Flupentixol tartrate

In the title salt, C23H26F3N2OS+·C4H5O6 − [systematic name: 1-(2-hydroxyethyl)-4-[3-(2-(trifluoromethyl)thioxanthen-9-ylidene)propyl]piperazin-1-ium 3-carboxy-2,3-dihydroxypropionate], the monoprotonated piperazine ring in the cation adopts a chair conformation, while the thiopyran ring of the thioxanthene group has a boat conformation. The dihedral angle between the mean planes of the two outer aromatic rings of the thioxanthene groups is 31.6 (2)°. In the crystal, the cations and anions are linked via O—H⋯O, N—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds, forming chains propagating along [100]. In addition, R 2 2(7), R 2 2(11), R 2 2(10) and R 2 2(12) graph-set ring motifs involving the anions, and R 2 2(9) graph-set ring motifs involving both the cations and anions are observed. The three F atoms of the trifluoromethyl group are disordered over two sets of sites and the individual atoms were refined with occupancy ratios of 0.54 (6):0.46 (6), 0.72 (2):0.28 (2) and 0.67 (3):0.33 (3).


Experimental
A gift sample of flupentixol was donated by R. L. Fine Chemicals. The title salt was prepared by mixing flupentixol (0.2 g, 4.602 mmol) and tartaric acid (0.07 g, 4.602 mmol) dissolved in 5 mL of dimethyl formamide. The mixture was stirred at 320 K for 30 minutes. X-ray quality colourless block-like crystals were obtained on slow evaporation of the reaction mixture (M.p: 468-474 K).

Refinement
The NH H atom was located in a difference Fourier map and freely refined. All of the other H atoms were placed in

Figure 1
A view of the molecular structure of the title salt, with atom labelling. The displacement ellipsoids are drawn at the 30% probability level. Hydrogen bonds are shown as dashed lines (see Table 1 for details).  A view along the b axis of the crystal packing of the title compound showing the R 2 2 (9) graph set ring motifs involving cations and anions. The hydrogen bonds are shown as dashed lines (see Table 1 for details; H atoms not involved in hydrogen bonding have been omitted for clarity).

Figure 3
A view along the a axis of the crystal packing of the title compound showing the R 2 2 (7), R 2 2 (11), R 2 2 (10) and R 2 2 (12) graph set ring motifs involving the anions. The hydrogen bonds are shown as dashed lines (see Table 1 for details; H atoms not involved in hydrogen bonding have been omitted for clarity).

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.