4-Thioxo-3,5-dithia-1,7-hepta­nedioic acid

Abstract

The complete molecule of the title compound, C₅H₆O₄S₃, is generated by crystallographic twofold symmetry with the C=S group lying on the rotation axis. The molecules are linked through weak hydrogen-bond contacts by glide-plane operations to form R ₂ ²(20) rings and ladder-like C(4) chains along the c axis.

Related literature

For related literature, see: Bernstein et al. (1995 ▶); El-Bindary et al. (1994 ▶); Ng (1995 ▶); Reid (1962 ▶); Strube (1963 ▶).

Experimental

Crystal data

• C₅H₆O₄S₃

• M _r = 226.28

• Monoclinic,

• a = 18.899 (14) Å

• b = 5.965 (4) Å

• c = 7.565 (6) Å

• β = 92.992 (2)°

• V = 851.7 (11) ų

• Z = 4

• Mo Kα radiation

• μ = 0.84 mm⁻¹

• T = 293 (2) K

• 0.15 × 0.12 × 0.08 mm

Data collection

• Rigaku Mercury CCD diffractometer

• Absorption correction: multi-scan (CrystalClear; Rigaku, 2002 ▶) T _min = 0.912, T _max = 1.000 (expected range = 0.853–0.935)

• 2955 measured reflections

• 967 independent reflections

• 868 reflections with I > 2σ(I)

• R _int = 0.021

Refinement

• R[F ² > 2σ(F ²)] = 0.035

• wR(F ²) = 0.120

• S = 1.00

• 967 reflections

• 56 parameters

• H-atom parameters constrained

• Δρ_max = 0.45 e Å⁻³

• Δρ_min = −0.30 e Å⁻³

Data collection: CrystalClear (Rigaku, 2002 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1A⋯O2i	0.82	1.82	2.631 (3)	168

Symmetry code: (i) .

supplementary crystallographic information

Comment

Although the synthesis and the molecular structure of the title compound, also named as trithiocarbodiglycolic acid (TTCD), have been reported, to our knowledge, there is no report on the unit-cell parameters and the crystal structure of TTCD in the literature (Reid, 1962; Strube, 1963; El-Bindary et al., 1994). The crystal structure of a 1:1:1 cocrystal of TTCD and trithiocarbodiglycolate and bis(dicyclohexylammonium) (Ng, 1995) have been reported.

The molecule of the title compound occupies a crystallographic twofold rotation axis with one half-molecule in the asymmetric unit, the C₂ axis running through the C═S group (Fig. 1). The same molecular symmetry can be observed for the trithiocarbodiglycolate^2- and the neutral TTCD molecules in the structure reported by Ng (1995), which crystallises in space group P2/a. Bond distances and angles (Table 1) are close to those in the complexes composed of TTCD reported in the literature (Ng, 1995).

The molecules are linked through weak hydrogen-bond contacts (Table 2) by glide-plane operations to form R₂²(20) rings and C(4) chains along the c axis (Fig. 2).

Experimental

A mixture of trithiocarbodiglycolic acid (0.25 mmol), CoCl₂.6H₂O (0.25 mmol) was dissolved in a 10 ml water in order to synthesize the Co complexes with trithiocarbodiglycolic acid as the ligand. After stirring for about 8 h, the mixed solution was filtered. The filtrate was allowed to stand at room temperature. Colorless crystals of the title complex but not the Co complex with the trithiocarbodiglycolic acid as the ligand were obtained over a period of 10 d.

Refinement

H atoms were allowed to ride on their respective parent atoms with C—H and O—H distances of 0.97 and 0.82 Å, respectively, and were included in the refinement with isotropic displacement parameters U_iso(H) = 1.2U_eq (C) and U_iso(H) = 1.5U_eq(O), respectively.

Figures

Fig. 1.

A view of the molecule structure in the title compound, showing 30% displacement ellipsoids for non-H atoms. Symmetry code, i: 1 - x, y, 1/2 - z.

Fig. 2.

A view of the 1-D chain of the title compound along the c direction. Dashed lines represent the hydrogen bonds.

Crystal data

C5H6O4S3	F(000) = 464
Mr = 226.28	Dx = 1.765 Mg m−3
Monoclinic, C2/c	Melting point: not measured K
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 18.899 (14) Å	Cell parameters from 24 reflections
b = 5.965 (4) Å	θ = 3.6–27.4°
c = 7.565 (6) Å	µ = 0.84 mm−1
β = 92.992 (2)°	T = 293 K
V = 851.7 (11) Å3	Prism, colourless
Z = 4	0.15 × 0.12 × 0.08 mm

Data collection

Rigaku Mercury CCD diffractometer	967 independent reflections
Radiation source: rotating-anode generator	868 reflections with I > 2σ(I)
graphite	Rint = 0.021
ω scans	θmax = 27.4°, θmin = 3.6°
Absorption correction: multi-scan (CrystalClear; Rigaku, 2002)	h = −24→19
Tmin = 0.912, Tmax = 1.000	k = −7→7
2955 measured reflections	l = −9→9

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.120	H-atom parameters constrained
S = 1.00	w = 1/[σ2(Fo2) + (0.095P)2] where P = (Fo2 + 2Fc2)/3
967 reflections	(Δ/σ)max = 0.001
56 parameters	Δρmax = 0.45 e Å−3
0 restraints	Δρmin = −0.31 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
S1	0.5000	0.03720 (12)	0.2500	0.0393 (3)
S2	0.43050 (3)	0.48194 (8)	0.31113 (7)	0.0294 (2)
O1	0.29989 (9)	−0.0371 (2)	0.2569 (2)	0.0384 (4)
H1A	0.3130	−0.0788	0.3566	0.058*
O2	0.32991 (7)	0.2197 (2)	0.06832 (17)	0.0343 (4)
C1	0.5000	0.3111 (4)	0.2500	0.0247 (6)
C2	0.36648 (10)	0.2799 (3)	0.3739 (2)	0.0301 (5)
H2A	0.3895	0.1737	0.4552	0.036*
H2B	0.3300	0.3562	0.4365	0.036*
C3	0.33171 (9)	0.1520 (3)	0.2204 (2)	0.0282 (4)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
S1	0.0395 (5)	0.0202 (4)	0.0581 (6)	0.000	0.0010 (4)	0.000
S2	0.0287 (4)	0.0241 (3)	0.0358 (4)	−0.00075 (17)	0.0046 (2)	−0.00350 (18)
O1	0.0469 (10)	0.0370 (9)	0.0304 (8)	−0.0136 (7)	−0.0073 (7)	0.0040 (6)
O2	0.0414 (8)	0.0352 (8)	0.0260 (8)	−0.0019 (6)	−0.0006 (6)	0.0023 (6)
C1	0.0298 (13)	0.0225 (12)	0.0213 (13)	0.000	−0.0033 (10)	0.000
C2	0.0319 (10)	0.0343 (10)	0.0244 (10)	−0.0068 (8)	0.0033 (7)	−0.0038 (8)
C3	0.0258 (9)	0.0295 (9)	0.0293 (10)	0.0010 (8)	0.0006 (7)	−0.0019 (8)

Geometric parameters (Å, °)

S1—C1	1.634 (3)	O2—C3	1.219 (2)
S2—C1	1.7438 (18)	C2—C3	1.510 (3)
S2—C2	1.789 (2)	C2—H2A	0.9700
O1—C3	1.314 (2)	C2—H2B	0.9700
O1—H1A	0.8200
C1—S2—C2	101.88 (11)	S2—C2—H2A	108.7
C3—O1—H1A	109.5	C3—C2—H2B	108.7
S1—C1—S2i	125.75 (7)	S2—C2—H2B	108.7
S1—C1—S2	125.75 (7)	H2A—C2—H2B	107.6
S2i—C1—S2	108.50 (15)	O2—C3—O1	119.50 (18)
C3—C2—S2	114.18 (15)	O2—C3—C2	123.21 (19)
C3—C2—H2A	108.7	O1—C3—C2	117.24 (17)

Symmetry codes: (i) −x+1, y, −z+1/2.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···O2ii	0.82	1.82	2.631 (3)	168.

Symmetry codes: (ii) x, −y, z+1/2.