts a chair conformation. The crystal packing is stabilized by intermolecular N-HÁ Á ÁO and O-HÁ Á ÁO hydrogen bonds, and weak intermolecular C-HÁ Á ÁO, C-HÁ Á ÁCl and C-HÁ Á Á interactions.
BPS thanks the University of Mysore for the research facilities. HSY is grateful to RL Fine Chem., Bengaluru, India, for a pure sample of 4-(4-chlorophynyl)-piperidin-4-ol. JPJ acknowledges the NSF-MRI program (grant No. CHE1039027) for funds to purchase the X-ray diffractometer.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: PV2415).
(a neuroleptic drug used to treat patients with psychotic illnesses, extreme agitation, or Tourette's syndrome) and loperamide (a synthetic piperidine derivative, effective against diarrhea resulting from gastroenteritis or inflammatory bowel disease).

Experimental
Solutions of 4-(4-chlorophenyl)-piperidin-4-ol (2.12 g, 0.01 mol) in methanol (10 ml) and benzoic acid (1.226 g, 0.01 mol) in methanol (10 ml) were mixed and stirred in a beaker at 333 K for 30 minutes. The mixture was kept aside for three days at room temperature. The salt thus obtained was filtered and dried in a vaccum desiccator over phosphorous pentoxide. The compound was recrystallized from N,N-dimethylformamide by slow evaporation (m.p: 498 -501 K).

Refinement
Hydrogen atoms on O1 and N1 were found from a Fourier difference map and were refined using DFIX 0.84(0.02) and 0.86(0.01) values for O-H and N-H distances, respectively, and U iso (H) = 1.2 times U eq (O/N). The rest of the H atoms were positioned geometrically, and allowed to ride on their parent atoms, with C-H distances 0.95 Å (CH) or 0.99 Å (CH 2 ) and U iso (H) = 1.18-1.21 times U eq (C).

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.