Hydrogen bonding in 2-(2-oxothia­zolidin-3-yl)-4,5-dihydro­thia­zolium hydrogen sulfate monohydrate

The asymmetric unit of the title compound, C₆H₉N₂OS₂⁺·HSO₄^-·H₂O, contains a heterocyclic cation, a hydrogen sulfate anion and a water mol­ecule. There are strong hydrogen bonds between the hydrogen sulfate anions and water mol­ecules, forming an infinite chain along the [010] direction, from which the cations are pendent. The steric, electronic and geometric features are compared with those of similar compounds. In this way, structural relationships are stated in terms of the influence of the sulfate group on the protonation of the heterocycle and on the tautomeric equilibrium in the solid state.

S1. Comment

Thiazolidinone derivatives are attractive targets for drug synthesis (Lesyk & Zimenkovsky, 2004) because these pharmacologically active compounds present various biological properties. For instance, antitumour (Lesyk et al., 2006), antimicrobial (Vicini et al., 2006), antidiarrhoeal (Mazzoni et al., 2006), anti-inflammatory (Ottanà et al., 2005) and antioxidant activities (Shimizu et al., 2002) have been attributed to them. In addition, they are potentially useful for neuropathic pain treatment (Shimizu et al., 2002). The synthesis and spectroscopic analysis of the title compound, (I), have been described previously (Hanefeld & Gunes, 1986). In the present paper, we report the structure of (I) (Fig. 1). A related compound, the monohydrated hydrogen sulfate salt of bis(pyrimethamine), crystallizes in the same space group (P2₁2₁2₁) as (I) (Devi et al., 2006). Therefore, the presence of the hydrogen sulfate anion and the water molecule may play an important role in the assembly of these compounds.

The intramolecular geometric parameters of (I) were compared with those of similar structures deposited in the Cambridge Structural Database (CSD, Version?; Allen, 2002) using Mogul (Bruno et al., 2004). The lengths of the C1—N1 [1.408 (3) Å] and C1═O1 [1.218 (3) Å] bonds are typical of their types [average values 1.40 (1) and 1.21 (2) Å, respectively]. The length of the N1—C4 bond which links the two rings [1.357 (3) Å] is very similar to that of the corresponding bond [1.350 (5) Å] in the analogous compound, 1-(5-nitro-1,3-thiazol-2-yl)-2-imidazolidinone (Peeters et al., 1984), and these values are both typical for bonds of this type [average value 1.35 (1) Å].

Each of the rings adopts an envelope conformation, with atoms C2 and C6 in the flap positions of the 2-thiazolidinone and 2-thiazolyl groups, respectively. The largest deviation from the least-squares plane through the five atoms of the 2-thiazolidinone ring occurs for atom C2 [displacement 0.094 (2) Å], with an r.m.s. deviation of 0.0682 Å for the ring atoms. In the 2-thiazolyl ring, the largest displacement is for atom C6 [0.78 (22) Å], with an r.m.s. deviation of 0.0547 Å. The non-planarity of the rings arises from the adjacent CH₂ groups within each ring (Raper et al., 1983; Corrêa et al., 2006). The dihedral angle between the mean planes of the two rings in the cation is only 2.1 (2)°, so that overall the cation is close to being planar.

Within the anion, the S—OH distance of 1.539 (2) Å is clearly distinct from the other three S—O distances, which are in the range 1.422 (2)–1.437 (2) Å, indicating that the H-atom site is static, rather than mobile between the O atoms. The O—S—O bond angles [103.9 (2)–114.2 (2)°] are typical of those found in hydrogen sulfate anions in crystalline salts.

The crystal packing of (I) is strongly stabilized by a network of hydrogen bonds (Table 1). Moreover, the presence of the water molecule and the hydrogen sulfate anion play a key role in the molecular aggregation, where the anions and water molecules form a helical chain of edge-fused hydrogen-bonded rings running along along the [100] direction (Fig. 2). Atom O5 acts as an acceptor from two neighbouring water molecules, while atom O1W acts as acceptor from the anion. The cation is linked to the anion via a strong N—H···O hydrogen bond (Table 1), so that the cations are all pendent from the water/anion chains.

Other hydrated sulfate and hydrogen sulfate salts containing organic cations have been described, in which the inorganic components form dimers (Lu et al., 2004), chains (Gomes et al., 1996), or networks in two and three dimensions (Warden et al., 2004; Białońska & Ciunik, 2005). In 4-carboxyphenylammonium perchlorate monohydrate (Athimoolam & Natarajan, 2006), the water molecules and the anions form chains of edge-fused hydrogen-bonded rings which resemble those reported here for (I).

S2. Experimental

The title compound was synthesized according a minor modification of the reported procedure (Hanefeld & Gunes, 1986), in which hydrogen peroxide was used as the oxidant instead of nitric acid. Prism-shaped [Needle in CIF tables - please clarify] colourless single crystals of (I) were obtained by slow evaporation of a solution in diethyl ether. The hydrogen sulfate and water components are by-products of the synthetic procedure.

S3. Refinement

Methylene, amine and hydroxyl H atoms were placed in idealized locations and refined using a riding model, with U_iso(H) = 1.2U_eq(C_methylene, N_amine) or U_iso(H) = 1.5U_eq(O_hydroxyl), and with C—H = 0.97 Å, N—H = 0.86 Å and O—H = 0.82 Å. Water H atoms were permitted to ride at the position derived from the difference maps, with U_iso(H) = 1.5U_eq(O_water), giving O—H distances of 0.85 Å.

Computing details

Data collection: COLLECT (Nonius, 2000); cell refinement: SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO (Otwinowski & Minor, 1997) and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. The structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Dashed lines indicate hydrogen bonds.
	Fig. 2. The hydrogen bonds linking the water molecules and hydrogen sulfate anions of (I). [Symmetry codes: (i) x - 1, y, z; (ii) x - 1/2, -y + 1/2, -z; (iii); x + 1/2, -y + 1/2, -z; (iv) x + 1, y, z.]

2-(2-oxothiazolidin-3-yl)-4,5-dihydrothiazolium hydrogen sulfate monohydrate

Crystal data

C6H9N2OS2^+·HO4S^−·H2O	F(000) = 632
Mr = 304.36	Dx = 1.711 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 10761 reflections
a = 5.8508 (2) Å	θ = 2.9–27.5°
b = 13.0999 (4) Å	µ = 0.65 mm^−1
c = 15.4187 (5) Å	T = 294 K
V = 1181.84 (7) Å^3	Needle, colourless
Z = 4	0.14 × 0.05 × 0.03 mm

Data collection

Nonius KappaCCD diffractometer	2266 reflections with I > 2σ(I)
CCD scans	Rint = 0.056
Absorption correction: analytical (Alcock, 1970)	θmax = 27.5°, θmin = 3.1°
Tmin = 0.878, Tmax = 0.966	h = −7→7
14972 measured reflections	k = −16→16
2712 independent reflections	l = −18→19

Refinement

Refinement on F^2	H-atom parameters constrained
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.0645P)^2 + 0.1721P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.040	(Δ/σ)max < 0.001
wR(F^2) = 0.106	Δρmax = 0.25 e Å^−3
S = 1.03	Δρmin = −0.43 e Å^−3
2712 reflections	Absolute structure: Flack (1983), with 1126 Friedel pairs
158 parameters	Absolute structure parameter: −0.04 (10)
0 restraints

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

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

	x	y	z	Uiso*/Ueq
C1	−0.2155 (5)	0.67390 (19)	0.06591 (18)	0.0387 (6)
C2	0.0215 (7)	0.6715 (3)	0.2066 (2)	0.0718 (12)
H2A	0.1208	0.7213	0.2339	0.086*
H2B	−0.0198	0.6207	0.2496	0.086*
C3	0.1430 (5)	0.6217 (2)	0.13284 (18)	0.0446 (6)
H3A	0.2773	0.661	0.1173	0.054*
H3B	0.1917	0.5536	0.1494	0.054*
C4	0.0405 (5)	0.5646 (2)	−0.01473 (17)	0.0352 (5)
C5	0.0866 (7)	0.4898 (3)	−0.1634 (2)	0.0620 (9)
H5A	0.0146	0.4317	−0.1911	0.074*
H5B	0.1587	0.531	−0.208	0.074*
C6	0.2599 (7)	0.4543 (3)	−0.1011 (2)	0.0725 (11)
H6A	0.2413	0.3818	−0.0903	0.087*
H6B	0.4121	0.4657	−0.1241	0.087*
N1	−0.0136 (4)	0.61595 (17)	0.05889 (14)	0.0347 (5)
N2	0.2291 (4)	0.51180 (18)	−0.02068 (16)	0.0438 (5)
H2	0.3291	0.5109	0.0202	0.053*
O1	−0.3565 (4)	0.68092 (16)	0.00813 (14)	0.0506 (5)
S1	−0.23042 (15)	0.73305 (6)	0.16645 (5)	0.0558 (2)
S2	−0.12763 (14)	0.56517 (6)	−0.10671 (5)	0.0469 (2)
O1W	0.2293 (5)	0.2342 (2)	0.09439 (17)	0.0673 (7)
H1W	0.1245	0.2783	0.0871	0.101*
H2W	0.2854	0.2204	0.045	0.101*
O2	0.5575 (5)	0.46676 (19)	0.10722 (19)	0.0703 (7)
O3	0.5760 (5)	0.3030 (2)	0.17587 (18)	0.0719 (8)
H3	0.4769	0.2847	0.1416	0.108*
O4	0.8613 (5)	0.42366 (18)	0.20498 (16)	0.0662 (7)
O5	0.8428 (5)	0.3492 (2)	0.06472 (18)	0.0786 (8)
S3	0.71458 (12)	0.39105 (5)	0.13578 (5)	0.03976 (18)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0363 (13)	0.0374 (13)	0.0423 (14)	0.0025 (11)	0.0022 (12)	0.0058 (11)
C2	0.071 (2)	0.094 (3)	0.050 (2)	0.030 (2)	−0.0205 (19)	−0.0260 (19)
C3	0.0367 (14)	0.0571 (17)	0.0401 (14)	0.0013 (13)	−0.0074 (12)	−0.0013 (13)
C4	0.0349 (13)	0.0351 (11)	0.0355 (13)	−0.0031 (11)	0.0027 (10)	0.0045 (11)
C5	0.080 (3)	0.061 (2)	0.0454 (18)	0.0045 (19)	0.0001 (18)	−0.0097 (15)
C6	0.057 (2)	0.096 (3)	0.064 (2)	0.016 (2)	−0.0003 (19)	−0.035 (2)
N1	0.0331 (11)	0.0379 (10)	0.0331 (11)	0.0028 (10)	−0.0025 (9)	−0.0001 (9)
N2	0.0389 (13)	0.0493 (12)	0.0433 (13)	0.0051 (11)	−0.0019 (11)	−0.0060 (10)
O1	0.0403 (11)	0.0622 (13)	0.0493 (11)	0.0118 (10)	−0.0048 (10)	0.0090 (9)
S1	0.0577 (5)	0.0596 (4)	0.0502 (4)	0.0164 (4)	0.0034 (4)	−0.0093 (4)
S2	0.0447 (4)	0.0593 (4)	0.0368 (3)	−0.0016 (4)	−0.0054 (3)	−0.0001 (3)
O1W	0.0518 (14)	0.0804 (17)	0.0697 (15)	0.0044 (13)	−0.0074 (13)	−0.0120 (14)
O2	0.0630 (15)	0.0595 (14)	0.0884 (19)	0.0233 (12)	−0.0160 (14)	0.0126 (14)
O3	0.0696 (17)	0.0795 (16)	0.0666 (15)	−0.0310 (14)	−0.0173 (13)	0.0333 (14)
O4	0.0704 (16)	0.0734 (16)	0.0548 (13)	−0.0134 (14)	−0.0217 (13)	0.0004 (12)
O5	0.0621 (15)	0.112 (2)	0.0614 (15)	0.0206 (16)	0.0112 (13)	−0.0203 (15)
S3	0.0382 (3)	0.0425 (3)	0.0386 (3)	0.0025 (3)	−0.0001 (3)	0.0046 (3)

Geometric parameters (Å, º)

C1—O1	1.218 (3)	C5—S2	1.819 (4)
C1—N1	1.408 (3)	C5—H5A	0.97
C1—S1	1.735 (3)	C5—H5B	0.97
C2—C3	1.491 (4)	C6—N2	1.462 (4)
C2—S1	1.791 (4)	C6—H6A	0.97
C2—H2A	0.97	C6—H6B	0.97
C2—H2B	0.97	N2—H2	0.86
C3—N1	1.464 (3)	O1W—H1W	0.85
C3—H3A	0.97	O1W—H2W	0.8494
C3—H3B	0.97	O2—S3	1.422 (2)
C4—N2	1.306 (4)	O3—S3	1.539 (2)
C4—N1	1.357 (3)	O3—H3	0.82
C4—S2	1.726 (3)	O4—S3	1.435 (2)
C5—C6	1.473 (5)	O5—S3	1.437 (3)
O1—C1—N1	123.6 (3)	H5A—C5—H5B	108.2
O1—C1—S1	125.9 (2)	N2—C6—C5	107.8 (3)
N1—C1—S1	110.6 (2)	N2—C6—H6A	110.1
C3—C2—S1	109.0 (2)	C5—C6—H6A	110.1
C3—C2—H2A	109.9	N2—C6—H6B	110.1
S1—C2—H2A	109.9	C5—C6—H6B	110.1
C3—C2—H2B	109.9	H6A—C6—H6B	108.5
S1—C2—H2B	109.9	C4—N1—C1	121.8 (2)
H2A—C2—H2B	108.3	C4—N1—C3	122.1 (2)
N1—C3—C2	108.5 (2)	C1—N1—C3	115.9 (2)
N1—C3—H3A	110	C4—N2—C6	115.9 (3)
C2—C3—H3A	110	C4—N2—H2	122.1
N1—C3—H3B	110	C6—N2—H2	122.1
C2—C3—H3B	110	C1—S1—C2	93.79 (14)
H3A—C3—H3B	108.4	C4—S2—C5	90.00 (15)
N2—C4—N1	121.2 (2)	H1W—O1W—H2W	107.7
N2—C4—S2	115.2 (2)	S3—O3—H3	109.5
N1—C4—S2	123.5 (2)	O2—S3—O4	114.16 (15)
C6—C5—S2	109.4 (2)	O2—S3—O5	111.56 (18)
C6—C5—H5A	109.8	O4—S3—O5	111.63 (17)
S2—C5—H5A	109.8	O2—S3—O3	107.84 (16)
C6—C5—H5B	109.8	O4—S3—O3	103.87 (14)
S2—C5—H5B	109.8	O5—S3—O3	107.19 (18)
S1—C2—C3—N1	−15.3 (4)	C2—C3—N1—C1	12.3 (4)
S2—C5—C6—N2	−13.4 (4)	N1—C4—N2—C6	175.9 (3)
N2—C4—N1—C1	179.4 (2)	S2—C4—N2—C6	−5.1 (4)
S2—C4—N1—C1	0.5 (3)	C5—C6—N2—C4	12.2 (4)
N2—C4—N1—C3	4.8 (4)	O1—C1—S1—C2	175.2 (3)
S2—C4—N1—C3	−174.1 (2)	N1—C1—S1—C2	−5.4 (2)
O1—C1—N1—C4	1.3 (4)	C3—C2—S1—C1	12.2 (3)
S1—C1—N1—C4	−178.19 (19)	N2—C4—S2—C5	−2.8 (2)
O1—C1—N1—C3	176.2 (3)	N1—C4—S2—C5	176.1 (2)
S1—C1—N1—C3	−3.2 (3)	C6—C5—S2—C4	9.6 (3)
C2—C3—N1—C4	−172.8 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1W···O5^i	0.85	1.92	2.755 (4)	166
N2—H2···O2	0.86	1.98	2.816 (4)	164
O1W—H2W···O5^ii	0.85	1.95	2.766 (4)	161
O3—H3···O1W	0.82	1.75	2.550 (4)	164

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