Redetermination of the crystal structure of 2-oxo-1,3-thiazolidin-4-iminium chloride

2-Oxo-1,3-thiazolidin-4-iminium cations interact with a chloride anion via N—H⋯Cl hydrogen bonds, forming a supramolecular chain. These supramolecular chains are further extended by weak C—H⋯Cl, C—H⋯O and C—O⋯π intermolecular interactions forming a 3D supramolecular network.


Chemical context
Thiourea and its derivatives are an important group of organic compounds because of their diverse application in fields such as medicine, agriculture, coordination, and analytical chemistry (Saeed et al., 2010(Saeed et al., , 2014. The complexes with thiourea derivatives expressing biological activity have been successfully screened for various biological actions such as antibacterial, antifungal, anticancer, antioxidant, antiinflammatory, antimalarial, antiviral activity, as anti-HIV agents and also as catalysts (Saeed et al., 2010). Thiazolidine derivatives show antitumor activity as well as a broad range of biological activities including antibactericidal, fungicidal, antiangiogenesis, antidiabetic and antimicrobial (Singh et al., 1981;Saeed & Florke, 2006;Rizos et al., 2016). Thiourea derivatives are used as phase-change materials for thermal energy storage (Alkan et al., 2011). In addition, metal complexes of thiourea derivatives are also studied for their relationship to NLO materials (Rajasekaran et al., 2003;Ushasree et al., 2000). Thiourea derivatives find applications related to their uses as synthons in supramolecular chemistry (Saeed & Florke, 2006). Organic and inorganic complexes of thiourea derivatives form well-defined non-covalent supramolecular architectures via multiple hydrogen bonds involving the N, S and O atoms. We report herein the molecular structure and supramolecular architecture of the title salt, C 3 H 5 N 2 SO + CI À , (I), formed from the reaction of thiourea with monochloro acetic acid. A determination of this crystal structure was performed by Ananthamurthy & Murthy (1975). However, while the authors could identify the space group as Pbca and determine the cell parameters [a = 9.53 (1), b = 17.61 (5), c = 7.71 (1) Å ], these were not accurate enough to examine the hydrogen-bonding patterns and supramolecular interactions that are described here.

Figure 2
A view of a chain formed by N-HÁ Á ÁCl hydrogen bonds (dashed lines). Symmetry code as in Table 1.

Figure 3
A view of the two supramolecular R 4 2 (12) and R 8 4 (20) ring motifs in the structure of (I), formed by N-HÁ Á ÁCl hydrogen bonds (dashed lines). Symmetry codes are given in Table 1.

Synthesis and crystallization
Hot ethanol solutions of thiourea (32 mg) and chloro acetic acid (37 mg) were mixed in a 1:1 molar ratio. The resulting solution was warmed over a water bath for half an hour and then kept at room temperature for crystallization. After a week, light-yellow prismatic crystals suitable for single-crystal X-ray analysis were obtained. A view of the supramolecular sheet-like structures within the crystal packing of (I). Green dashed lines indicate N-HÁ Á ÁCl hydrogen bonds. Symmetry codes are given in Table 1.

Figure 5
A view of the weak C-OÁ Á Á interactions (dashed lines) in (I). Cg1 is the centroid of the thiazolidine ring. Symmetry codes are given in Table 1.

2-Oxo-1,3-thiazolidin-4-iminium chloride
Crystal data 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 > 2sigma(F 2 ) is used only for calculating R-factors(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.