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

In the redetermination of the title compound, C₃H₅N₂OS⁺·CI⁻, the asymmetric unit consists of one independent 2-oxo-1,3-thia­zolidin-4-iminium cation and one independent chloride anion. The cation inter­acts with a chloride anion via N—H⋯Cl hydrogen bonds forming a supra­molecular chain along [010]. These supra­molecular chains are further extended by weak C—H⋯Cl and C—H⋯O inter­actions, forming a two-dimensional network parallel to (001). The crystal structure is further stabilized by weak C—O⋯π inter­actions, supporting a three-dimensional architecture. The structure was previously determined by Ananthamurthy & Murthy [Z. Kristallogr. (1975). 8, 356–367] but has been redetermined with higher precision to allow the hydrogen-bonding patterns and supra­molecular inter­actions to be investigated.

1. 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, 2014). The complexes with thio­urea derivatives expressing biological activity have been successfully screened for various biological actions such as anti­bacterial, anti­fungal, anti­cancer, anti­oxidant, anti-inflam­matory, 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, anti-angiogenesis, 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, C₃H₅N₂SO⁺CI⁻, (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.

2. Structural commentary

The asymmetric unit of the title compound (I) consists of one 2-imino-4-oxo-1,3-thia­zolidine cation and one hydro­chloride anion (Fig. 1). In the cation, the C3=N1 bond has double-bond character. The C3—N1 and C3—N2 bond distances indicate tautomerism between the amino N1 and imino N2 groups. The exocylic bond [C3—N1 = 1.2930 (17) Å] is short and its length is comparable with that of the endocylic C3—N2 bond [1.3432 (16) Å], confirming the C3=N1 double-bond assignment. The bond lengths and angles agree with those reported for similar structures (Ananthamurthy & Murthy, 1975; Xuan et al., 2003; Vedavathi & Vijayan, 1981).

Figure 1 Asymmetric unit of the title compound, showing the atom-numbering scheme and 50% probability displacements ellipsoids. The dashed line represents the N2—H4⋯Cl1 hydrogen bond.

3. Supra­molecular features

The 2-imino-4-oxo-1,3-thia­zolidine cation inter­acts with the chlorine anion in the asymmetric unit via the N2—H4⋯Cl hydrogen bond (Table 1) and with symmetry-related Cl⁻anions via N1—H1⋯Cl and N1—H3⋯Cl hydrogen bonds, forming supra­molecular chains along [010] (Fig. 2). The chlorine anion inter­acts with the N2 atom and the exocyclic N1 atom of the thia­zolidine moiety through the N2—H4⋯Cl hydrogen bond and the pair of N1—H1⋯Cl and N1—H3⋯Cl hydrogen bonds, forming R₂⁴(12) ring motifs in the [010] plane (Fig. 3). This motif is further connected on the other side by R₄⁸(20) ring motifs, generating a sheet-like structure parallel to (001) (Fig. 4). The supra­molecular sheets and crystal packing are further stabilized by weak C—H⋯Cl, C—H⋯O and C=O⋯π inter­actions (Table 1, Fig. 5). All of these inter­actions combine to generate a three-dimensional supra­molecular architecture (Fig. 6).

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the S1/N1/C1–C3 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯Cl1^i	0.86	2.32	3.1484 (15)	162
N1—H3⋯Cl1^ii	0.86	2.34	3.1903 (15)	170
N2—H4⋯Cl1	0.86	2.26	3.1026 (12)	166
C2—H2⋯Cl1^iii	0.97	2.78	3.7137 (14)	163
C2—H5⋯O1^iv	0.97	2.57	3.5190 (18)	165
C1—O1⋯Cg1^v	1.20 (1)	3.13 (1)	3.9430 (15)	125 (1)
Symmetry codes: (i) -x+1, -y+1, -z+2; (ii) ; (iii) ; (iv) ; (v) .

Figure 2 A view of a chain formed by N—H⋯Cl hydrogen bonds (dashed lines). Symmetry code as in Table 1.

Figure 3 A view of the two supra­molecular R2^4(12) and R4^8(20) ring motifs in the structure of (I), formed by N—H⋯Cl hydrogen bonds (dashed lines). Symmetry codes are given in Table 1.

Figure 4 A view of the supra­molecular sheet-like structures within the crystal packing of (I). Green dashed lines indicate N—H⋯Cl hydrogen bonds. Symmetry codes are given in Table 1.

Figure 5 A view of the weak C—O⋯π inter­actions (dashed lines) in (I). Cg1 is the centroid of the thia­zolidine ring. Symmetry codes are given in Table 1.

Figure 6 A view of the three-dimensional architecture of the title compound.

4. Database survey

The crystal structures of a number of related and substituted thio­urea derivatives and thia­zoline salts and their metal complexes have also been investigated in a variety of crystalline environments. These include DL-2-amino-2-thia­zoline-4-carb­oxy­lic acid trihydrate (Xuan et al., 2003), 2-amino-1,3-thia­zoline hydro­chloride (Vedavathi & Vijayan, 1981), N-(4-chloro­benzo­yl)-N,N-di­phenyl­thio­urea (Arslan et al., 2003a), 1-(4-chloro-benzo­yl)-3-naphthalen-1-yl-thio­urea (Arslan et al., 2003b) and 1–(4–chloro­phen­yl)–3–(4–μethyl­benzo­yl)thio­urea (Saeed & Floörke, 2006). N—H⋯Cl hydrogen bonds play a major role in building up the supra­molecular architectures of many related crystal structures (for examples, see: Diallo et al., 2014; Yamuna et al., 2014; Plater & Harrison, 2016; Khongsuk et al., 2015).

5. 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.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. All H atoms were initially located in difference-Fourier maps and were subsequently treated as riding atoms in geometrically idealized positions, with C—H = 0.93 and N—H = 0.86 and with U_iso(H) = 1.2U_eq(C,N).

Table 2
Experimental details

Crystal data
Chemical formula	C3H5N2OS^+·Cl^−
Mr	152.60
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	296
a, b, c (Å)	7.5106 (11), 9.3140 (13), 17.343 (3)
V (Å^3)	1213.2 (3)
Z	8
Radiation type	Mo Kα
μ (mm^−1)	0.87
Crystal size (mm)	0.54 × 0.45 × 0.25
Data collection
Diffractometer	Bruker SMART APEXII DUO CCD area detector
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
Tmin, Tmax	0.683, 0.832
No. of measured, independent and observed [I > 2σ(I)] reflections	7517, 1798, 1554
Rint	0.020
(sin θ/λ)max (Å^−1)	0.708
Refinement
R[F^2 > 2σ(F^2)], wR(F^2), S	0.027, 0.077, 1.05
No. of reflections	1798
No. of parameters	73
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å^−3)	0.33, −0.22
Computer programs: APEX2 and SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008), PLATON (Spek, 2009), Mercury (Macrae et al., 2008) and PLATON (Spek, 2009).

Supporting information

Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009) and Mercury (Macrae et al., 2008); software used to prepare material for publication: PLATON (Spek, 2009).

2-Oxo-1,3-thiazolidin-4-iminium chloride

Crystal data

C3H5N2OS^+·Cl^−	Dx = 1.671 Mg m^−3
Mr = 152.60	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbca	Cell parameters from 1800 reflections
a = 7.5106 (11) Å	θ = 2.4–30.2°
b = 9.3140 (13) Å	µ = 0.87 mm^−1
c = 17.343 (3) Å	T = 296 K
V = 1213.2 (3) Å^3	Prism, yellow
Z = 8	0.54 × 0.45 × 0.25 mm
F(000) = 624

Data collection

Bruker SMART APEXII DUO CCD area detector diffractometer	1798 independent reflections
Radiation source: fine-focus sealed tube	1554 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
phi and ω scans	θmax = 30.2°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −10→10
Tmin = 0.683, Tmax = 0.832	k = −10→13
7517 measured reflections	l = −24→20

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.027	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.077	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0384P)^2 + 0.4007P] where P = (Fo^2 + 2Fc^2)/3
1798 reflections	(Δ/σ)max = 0.001
73 parameters	Δρmax = 0.33 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	0.37439 (5)	−0.01239 (4)	0.86421 (2)	0.03155 (11)
O1	0.67766 (16)	0.25652 (11)	0.75866 (7)	0.0389 (2)
N1	0.3380 (2)	0.18329 (15)	0.97467 (7)	0.0409 (3)
H1	0.3567	0.2663	0.9949	0.049*
H3	0.2747	0.1209	0.9988	0.049*
C3	0.40497 (18)	0.15240 (14)	0.90803 (7)	0.0270 (3)
C2	0.51618 (18)	0.03829 (13)	0.78499 (7)	0.0272 (3)
H5	0.6172	−0.0263	0.7817	0.033*
H2	0.4507	0.0336	0.7368	0.033*
C1	0.57886 (18)	0.18932 (13)	0.79961 (7)	0.0264 (3)
N2	0.50511 (14)	0.24392 (11)	0.86677 (6)	0.0268 (2)
H4	0.5224	0.3312	0.8812	0.032*
Cl1	0.63837 (5)	0.54422 (4)	0.91839 (2)	0.03440 (11)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0393 (2)	0.02303 (17)	0.03232 (19)	−0.00807 (13)	0.00667 (13)	−0.00457 (12)
O1	0.0438 (6)	0.0310 (5)	0.0418 (6)	−0.0042 (5)	0.0099 (5)	0.0066 (4)
N1	0.0593 (9)	0.0310 (6)	0.0325 (6)	−0.0057 (6)	0.0111 (6)	−0.0077 (5)
C3	0.0311 (6)	0.0224 (5)	0.0275 (6)	−0.0007 (5)	−0.0013 (5)	−0.0025 (4)
C2	0.0301 (6)	0.0255 (6)	0.0261 (6)	−0.0020 (5)	0.0015 (5)	−0.0030 (4)
C1	0.0281 (6)	0.0223 (5)	0.0289 (6)	0.0021 (5)	−0.0022 (5)	0.0028 (4)
N2	0.0312 (5)	0.0188 (5)	0.0304 (5)	−0.0014 (4)	−0.0018 (4)	−0.0022 (4)
Cl1	0.0453 (2)	0.02841 (18)	0.02950 (18)	−0.00821 (13)	0.00436 (13)	−0.00460 (12)

Geometric parameters (Å, º)

S1—C3	1.7280 (13)	C3—N2	1.3432 (16)
S1—C2	1.8013 (14)	C2—C1	1.5049 (18)
O1—C1	1.2027 (17)	C2—H5	0.9700
N1—C3	1.2930 (17)	C2—H2	0.9700
N1—H1	0.8600	C1—N2	1.3865 (17)
N1—H3	0.8600	N2—H4	0.8600
C3—S1—C2	91.38 (6)	C1—C2—H2	110.2
C3—N1—H1	120.0	S1—C2—H2	110.2
C3—N1—H3	120.0	H5—C2—H2	108.5
H1—N1—H3	120.0	O1—C1—N2	123.48 (12)
N1—C3—N2	123.56 (12)	O1—C1—C2	125.45 (12)
N1—C3—S1	122.62 (11)	N2—C1—C2	111.06 (11)
N2—C3—S1	113.82 (9)	C3—N2—C1	116.00 (11)
C1—C2—S1	107.55 (9)	C3—N2—H4	122.0
C1—C2—H5	110.2	C1—N2—H4	122.0
S1—C2—H5	110.2
C2—S1—C3—N1	−176.63 (14)	N1—C3—N2—C1	174.68 (14)
C2—S1—C3—N2	2.92 (11)	S1—C3—N2—C1	−4.87 (15)
C3—S1—C2—C1	−0.44 (10)	O1—C1—N2—C3	−176.60 (14)
S1—C2—C1—O1	179.02 (12)	C2—C1—N2—C3	4.40 (16)
S1—C2—C1—N2	−2.00 (13)

Hydrogen-bond geometry (Å, º)

Cg1 is the centroid of the S1/N1/C1–C3 ring.

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl1^i	0.86	2.32	3.1484 (15)	162
N1—H3···Cl1^ii	0.86	2.34	3.1903 (15)	170
N2—H4···Cl1	0.86	2.26	3.1026 (12)	166
C2—H2···Cl1^iii	0.97	2.78	3.7137 (14)	163
C2—H5···O1^iv	0.97	2.57	3.5190 (18)	165
C1—O1···Cg1^v	1.20 (1)	3.13 (1)	3.9430 (15)	125 (1)

Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) x−1/2, −y+1/2, −z+2; (iii) −x+1, y−1/2, −z+3/2; (iv) −x+3/2, y−1/2, z; (v) x+1/2, y, −z+3/2.