2-(Benzothia­zol-2-yl­sulfanyl)­acetic acid

In the title compound, C₉H₇NO₂S₂, the benzine ring is essentially co-planar with the thia­zole ring, making a dihedral angle of 0.36 (7)°. In the crystal structure, mol­ecules are linked by inter­molecular O—H...N hydrogen bonds between the carb­oxy group and the thia­zole N atom into chains along [10]. The chains are assembled into a supermolecular layer structure by thia­zole ring S...S contacts [3.5679 (7) Å].

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C)= 0.003 Å
• R factor = 0.030
• wR factor = 0.079
• Data-to-parameter ratio = 13.1

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Related literature

For a related structure, tris(2-hydroxyethyl)ammonium 3-benzothiazole-2-thiolate, see: Zhu et al. (2009). For S···S contacts in similar compounds, see: Dai et al. (1997).

S1. Experimental

A solution of benzothiazole-2-thiol (167.2 mg, 1.00 mmol) and K₂CO₃ (207.0 mg, 1.50 mmol) in CH₃OH (15 ml) was slowly added to a solution of 2-chloroacetic acid (113.4 mg, 1.20 mmol) in CH₃OH (10 ml). The resultant solution was stirred and refluxed for 20 h and then filtered. Colorless crystals suitable for X-ray diffraction were obtained in about a week by slow diffusion of diethyl ether into a dilute solution of the title compound in methanol. yield: ca 82.3% (based on benzothiazole-2-thiol).

S2. Refinement

The structure was solved using direct methods followed by Fourier synthesis. Non-H atoms were refined anisotropically. All of H atoms were placed in idealized positions (C—H = 0.93 or 0.97 Å, O—H = 0.82 Å), forced to ride on the atom to which they are bonded, and were included in the refinement in the riding-model approximation. U_iso values were set equal to 1.5U_eq(parent atom) for carboxylic H atom and to 1.2U_eq(parent atom)for all other H atoms.

Structure description

For a related structure, tris(2-hydroxyethyl)ammonium 3-benzothiazole-2-thiolate, see: Zhu et al. (2009). For S···S contacts in similar compounds, see: Dai et al. (1997).

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The structure of the title compound with 50% probability displacement ellipsoids.
	Fig. 2. Two-dimensional supramolecular layer which is connected by O—H···N [O···N 2.686 (2) Å, H···N 1.89 Å, O—H···N 165.3°, symmetry code: x + 1, -y + 3/2,z + 1/2] hydrogen bonds and S···S [S···S 3.568 Å, symmetry code: 1-x, 1-y, 1-z] contacts.

2-(Benzothiazol-2-ylsulfanyl)acetic acid

Crystal data

C9H7NO2S2	F(000) = 464
Mr = 225.28	Dx = 1.585 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2101 reflections
a = 6.0374 (5) Å	θ = 2.7–27.5°
b = 19.2450 (17) Å	µ = 0.53 mm^−1
c = 8.1250 (7) Å	T = 296 K
β = 90.419 (1)°	Block, pink
V = 944.02 (14) Å^3	0.23 × 0.21 × 0.17 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer	1695 independent reflections
Radiation source: fine-focus sealed tube	1439 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
φ and ω scans	θmax = 25.2°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −4→7
Tmin = 0.885, Tmax = 0.914	k = −22→23
4800 measured reflections	l = −9→9

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)] = 0.030	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.079	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0386P)^2 + 0.2852P] where P = (Fo^2 + 2Fc^2)/3
1695 reflections	(Δ/σ)max = 0.001
129 parameters	Δρmax = 0.25 e Å^−3
0 restraints	Δρmin = −0.16 e Å^−3

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.

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 > σ(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
C1	0.5666 (3)	0.77360 (10)	0.5938 (3)	0.0446 (5)
C2	0.4631 (3)	0.70448 (10)	0.5538 (3)	0.0424 (5)
H2A	0.4289	0.6798	0.6546	0.051*
H2B	0.5654	0.6764	0.4906	0.051*
C3	0.1497 (3)	0.63490 (9)	0.3747 (2)	0.0367 (4)
C4	−0.0451 (3)	0.55193 (10)	0.2515 (2)	0.0371 (4)
C5	0.1331 (3)	0.51163 (10)	0.3081 (2)	0.0391 (4)
C6	0.1436 (4)	0.44073 (10)	0.2773 (3)	0.0509 (5)
H6	0.2624	0.4143	0.3154	0.061*
C7	−0.0259 (4)	0.41063 (11)	0.1894 (3)	0.0556 (6)
H7	−0.0223	0.3632	0.1677	0.067*
C8	−0.2024 (4)	0.45021 (12)	0.1327 (3)	0.0531 (6)
H8	−0.3154	0.4287	0.0732	0.064*
C9	−0.2144 (3)	0.52022 (11)	0.1620 (2)	0.0458 (5)
H9	−0.3337	0.5461	0.1228	0.055*
N1	−0.0309 (3)	0.62213 (8)	0.2909 (2)	0.0396 (4)
O1	0.7348 (3)	0.76603 (7)	0.6956 (2)	0.0557 (4)
H1	0.7911	0.8041	0.7140	0.084*
O2	0.5039 (3)	0.82751 (8)	0.5396 (2)	0.0736 (5)
S1	0.21328 (9)	0.71923 (3)	0.43642 (7)	0.04900 (19)
S2	0.31920 (8)	0.56396 (2)	0.41411 (7)	0.04382 (18)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0430 (11)	0.0378 (11)	0.0528 (12)	0.0004 (9)	−0.0105 (10)	−0.0021 (9)
C2	0.0413 (11)	0.0343 (10)	0.0515 (12)	0.0031 (8)	−0.0147 (9)	0.0004 (8)
C3	0.0340 (10)	0.0336 (10)	0.0422 (11)	0.0021 (8)	−0.0077 (8)	0.0014 (8)
C4	0.0402 (10)	0.0332 (10)	0.0378 (10)	−0.0017 (8)	−0.0033 (8)	0.0011 (8)
C5	0.0420 (11)	0.0354 (10)	0.0398 (10)	0.0014 (8)	−0.0068 (9)	0.0023 (8)
C6	0.0621 (14)	0.0344 (11)	0.0560 (13)	0.0066 (9)	−0.0087 (11)	0.0005 (9)
C7	0.0772 (16)	0.0335 (11)	0.0562 (13)	−0.0083 (11)	−0.0032 (12)	−0.0042 (10)
C8	0.0589 (14)	0.0514 (13)	0.0489 (12)	−0.0166 (11)	−0.0080 (10)	−0.0046 (10)
C9	0.0410 (11)	0.0495 (12)	0.0468 (12)	−0.0027 (9)	−0.0099 (9)	0.0009 (9)
N1	0.0387 (9)	0.0344 (8)	0.0455 (9)	0.0022 (7)	−0.0121 (7)	0.0010 (7)
O1	0.0507 (9)	0.0409 (8)	0.0751 (11)	−0.0069 (7)	−0.0270 (8)	0.0023 (7)
O2	0.0777 (12)	0.0336 (9)	0.1090 (14)	−0.0015 (8)	−0.0464 (10)	0.0066 (8)
S1	0.0454 (3)	0.0309 (3)	0.0703 (4)	0.0053 (2)	−0.0231 (3)	−0.0041 (2)
S2	0.0415 (3)	0.0336 (3)	0.0560 (3)	0.00667 (19)	−0.0177 (2)	−0.0010 (2)

Geometric parameters (Å, º)

C1—O2	1.188 (2)	C4—C5	1.401 (3)
C1—O1	1.313 (2)	C5—C6	1.389 (3)
C1—C2	1.504 (3)	C5—S2	1.7332 (19)
C2—S1	1.8012 (19)	C6—C7	1.372 (3)
C2—H2A	0.9700	C6—H6	0.9300
C2—H2B	0.9700	C7—C8	1.386 (3)
C3—N1	1.304 (2)	C7—H7	0.9300
C3—S2	1.7345 (18)	C8—C9	1.370 (3)
C3—S1	1.7407 (18)	C8—H8	0.9300
C4—N1	1.391 (2)	C9—H9	0.9300
C4—C9	1.391 (3)	O1—H1	0.8200
O2—C1—O1	124.99 (19)	C4—C5—S2	109.55 (14)
O2—C1—C2	124.15 (19)	C7—C6—C5	118.3 (2)
O1—C1—C2	110.86 (17)	C7—C6—H6	120.9
C1—C2—S1	108.66 (14)	C5—C6—H6	120.9
C1—C2—H2A	110.0	C6—C7—C8	120.7 (2)
S1—C2—H2A	110.0	C6—C7—H7	119.7
C1—C2—H2B	110.0	C8—C7—H7	119.7
S1—C2—H2B	110.0	C9—C8—C7	121.6 (2)
H2A—C2—H2B	108.3	C9—C8—H8	119.2
N1—C3—S2	115.97 (14)	C7—C8—H8	119.2
N1—C3—S1	120.51 (14)	C8—C9—C4	118.9 (2)
S2—C3—S1	123.51 (11)	C8—C9—H9	120.6
N1—C4—C9	126.16 (18)	C4—C9—H9	120.6
N1—C4—C5	114.61 (16)	C3—N1—C4	110.65 (15)
C9—C4—C5	119.22 (18)	C1—O1—H1	109.5
C6—C5—C4	121.37 (18)	C3—S1—C2	100.82 (9)
C6—C5—S2	129.08 (16)	C5—S2—C3	89.21 (9)
O2—C1—C2—S1	−7.7 (3)	C5—C4—C9—C8	0.4 (3)
O1—C1—C2—S1	172.54 (15)	S2—C3—N1—C4	0.0 (2)
N1—C4—C5—C6	−179.50 (19)	S1—C3—N1—C4	178.49 (14)
C9—C4—C5—C6	−0.3 (3)	C9—C4—N1—C3	−179.45 (19)
N1—C4—C5—S2	0.5 (2)	C5—C4—N1—C3	−0.3 (2)
C9—C4—C5—S2	179.69 (15)	N1—C3—S1—C2	176.73 (16)
C4—C5—C6—C7	0.0 (3)	S2—C3—S1—C2	−4.87 (16)
S2—C5—C6—C7	−179.96 (17)	C1—C2—S1—C3	170.23 (15)
C5—C6—C7—C8	0.2 (3)	C6—C5—S2—C3	179.6 (2)
C6—C7—C8—C9	−0.1 (4)	C4—C5—S2—C3	−0.40 (15)
C7—C8—C9—C4	−0.2 (3)	N1—C3—S2—C5	0.25 (16)
N1—C4—C9—C8	179.49 (19)	S1—C3—S2—C5	−178.21 (14)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1^i	0.82	1.89	2.686 (2)	165

Symmetry code: (i) x+1, −y+3/2, z+1/2.