Crystal structure and Hirshfeld surface analysis of (E)-5-phenyl-3-[(pyridin-4-ylmethylidene)amino]thiazolidin-2-iminium bromide monohydrate

In the crystal structure of the title salt, the cations, anions and water molecules are linked into a three-dimensional network, which forms cross layers parallel to the (120) and (20) planes via O—H⋯Br, N—H⋯Br and N—H⋯N hydrogen bonds. C—H⋯π interactions also help in the stabilization of the molecular packing.


Supramolecular features and Hirshfeld surface analysis
As shown in Figs. 2 and 3, in the crystal, the cations, anions and water molecules are linked into a three-dimensional network, which forms cross layers parallel to the (120) and (120) planes via O-HÁ Á ÁBr, N-HÁ Á ÁBr and N-HÁ Á ÁN hydrogen bonds (Table 1). Furthermore, C-HÁ Á Á interactions also help in the stabilization of the molecular packing (Table 1).
Hirshfeld surface analysis was used to investigate the presence of hydrogen bonds and intermolecular interactions in the crystal structure. The Hirshfeld surface analysis (Spackman & Jayatilaka, 2009) of the title salt was generated by CrystalExplorer3.1 (Wolff et al., 2012), and comprised d norm surface plots and 2D (two-dimensional) fingerprint plots (Spackman & McKinnon, 2002 Table 1 Hydrogen-bond geometry (Å , ).

Figure 1
The molecular structure of the title salt. Displacement ellipsoids are drawn at the 30% probability level. H atoms are shown as spheres of arbitrary radius.

Figure 2
A view of the intermolecular hydrogen bonds of the title compound along the a axis.

Database survey
In a recent article of ours, which on the crystal structure of (E)-3-[(2,3-dichlorobenzylidene)amino]-5-phenylthiazolidin-2iminium bromide (Akkurt et al., 2018), the 3-N atom of the cation carries an N substituent, as found in the title compound. In the crystal, C-HÁ Á ÁBr and N-HÁ Á ÁBr hydrogen bonds link the components into a three-dimensional network with the cations and anions stacked along the b-axis direction. Weak C-HÁ Á Á interactions and inversion-related ClÁ Á ÁCl halogen bonds and C-ClÁ Á Á(ring) contacts also contribute to the molecular packing.

Figure 3
A view of the packing and intermolecular hydrogen bonding of the title compound along the c axis.

Figure 4
Hirshfeld surface of the title compound mapped over d norm .
racemate corresponds to the presence of both enantiomers at each site in the ratio 0.821 (3):0.179 (3). The system of hydrogen bonds connecting two cations and two anions into 12-membered rings is identical in the racemic and in the optically active crystals. YITCEJ (Martem'yanova et al., 1993a) is a product of the interaction of 2-amino-5-methylthiazoline with methyl iodide, with alkylation at the endocylic N atom, while YITCAF (Martem'yanova et al., 1993b) is a product of the reaction of 3-nitro-5-methoxy-, 3-nitro-5chloro-and 3-bromo-5-nitrosalicylaldehyde with the heterocyclic base to form the salt-like complexes.

Synthesis and crystallization
To the solution of 1 mmol of 3-amino-5-phenylthiazolidin-2iminium bromide in 20 ml ethanol was added 1 mmol of isonicotinaldehyde and the solution was refluxed for 2 h. The reaction mixture was then cooled. Reaction products were precipitated from the reaction mixture as colourless single crystals, collected by filtration and washed with cold acetone.

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.