Redetermination of tetra-methyl tetra-thia-fulvalene-2,3,6,7-tetra-carboxyl-ate.

An improved crystal structure of the title compound, C(14)H(12)O(8)S(4), is reported. The structure, previously solved using the heavy-atom method (R = 7.1%), has now been solved using direct methods. Due to the improved quality of the data set an R value of 2.06% could be achieved. In the crystal, C-H⋯S and C-H⋯O contacts link the mol-ecules.

Related literature

For the first structure determination of the title compound, see: Belsky & Voet (1976 ▶). For a previously reported experimental procedure and physical data, see: Yoneda et al. (1978 ▶). For C—H⋯O hydrogen bonds, see: Desiraju & Steiner (1999 ▶); Katzsch et al. (2011 ▶); Fischer et al. (2011 ▶). For C—H⋯S hydrogen bonds, see: Mata et al. (2010 ▶); Novoa et al. (1995 ▶); Lu et al. (2005 ▶); Saad et al. (2010 ▶). For a description of ring motifs, see: Bernstein et al. (1995 ▶); Petersen et al. (2007 ▶). For several steps of the synthetic procedure, see: Degani et al. (1986 ▶); O’Connor & Jones (1970 ▶); Nguyen et al. (2010 ▶). For general background to the electroconductive behaviour of tetra­thia­fulvalene derivatives, see: Takase et al. (2011 ▶).

Experimental

Crystal data

C14H12O8S4

M = 436.48

Triclinic,

a = 6.8666 (2) Å

b = 7.8783 (2) Å

c = 8.4335 (2) Å

α = 100.221 (1)°

β = 99.255 (1)°

γ = 99.328 (1)°

V = 434.53 (2) Å3

Z = 1

Mo Kα radiation

μ = 0.59 mm−1

T = 100 K

0.64 × 0.16 × 0.15 mm

Data collection

Bruker APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T min = 0.705, T max = 0.917

10884 measured reflections

1534 independent reflections

1471 reflections with I > 2σ(I)

R int = 0.021

Refinement

R[F 2 > 2σ(F 2)] = 0.021

wR(F 2) = 0.055

S = 1.08

1534 reflections

120 parameters

H-atom parameters constrained

Δρmax = 0.25 e Å−3

Δρmin = −0.23 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812029534/im2387sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812029534/im2387Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812029534/im2387Isup3.cml

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

C14H12O8S4	Z = 1
Mr = 436.48	F(000) = 224
Triclinic, P1	Dx = 1.668 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.8666 (2) Å	Cell parameters from 9962 reflections
b = 7.8783 (2) Å	θ = 2.5–45.3°
c = 8.4335 (2) Å	µ = 0.59 mm−1
α = 100.221 (1)°	T = 100 K
β = 99.255 (1)°	Needle, red
γ = 99.328 (1)°	0.64 × 0.16 × 0.15 mm
V = 434.53 (2) Å3

Bruker APEXII CCD area-detector diffractometer	1534 independent reflections
Radiation source: fine-focus sealed tube	1471 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
phi and ω scans	θmax = 25.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −7→8
Tmin = 0.705, Tmax = 0.917	k = −9→9
10884 measured reflections	l = −10→10

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)] = 0.021	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.055	H-atom parameters constrained
S = 1.08	w = 1/[σ2(Fo2) + (0.0273P)2 + 0.222P] where P = (Fo2 + 2Fc2)/3
1534 reflections	(Δ/σ)max = 0.026
120 parameters	Δρmax = 0.25 e Å−3
0 restraints	Δρmin = −0.23 e Å−3

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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.

	x	y	z	Uiso*/Ueq
S1	0.30978 (5)	0.63798 (4)	1.10656 (4)	0.01479 (11)
S2	0.06589 (5)	0.56717 (4)	0.76932 (4)	0.01637 (11)
O1	0.69629 (14)	0.93615 (13)	0.94082 (12)	0.0194 (2)
O2	0.72198 (13)	0.79160 (12)	1.14884 (11)	0.0167 (2)
O3	0.27914 (16)	0.78034 (15)	0.55357 (13)	0.0265 (3)
O4	0.56544 (14)	0.69314 (13)	0.64417 (11)	0.0181 (2)
C1	0.0779 (2)	0.54255 (17)	0.97428 (16)	0.0140 (3)
C2	0.4249 (2)	0.71176 (17)	0.95464 (16)	0.0131 (3)
C3	0.31610 (19)	0.67605 (17)	0.80137 (16)	0.0138 (3)
C4	0.62881 (19)	0.82552 (17)	1.00955 (16)	0.0138 (3)
C5	0.9200 (2)	0.90095 (19)	1.21844 (18)	0.0196 (3)
H5A	1.0006	0.8996	1.1353	0.029*
H5B	0.9840	0.8560	1.3075	0.029*
H5C	0.9061	1.0194	1.2584	0.029*
C6	0.3832 (2)	0.72501 (17)	0.65299 (16)	0.0153 (3)
C7	0.6552 (2)	0.7573 (2)	0.51653 (17)	0.0226 (3)
H7A	0.5790	0.6946	0.4108	0.034*
H7B	0.7911	0.7391	0.5270	0.034*
H7C	0.6548	0.8805	0.5272	0.034*

	U11	U22	U33	U12	U13	U23
S1	0.01005 (18)	0.02032 (19)	0.01379 (18)	−0.00123 (13)	0.00238 (12)	0.00683 (13)
S2	0.01129 (18)	0.02217 (19)	0.01518 (18)	−0.00117 (13)	0.00129 (13)	0.00788 (13)
O1	0.0162 (5)	0.0197 (5)	0.0233 (5)	−0.0007 (4)	0.0067 (4)	0.0087 (4)
O2	0.0108 (5)	0.0206 (5)	0.0168 (5)	−0.0020 (4)	0.0011 (4)	0.0055 (4)
O3	0.0216 (6)	0.0423 (7)	0.0225 (5)	0.0111 (5)	0.0064 (4)	0.0184 (5)
O4	0.0158 (5)	0.0265 (5)	0.0161 (5)	0.0054 (4)	0.0076 (4)	0.0096 (4)
C1	0.0116 (6)	0.0158 (6)	0.0147 (6)	0.0017 (5)	0.0017 (5)	0.0049 (5)
C2	0.0127 (6)	0.0131 (6)	0.0160 (6)	0.0035 (5)	0.0064 (5)	0.0053 (5)
C3	0.0109 (6)	0.0133 (6)	0.0184 (7)	0.0019 (5)	0.0046 (5)	0.0050 (5)
C4	0.0126 (6)	0.0143 (6)	0.0157 (6)	0.0035 (5)	0.0062 (5)	0.0022 (5)
C5	0.0104 (7)	0.0216 (7)	0.0231 (7)	−0.0023 (5)	0.0002 (5)	0.0024 (6)
C6	0.0154 (7)	0.0147 (6)	0.0152 (7)	0.0009 (5)	0.0032 (5)	0.0032 (5)
C7	0.0188 (7)	0.0342 (8)	0.0176 (7)	0.0022 (6)	0.0087 (6)	0.0110 (6)

S1—C2	1.7452 (13)	C1—C1i	1.343 (3)
S1—C1	1.7570 (13)	C2—C3	1.3419 (19)
S2—C3	1.7468 (13)	C2—C4	1.4882 (18)
S2—C1	1.7636 (13)	C3—C6	1.4921 (18)
O1—C4	1.2022 (16)	C5—H5A	0.9600
O2—C4	1.3363 (16)	C5—H5B	0.9600
O2—C5	1.4559 (16)	C5—H5C	0.9600
O3—C6	1.2007 (17)	C7—H7A	0.9600
O4—C6	1.3263 (16)	C7—H7B	0.9600
O4—C7	1.4487 (16)	C7—H7C	0.9600
C2—S1—C1	94.90 (6)	O2—C5—H5A	109.5
C3—S2—C1	94.65 (6)	O2—C5—H5B	109.5
C4—O2—C5	115.25 (10)	H5A—C5—H5B	109.5
C6—O4—C7	115.57 (11)	O2—C5—H5C	109.5
C1i—C1—S1	122.42 (14)	H5A—C5—H5C	109.5
C1i—C1—S2	122.68 (14)	H5B—C5—H5C	109.5
S1—C1—S2	114.90 (7)	O3—C6—O4	125.74 (12)
C3—C2—C4	125.13 (12)	O3—C6—C3	122.87 (12)
C3—C2—S1	117.68 (10)	O4—C6—C3	111.34 (11)
C4—C2—S1	116.86 (10)	O4—C7—H7A	109.5
C2—C3—C6	126.96 (12)	O4—C7—H7B	109.5
C2—C3—S2	117.78 (10)	H7A—C7—H7B	109.5
C6—C3—S2	115.23 (10)	O4—C7—H7C	109.5
O1—C4—O2	125.14 (12)	H7A—C7—H7C	109.5
O1—C4—C2	124.48 (12)	H7B—C7—H7C	109.5
O2—C4—C2	110.33 (11)
C2—S1—C1—C1i	178.58 (16)	C5—O2—C4—O1	0.21 (18)
C2—S1—C1—S2	−1.44 (8)	C5—O2—C4—C2	−177.38 (10)
C3—S2—C1—C1i	−177.53 (16)	C3—C2—C4—O1	22.1 (2)
C3—S2—C1—S1	2.49 (8)	S1—C2—C4—O1	−151.10 (11)
C1—S1—C2—C3	−0.67 (11)	C3—C2—C4—O2	−160.29 (12)
C1—S1—C2—C4	173.05 (10)	S1—C2—C4—O2	26.51 (14)
C4—C2—C3—C6	7.2 (2)	C7—O4—C6—O3	10.1 (2)
S1—C2—C3—C6	−179.69 (10)	C7—O4—C6—C3	−172.26 (11)
C4—C2—C3—S2	−170.52 (10)	C2—C3—C6—O3	−137.60 (15)
S1—C2—C3—S2	2.63 (15)	S2—C3—C6—O3	40.13 (17)
C1—S2—C3—C2	−3.06 (11)	C2—C3—C6—O4	44.73 (18)
C1—S2—C3—C6	178.99 (10)	S2—C3—C6—O4	−137.54 (10)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7A···S1ii	0.96	2.83	3.735 (2)	158
C5—H5A···O1iii	0.96	2.50	3.324 (2)	143
C5—H5C···O3iv	0.96	2.65	3.481 (2)	145

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7A⋯S1i	0.96	2.83	3.735 (2)	158
C5—H5A⋯O1ii	0.96	2.50	3.324 (2)	143
C5—H5C⋯O3iii	0.96	2.65	3.481 (2)	145

Symmetry codes: (i) ; (ii) ; (iii) .