5-(4,5-Ethyl­enedithio-1,3-dithiol-2-yl­idene)-1,3,4,6-tetra­thia­penta­len-2-one (EDTO-TTP) and 5-[4,5-(ethene-1,2-di­yldithio)-1,3-dithiol-2-yl­idene]-1,3,4,6-tetra­thia­penta­len-2-one (VDTO-TTP)

The title sulfur-rich organic mol­ecular crystals, namely EDTO-TTP (C₉H₄OS₈) and VDTO-TTP (C₉H₂OS₈), are characterized by conjugated C-S bonds and S...S inter­molecular short contacts. The planar EDTO-TTP mol­ecules are parallel packed and exhibit strong inter­molecular inter­actions, including side-by-side transverse S...S contacts, face-to-face longitudinal [pi]-[pi] inter­actions and C-H...O hydrogen bonding. On cooling the EDTO-TTP crystal from 220 to 120 K, the cell dimensions and the inter­molecular distances (such as S...S contacts and especially [pi]-[pi] spacings) become shorter, while the intra­molecular bonds become longer. The curved VDTO-TTP mol­ecules are packed in such a way as to make the crystal fully depolarized. The inter­molecular inter­actions of the VDTO-TTP crystal are relatively weak, because of the weak [pi]-[pi] inter­actions and the lack of hydrogen bonding.

S1. Comment

Chalcogen-rich electronic donors have been playing a central role in the field of molecular conductors. Except for several alkali metal salts of C₆₀, all the reported organic charge-transfer superconductors belong to the chalcogen-rich type. In fact chalcogen-rich donors have more important applications, for example, as single component molecular conductors (Ashizawa et al., 2004) or as organic field-effect transistors in the field of semi-conductors. Some tetrathiafulvalene (TTF) derivatives were recently reported to have a very high field-effect mobility, which can well match the mobility of the silicon-based inorganic field-effect transistors (Mass-Torrent et al., 2004). It is well known that the basic structural necessity for molecular conductors and semi-conductors is the existence of strong intermolecular interactions in the crystals.

For a long time, TTF and its derivative bis(ethylenedithio)tetrathiafulvalene (BEDT–TTF) have been regarded as the most dominant electronic donors (Williams et al., 1992). In recent years, a new multi-sulfur moiety, 1,3,4,6-tetrathiapentalene (TTP) has received intense attention, and various TTP-based novel electronic donors have been synthesized. Several 2,5-bis(1,3-dithian-2-ylidene)-1,3,4,6-tetrathiapentalene (BDA–TTP) based charge-transfer salts, among other TTP derivatives, have been reported to exhibit superconductivity (Misaki et al., 1993; Yamada et al., 1999; Yamada et al., 2001). Our strategy in exploring new molecular conductors is to combine structural factors of TTF and TTP together. With this idea in mind, we synthesized the title compounds (namely EDTO–TTP and VDTO–TTP) and determined their X-ray structures. The synthesis of EDTO–TTP was once briefly mentioned by Mori et al. (1998), but no details of the synthesis or the crystal structure have been reported. We report here the structure at 220 K, (I), and 120 K, (II). VDTO–TTP, (III), is a new compound.

In (I) and (II), the EDTO–TTP molecule takes a planar conformation. Except for the terminal –CH₂—CH₂– ethylene group, all the other atoms are perfectly coplanar, and the least-squares plane based on these atoms is defined as the molecular plane hereafter (see Fig. 1). In (III), the curved VDTO–TTP molecule looks like a wingless jet with its terminal –CH═CH– vinylene group being the empennage (see Fig. 2). Atoms O1, C1, C2, C3, S1, S2, S3 and S4 (plane 1), atoms C6, C7, S5, S6, S7 and S8 (plane 2) and the empennage atoms (C8, C9, S7, S8, H8 and H9; plane 3) form three separate planes, the dihedral angles being 26.6 (1)° (between planes 1 and 2) and 53.3 (1)° (planes 2 and 3).

As shown in Tables 1 and 3, the bond characteristics of (I) and (II) are the same. Any non-H bond of (II) is slightly longer than its corresponding bond in (I), i.e. the EDTO–TTP molecule appears larger at low temperature. Thus, when discussing general bond characteristics below, structure (II) is not discussed unless (I) and (II) are being compared. For the three structures, all the C—S bonds, except the two terminal C—S single bonds in (I), lie between the single C—S and double C═S bonds, showing the π-conjugated nature of these molecules. The terminal S7—C9 and S8—C8 bonds in (I), involving the ethylene group, are single bonds with an average length of 1.796 (3) Å. The average of the S7—C9 and S8—C8 bond lengths [1.764 (2) Å] in (III), however, is obviously shorter than its counterpart in (I) because of the influence of the vinylene group. Three C═C bonds in the TTF moiety and the C═O bond are double bonds. Owing to the influence of the neighbouring C═O bond, the C1—S1 and C1—S2 bonds are the longest π-conjugated C—S bonds, while C2—S2 and C3—S1 are the shortest. The single C8—C9 bond [1.475 (4) Å] in terminal ethylene group in (I) and the double C8═C9 bond [1.309 (3) Å] in the vinylene group in (III) have been confirmed.

The planar EDTO–TTP molecules pack as parallel layers. As shown in Fig. 3, all the molecular planes can be indexed as (-105); they lie parallel to the b axis and roughly perpendicular to the c axis [87.04 (1)°]. In a molecular layer, the sum of the molecular dipole moments is along the +b direction. In a neighbouring molecular layer, however, the sum of the dipole moments is along the opposite, -b, direction, causing the polarization of the crystal to vanishing. There are several transverse short intermolecular S···S and S···O contacts between neighbouring molecules. In (I), for example, the S6···S7(x - 1, y, z), S8···S7(x - 1, y, z) and S8···O1(-x + 1/2, y - 1/2, -z + 3/2) distances are 3.470 (1), 3.396 (1) and 3.225 (2) Å, respectively. At low temperature in (II), these contacts have shortened to 3.443 (1), 3.377 (1) and 3.216 (2) Å, respectively. Along the c-axis direction, molecules are face-to-face overlapped, forming eclipsed molecular columns or stacks (see Fig. 4). The alternate spacings of the neighbouring molecular planes in the one-dimensional stacks are 3.540 (3) and 3.601 (3) Å in (I), and 3.507 (3) and 3.561 (3) Å in (II), showing the much enhanced π–π longitudinal intermolecular interactions at low temperature. The average thermal expansion coefficients are α_a = 2.9 × 10 ^-5 K^-1, α_b = -0.90 × 10 ^-5 K^-1 and α_c = 10.0 × 10^-5 K-¹. The high anisotropy of the thermal expansion and the large α_c value indicate that the π-stack direction is more condensable and has more potential to strengthen π–π interactions. Moreover there are four C—H···O hydrogen bonds: the two stronger bonds, C8—H81···O1(-x + 1, -y + 1, -z + 2) and C9—H92···O1(-x + 1, -y + 1, –z+1), are longitudinal and the the other two are transverse (see Fig. 4 and Table 2). Again, the hydrogen bonds in (II) are stronger than those in (I). It is thus revealed that, when cooling the EDTO–TTP crystal, the cell dimensions and the intermolecular distances become shorter, while the intramolecular bonds become longer.

The packing of the curved molecule of (III) shows some differences from the packing of the planar EDTO–TTP molecule. If a pencil-like molecule is put into a `pencil box', the dipolar molecule has two ways of packing: head-to-tail [the case of the longitudinal face-to-face neighbourhood of (I)] or head-to-head [the transverse side-by-side neighbourhood of (I)]. The curved `pencil' of molecule (III), however, has four ways of arranging: head-right, head-left, curve-up and curve-down. As shown in Fig. 5, among the four neighbours of a molecule of (III), none of its neighbours takes the same way of arranging with the central molecule. In another word, crystal (III) is fully depolarized. Although crystals (I) is also centrosymmetric, it is not fully depolarized. There are also strong transverse S···S and S···O intermolecular short contacts in (III), characterized by the lengths of 3.431 (1) for S6···S7(-x + 1/2, y - 1/2, z), 3.400 (1) for S8···S7(-x + 1/2, y - 1/2, z), and 3.052 (2) for O1···S8(-x + 1/2, -y + 1, z + 1/2) (Fig. 6). However, the π–π interactions in (III) are relatively weak, since the overlap of the two face-to-face molecules is staggered rather than eclipsed and the planarity of the molecule is poor. Most distinguishingly, there are no hydrogen bonds in (III). Thus the intermolecular interactions of (III) should be weaker than that of (I).

Above all, the EDTO–TTP crystal exhibits strong intermolecular interactions, including transverse S···S interactions, longitudinal π–π interactions and hydrogen bonding. We believe that these strong intermolecular interactions may endow it with some applications in the semi-conductor field.

Related literature

For related literature, see: Ashizawa et al. (2004); Mori et al. (1998); Xue et al. (2004); Yamada et al. (2001).

S2. Experimental

For the synthesis of VDTO–TTP, 2,3-bis(2-cyanoethylthio)-6,7-vinylenedithiotetrathiafulvalene (Xue et al., 2004) (0.35 g, 0.76 mmol) was dissolved in acetone (30 ml) and excess CsOH.H₂O (0.78 g, 4.6 mmol) was added in the presence of N₂ at room temperature. Stirring was continued for 4 h at room temperature. Zinc chloride (0.42 g, 3.5 mmol) was added to the orange reaction mixture, followed by Bu₄NBr (0.68 g, 2.1 mmol) under N₂. After 2 h, the reaction mixture was dried in vacuo. The residue was suspended in tetrahydrofuran (30 ml) and then an excess of triphosgen (0.55 g, 1.9 mmol) at 195 K was added under the protection of N₂. The solution was stirred overnight. An orange precipitate was obtained and dried in vacuo. The precipitate was dissolved in carbon disulfide, washed with water and dried with anhydrous magnesium sulfate. Compound (III) was isolated by silica gel column chromatography using carbon disulfide as eluant. Orange prism-shaped crystals were formed on slow evaporation of the carbon disulfide solvent at room temperature. IR (v, cm^-1): 3030 (w, CH), 2920 (w, CH), 1676 (vs, C═O), 1616 (m),1489 (m), 965(m), 900 (m), 875 (m), 794 (m), 750 (m), 692 (s), 682 (s), 671 (m), 407(s). EDTO–TTP was synthesized by a similar procedure. IR (v, cm^-1): 2970(w, CH₂), 2922 (w, CH₂), 1664 (vs, C═O), 1624 (vs), 1609 (vs), 1414(m), 969 (m), 881 (s), 857 (m), 766 (s), 757 (s), 409 (vs). Note that the carbonyl viboratin of EDTO–TTP has a 12 cm^-1 redshift relative to that of VDTO–TTP.

S3. Refinement

All the H atoms were located in a difference Fourier map and refined in the isotropic approximation.

Computing details

Data collection: SMART (Version 5.049; Bruker, 1998) for (I), (II); APEX2 (Bruker, 2005) for (III). Cell refinement: SAINT (Version 7.46A; Bruker, 2007) for (I), (II); APEX2 (Bruker, 2005) for (III). Data reduction: SAINT (Version 7.46A; Bruker, 2007) for (I), (II); APEX2 (Bruker, 2005) for (III). Program(s) used to solve structure: SHELXTL (Version 6.14; Sheldrick, 2008) for (I), (II); SHELXS97 (Sheldrick, 2008) for (III). Program(s) used to refine structure: SHELXTL (Version 6.14; Sheldrick, 2008) for (I), (II); SHELXL97 (Sheldrick, 2008) for (III). Molecular graphics: SHELXTL (Version 6.14; Sheldrick, 2008) for (I), (II); SHELXTL (Sheldrick, 2008) for (III). Software used to prepare material for publication: SHELXTL (Version 6.14; Sheldrick, 2008) for (I), (II); WinGX (Farrugia, 1999) for (III).

Figures

	Fig. 1. The molecular structure of (I). Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. The molecular structure of (III). Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 3. A view, along the c axis, of the crystal structure (I), showing the transverse side-by-side S···S and S···O short intermolecular contacts. [Symmetry codes: (i) -x + 1/2, y - 1/2, -z + 3/2; (v) x - 1, y, z.] The longitudinal face-to-face eclipsed π–π overlap is also displayed.
	Fig. 4. A view, along the a axis, of the crystal structure (I). Dashed lines denote intermolecular hydrogen bonds. [Symmetry codes: (i) -x + 1/2, y - 1/2, -z + 3/2; (ii) -x + 1, -y + 1, -z + 2; (iii) -x + 1, -y + 1, -z + 1; (iv) -x + 3/2, y - 1/2, -z + 3/2.]
	Fig. 5. The neighbourhood of a molecule of (III), showing that none of its neighbours takes the same orientation as it. Thus (III) is fully depolarized.
	Fig. 6. The packing of molecule (III). Dashed lines denote intermolecular S···S and S···O short contacts. [Symmetry codes: (i) -x + 1/2, y - 1/2, z; (ii) -x + 1/2, -y + 1, z + 1/2.]

(I) 5-(4,5-Ethylenedithio-1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalen-2-one

Crystal data

C9H4OS8	F(000) = 776
Mr = 384.60	Dx = 1.944 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 4976 reflections
a = 6.4948 (4) Å	θ = 2.8–27.1°
b = 28.7194 (16) Å	µ = 1.34 mm^−1
c = 7.1503 (4) Å	T = 220 K
β = 99.548 (1)°	Plate, orange
V = 1315.25 (13) Å^3	0.23 × 0.19 × 0.02 mm
Z = 4

Data collection

Siemens SMART 1K CCD area-detector diffractometer	2682 independent reflections
Radiation source: fine-focus sealed tube	2107 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
Detector resolution: 8 pixels mm^-1	θmax = 27.2°, θmin = 2.8°
Ω scans	h = −8→7
Absorption correction: multi-scan (SADABS 2006/1; Bruker, 2005), R(int)=0.047 before correction	k = −33→34
Tmin = 0.749, Tmax = 0.974	l = −8→9
11099 measured reflections

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)] = 0.029	Hydrogen site location: difference Fourier map
wR(F^2) = 0.064	All H-atom parameters refined
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0194P)^2 + 0.9207P] where P = (Fo^2 + 2Fc^2)/3
2682 reflections	(Δ/σ)max = 0.001
179 parameters	Δρmax = 0.54 e Å^−3
0 restraints	Δρmin = −0.32 e Å^−3

Special details

Experimental. The data collection nominally covered full sphere of reciprocal space, by a combination of 4 runs of narrow-frame ω-scans (scan width 0.3° ω, 20 s exposure), every run at a different ϕ angle. Crystal to detector distance 4.94 cm

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	0.55521 (10)	0.64008 (2)	0.76478 (9)	0.02842 (15)
S2	0.10921 (9)	0.61106 (2)	0.67531 (9)	0.02841 (15)
S3	0.68965 (9)	0.53783 (2)	0.79025 (9)	0.02792 (15)
S4	0.24090 (9)	0.50892 (2)	0.69960 (9)	0.02890 (16)
S5	0.82327 (9)	0.42849 (2)	0.81049 (9)	0.02526 (15)
S6	0.37694 (9)	0.40187 (2)	0.72496 (9)	0.02516 (15)
S7	0.98235 (9)	0.33257 (2)	0.84731 (11)	0.03497 (18)
S8	0.45355 (9)	0.30048 (2)	0.74265 (10)	0.03253 (17)
O1	0.2361 (3)	0.69816 (6)	0.7106 (3)	0.0419 (5)
C1	0.2890 (4)	0.65767 (9)	0.7160 (4)	0.0297 (6)
C2	0.2984 (4)	0.56819 (8)	0.7102 (3)	0.0237 (5)
C3	0.4996 (3)	0.58123 (8)	0.7505 (3)	0.0224 (5)
C4	0.5062 (3)	0.49208 (8)	0.7510 (3)	0.0211 (5)
C5	0.5620 (3)	0.44691 (8)	0.7616 (3)	0.0210 (5)
C6	0.5612 (3)	0.35650 (8)	0.7635 (3)	0.0221 (5)
C7	0.7634 (3)	0.36881 (8)	0.8038 (3)	0.0230 (5)
C8	0.6771 (5)	0.26441 (10)	0.8235 (6)	0.0497 (9)
H82	0.635 (4)	0.2334 (11)	0.768 (4)	0.047 (8)*
H81	0.723 (7)	0.2684 (14)	0.978 (6)	0.114 (16)*
C9	0.8722 (5)	0.27810 (10)	0.7581 (6)	0.0482 (8)
H92	0.813 (7)	0.2784 (14)	0.609 (6)	0.105 (14)*
H91	0.978 (5)	0.2573 (12)	0.811 (5)	0.071 (11)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0304 (3)	0.0158 (3)	0.0388 (4)	−0.0014 (2)	0.0048 (3)	−0.0005 (3)
S2	0.0260 (3)	0.0200 (3)	0.0385 (4)	0.0049 (2)	0.0034 (3)	0.0014 (3)
S3	0.0211 (3)	0.0167 (3)	0.0454 (4)	−0.0008 (2)	0.0039 (3)	0.0004 (3)
S4	0.0202 (3)	0.0176 (3)	0.0478 (4)	−0.0004 (2)	0.0027 (3)	0.0008 (3)
S5	0.0189 (3)	0.0177 (3)	0.0388 (4)	−0.0014 (2)	0.0034 (2)	0.0005 (2)
S6	0.0187 (3)	0.0162 (3)	0.0394 (4)	0.0001 (2)	0.0013 (2)	0.0009 (2)
S7	0.0199 (3)	0.0225 (3)	0.0616 (5)	0.0037 (2)	0.0041 (3)	0.0013 (3)
S8	0.0227 (3)	0.0157 (3)	0.0581 (4)	−0.0012 (2)	0.0038 (3)	−0.0028 (3)
O1	0.0480 (11)	0.0179 (10)	0.0611 (13)	0.0077 (8)	0.0126 (10)	0.0026 (9)
C1	0.0354 (14)	0.0211 (13)	0.0334 (14)	0.0026 (10)	0.0076 (11)	0.0025 (10)
C2	0.0248 (12)	0.0175 (12)	0.0285 (13)	0.0008 (9)	0.0041 (10)	0.0009 (10)
C3	0.0242 (12)	0.0165 (12)	0.0264 (13)	0.0017 (9)	0.0034 (10)	0.0009 (9)
C4	0.0191 (11)	0.0180 (12)	0.0262 (13)	−0.0010 (8)	0.0035 (10)	0.0001 (9)
C5	0.0210 (11)	0.0181 (12)	0.0243 (12)	−0.0015 (9)	0.0049 (9)	−0.0001 (9)
C6	0.0219 (11)	0.0159 (12)	0.0285 (13)	0.0014 (9)	0.0047 (10)	−0.0002 (9)
C7	0.0222 (11)	0.0173 (12)	0.0299 (13)	0.0014 (9)	0.0055 (10)	0.0004 (10)
C8	0.0322 (15)	0.0203 (15)	0.093 (3)	0.0010 (11)	0.0003 (16)	0.0012 (15)
C9	0.0335 (15)	0.0253 (16)	0.084 (3)	0.0082 (12)	0.0051 (16)	−0.0029 (15)

Geometric parameters (Å, º)

S1—C3	1.728 (2)	S7—C9	1.793 (3)
S1—C1	1.780 (3)	S8—C6	1.751 (2)
S2—C2	1.728 (2)	S8—C8	1.799 (3)
S2—C1	1.768 (3)	O1—C1	1.211 (3)
S3—C3	1.744 (2)	C2—C3	1.344 (3)
S3—C4	1.765 (2)	C4—C5	1.346 (3)
S4—C2	1.742 (2)	C6—C7	1.344 (3)
S4—C4	1.768 (2)	C8—C9	1.475 (4)
S5—C5	1.756 (2)	C8—H82	0.99 (3)
S5—C7	1.757 (2)	C8—H81	1.10 (4)
S6—C5	1.756 (2)	C9—H92	1.07 (4)
S6—C6	1.759 (2)	C9—H91	0.94 (3)
S7—C7	1.748 (2)
C3—S1—C1	94.53 (11)	C4—C5—S5	122.96 (17)
C2—S2—C1	94.67 (11)	S6—C5—S5	115.00 (12)
C3—S3—C4	93.73 (10)	C7—C6—S8	128.46 (18)
C2—S4—C4	93.66 (11)	C7—C6—S6	116.99 (17)
C5—S5—C7	94.94 (10)	S8—C6—S6	114.56 (12)
C5—S6—C6	95.23 (11)	C6—C7—S7	128.22 (18)
C7—S7—C9	101.04 (13)	C6—C7—S5	117.81 (17)
C6—S8—C8	102.25 (12)	S7—C7—S5	113.96 (12)
O1—C1—S2	123.1 (2)	C9—C8—S8	115.8 (2)
O1—C1—S1	122.7 (2)	C9—C8—H82	107.6 (17)
S2—C1—S1	114.27 (13)	S8—C8—H82	103.5 (16)
C3—C2—S2	118.36 (18)	C9—C8—H81	101 (2)
C3—C2—S4	118.41 (18)	S8—C8—H81	109 (2)
S2—C2—S4	123.22 (13)	H82—C8—H81	120 (3)
C2—C3—S1	118.15 (18)	C8—C9—S7	115.6 (2)
C2—C3—S3	118.19 (18)	C8—C9—H92	98 (2)
S1—C3—S3	123.64 (13)	S7—C9—H92	114 (2)
C5—C4—S3	122.69 (17)	C8—C9—H91	108 (2)
C5—C4—S4	121.31 (17)	S7—C9—H91	101 (2)
S3—C4—S4	116.00 (13)	H92—C9—H91	121 (3)
C4—C5—S6	122.03 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C8—H82···O1^i	0.99 (3)	2.64 (3)	3.266 (3)	121 (2)
C8—H81···O1^ii	1.10 (4)	2.40 (4)	3.456 (5)	161 (3)
C9—H92···O1^iii	1.07 (4)	2.35 (4)	3.378 (4)	160 (3)
C9—H91···O1^iv	0.94 (3)	2.54 (4)	3.407 (3)	153 (3)

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

(II) 5-(4,5-Ethylenedithio-1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalen-2-one

Crystal data

C9H4OS8	F(000) = 776
Mr = 384.60	Dx = 1.964 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 6877 reflections
a = 6.4762 (4) Å	θ = 2.8–28.5°
b = 28.7451 (16) Å	µ = 1.35 mm^−1
c = 7.0792 (4) Å	T = 120 K
β = 99.322 (1)°	Plate, orange
V = 1300.45 (13) Å^3	0.23 × 0.19 × 0.02 mm
Z = 4

Data collection

Siemens SMART 1K CCD area-detector diffractometer	3072 independent reflections
Radiation source: fine-focus sealed tube	2537 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
Detector resolution: 8 pixels mm^-1	θmax = 28.6°, θmin = 1.4°
Ω scans	h = −8→8
Absorption correction: multi-scan (SADABS 2006/1; Bruker, 2005), R(int)=0.046 before correction	k = −38→37
Tmin = 0.746, Tmax = 0.974	l = −9→8
12766 measured reflections

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)] = 0.029	Hydrogen site location: difference Fourier map
wR(F^2) = 0.061	All H-atom parameters refined
S = 1.10	w = 1/[σ^2(Fo^2) + (0.0194P)^2 + 0.9207P] where P = (Fo^2 + 2Fc^2)/3
3072 reflections	(Δ/σ)max = 0.001
179 parameters	Δρmax = 0.44 e Å^−3
0 restraints	Δρmin = −0.34 e Å^−3

Special details

Experimental. The data collection nominally covered full sphere of reciprocal space, by a combination of 4 runs of narrow-frame ω-scans (scan width 0.3° ω, 20 s exposure), every run at a different ϕ angle. Crystal to detector distance 4.94 cm

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	0.55521 (8)	0.640266 (17)	0.76487 (8)	0.01651 (12)
S2	0.10727 (8)	0.611130 (17)	0.67498 (8)	0.01651 (12)
S3	0.69030 (8)	0.537928 (16)	0.79101 (8)	0.01609 (12)
S4	0.23974 (8)	0.508942 (17)	0.69930 (8)	0.01651 (12)
S5	0.82440 (8)	0.428497 (16)	0.81116 (8)	0.01471 (11)
S6	0.37596 (8)	0.401928 (16)	0.72511 (8)	0.01443 (11)
S7	0.98460 (8)	0.332565 (18)	0.84717 (9)	0.02016 (13)
S8	0.45296 (8)	0.300408 (17)	0.73851 (9)	0.01901 (12)
O1	0.2343 (3)	0.69836 (5)	0.7113 (2)	0.0254 (4)
C1	0.2883 (3)	0.65784 (7)	0.7165 (3)	0.0189 (4)
C2	0.2970 (3)	0.56818 (7)	0.7098 (3)	0.0140 (4)
C3	0.4995 (3)	0.58123 (7)	0.7502 (3)	0.0138 (4)
C4	0.5061 (3)	0.49214 (7)	0.7512 (3)	0.0129 (4)
C5	0.5624 (3)	0.44699 (7)	0.7615 (3)	0.0130 (4)
C6	0.5611 (3)	0.35643 (6)	0.7623 (3)	0.0139 (4)
C7	0.7640 (3)	0.36865 (7)	0.8029 (3)	0.0150 (4)
C8	0.6768 (4)	0.26454 (8)	0.8292 (4)	0.0261 (5)
H82	0.626 (4)	0.2329 (10)	0.777 (4)	0.036 (8)*
H81	0.696 (5)	0.2667 (11)	0.979 (5)	0.063 (10)*
C9	0.8741 (4)	0.27770 (8)	0.7562 (4)	0.0253 (5)
H92	0.844 (4)	0.2794 (9)	0.615 (4)	0.036 (8)*
H91	0.984 (4)	0.2560 (10)	0.805 (4)	0.040 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0178 (3)	0.0097 (2)	0.0217 (3)	−0.00067 (18)	0.0023 (2)	−0.00041 (19)
S2	0.0155 (3)	0.0121 (2)	0.0215 (3)	0.00255 (18)	0.0015 (2)	0.00088 (19)
S3	0.0122 (3)	0.0101 (2)	0.0257 (3)	−0.00073 (18)	0.0023 (2)	0.00013 (19)
S4	0.0118 (3)	0.0110 (2)	0.0262 (3)	−0.00019 (18)	0.0016 (2)	0.0004 (2)
S5	0.0116 (2)	0.0108 (2)	0.0215 (3)	−0.00073 (17)	0.0020 (2)	0.00005 (19)
S6	0.0111 (2)	0.0098 (2)	0.0218 (3)	0.00014 (17)	0.0009 (2)	0.00035 (19)
S7	0.0116 (3)	0.0143 (3)	0.0341 (3)	0.00208 (19)	0.0020 (2)	0.0009 (2)
S8	0.0133 (3)	0.0101 (2)	0.0329 (3)	−0.00043 (18)	0.0015 (2)	−0.0013 (2)
O1	0.0281 (9)	0.0121 (7)	0.0368 (10)	0.0046 (6)	0.0074 (7)	0.0021 (7)
C1	0.0221 (12)	0.0164 (10)	0.0189 (11)	0.0019 (8)	0.0056 (9)	0.0020 (8)
C2	0.0162 (10)	0.0099 (9)	0.0156 (10)	−0.0001 (7)	0.0022 (8)	0.0007 (7)
C3	0.0149 (11)	0.0111 (9)	0.0151 (11)	0.0015 (7)	0.0017 (8)	0.0000 (7)
C4	0.0112 (10)	0.0126 (9)	0.0147 (10)	−0.0011 (7)	0.0013 (8)	0.0003 (7)
C5	0.0124 (10)	0.0135 (9)	0.0132 (10)	−0.0011 (7)	0.0025 (8)	−0.0002 (7)
C6	0.0136 (10)	0.0089 (9)	0.0189 (11)	0.0015 (7)	0.0022 (8)	−0.0013 (7)
C7	0.0151 (10)	0.0109 (9)	0.0192 (11)	0.0003 (7)	0.0037 (8)	0.0016 (8)
C8	0.0186 (12)	0.0137 (11)	0.0452 (16)	0.0013 (8)	0.0033 (11)	0.0037 (10)
C9	0.0196 (12)	0.0153 (11)	0.0402 (16)	0.0049 (9)	0.0026 (11)	−0.0028 (10)

Geometric parameters (Å, º)

S1—C3	1.735 (2)	S7—C9	1.807 (2)
S1—C1	1.780 (2)	S8—C6	1.753 (2)
S2—C2	1.731 (2)	S8—C8	1.810 (2)
S2—C1	1.775 (2)	O1—C1	1.215 (2)
S3—C3	1.745 (2)	C2—C3	1.350 (3)
S3—C4	1.768 (2)	C4—C5	1.347 (3)
S4—C2	1.742 (2)	C6—C7	1.346 (3)
S4—C4	1.772 (2)	C8—C9	1.503 (3)
S5—C5	1.758 (2)	C8—H82	1.02 (3)
S5—C7	1.763 (2)	C8—H81	1.05 (3)
S6—C5	1.761 (2)	C9—H92	0.99 (3)
S6—C6	1.765 (2)	C9—H91	0.97 (3)
S7—C7	1.752 (2)
C3—S1—C1	94.58 (10)	C4—C5—S6	121.84 (16)
C2—S2—C1	94.67 (10)	S5—C5—S6	115.05 (11)
C3—S3—C4	93.62 (9)	C7—C6—S8	128.43 (16)
C2—S4—C4	93.69 (10)	C7—C6—S6	117.05 (15)
C5—S5—C7	94.98 (9)	S8—C6—S6	114.52 (11)
C5—S6—C6	95.17 (9)	C6—C7—S7	128.56 (16)
C7—S7—C9	100.88 (10)	C6—C7—S5	117.74 (15)
C6—S8—C8	101.80 (10)	S7—C7—S5	113.69 (11)
O1—C1—S2	122.77 (18)	C9—C8—S8	114.31 (17)
O1—C1—S1	122.91 (18)	C9—C8—H82	110.1 (16)
S2—C1—S1	114.32 (11)	S8—C8—H82	100.7 (15)
C3—C2—S2	118.36 (15)	C9—C8—H81	111.3 (19)
C3—C2—S4	118.26 (16)	S8—C8—H81	106.4 (18)
S2—C2—S4	123.37 (12)	H82—C8—H81	114 (2)
C2—C3—S1	118.05 (15)	C8—C9—S7	114.01 (17)
C2—C3—S3	118.35 (15)	C8—C9—H92	108.7 (16)
S1—C3—S3	123.59 (12)	S7—C9—H92	108.6 (16)
C5—C4—S3	122.60 (16)	C8—C9—H91	109.2 (17)
C5—C4—S4	121.33 (16)	S7—C9—H91	102.2 (17)
S3—C4—S4	116.06 (11)	H92—C9—H91	114 (2)
C4—C5—S5	123.12 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C8—H82···O1^i	1.02 (3)	2.55 (3)	3.247 (3)	126 (2)
C8—H81···O1^ii	1.05 (3)	2.39 (3)	3.382 (3)	158 (3)
C9—H92···O1^iii	0.99 (3)	2.37 (3)	3.342 (3)	167 (2)
C9—H91···O1^iv	0.97 (3)	2.48 (3)	3.390 (3)	156 (2)

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

(III) 5-[4,5-(ethene-1,2-diyldithio)-1,3-dithiol-2-ylidene]-1,3,4,6-tetrathiapentalen-2-one

Crystal data

C9H2OS8	F(000) = 1536
Mr = 382.59	Dx = 1.934 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 4164 reflections
a = 7.3308 (1) Å	θ = 2.8–27.6°
b = 12.7832 (3) Å	µ = 1.34 mm^−1
c = 28.0416 (6) Å	T = 296 K
V = 2627.81 (9) Å^3	Prism, orange
Z = 8	0.26 × 0.14 × 0.10 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	3037 independent reflections
Radiation source: fine-focus sealed tube	2499 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
Detector resolution: 10.00 pixels mm^-1	θmax = 27.6°, θmin = 1.5°
phi and ω scans	h = −9→8
Absorption correction: multi-scan (APEX2; Bruker, 2005)	k = −16→15
Tmin = 0.723, Tmax = 0.881	l = −31→36
13259 measured reflections

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: difference Fourier map
wR(F^2) = 0.070	All H-atom parameters refined
S = 1.10	w = 1/[σ^2(Fo^2) + (0.0355P)^2] where P = (Fo^2 + 2Fc^2)/3
3037 reflections	(Δ/σ)max = 0.001
171 parameters	Δρmax = 0.35 e Å^−3
0 restraints	Δρmin = −0.20 e Å^−3

Special details

Experimental. Scan width 0.5° ω, Crystal to detector distance 6.02 cm

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
S6	0.17125 (7)	0.56037 (4)	0.157258 (16)	0.03599 (13)
S5	0.18475 (7)	0.78527 (4)	0.181888 (16)	0.03560 (13)
S2	0.20160 (8)	0.44062 (4)	0.372378 (18)	0.04552 (15)
S4	0.12762 (7)	0.50196 (4)	0.268638 (16)	0.03799 (13)
S3	0.17168 (7)	0.72691 (4)	0.294304 (16)	0.03699 (13)
S1	0.25268 (7)	0.66455 (4)	0.397878 (16)	0.04074 (14)
S7	0.30583 (8)	0.84719 (4)	0.083145 (17)	0.04230 (14)
S8	0.27217 (8)	0.60166 (4)	0.054395 (17)	0.04196 (14)
C9	0.1733 (3)	0.80180 (19)	0.03483 (7)	0.0467 (5)
H9	0.112 (3)	0.8484 (18)	0.0213 (8)	0.056 (7)*
C8	0.1606 (3)	0.70287 (18)	0.02319 (7)	0.0445 (5)
H8	0.084 (3)	0.6804 (17)	−0.0022 (7)	0.055 (6)*
C7	0.2563 (2)	0.74924 (14)	0.12440 (6)	0.0312 (4)
C6	0.2468 (3)	0.64740 (14)	0.11290 (6)	0.0318 (4)
C5	0.1749 (2)	0.65570 (14)	0.20241 (6)	0.0302 (4)
C4	0.1628 (2)	0.63128 (14)	0.24913 (6)	0.0298 (4)
C3	0.2032 (2)	0.63382 (15)	0.33907 (6)	0.0337 (4)
C2	0.1812 (2)	0.53272 (16)	0.32764 (6)	0.0338 (4)
C1	0.2519 (3)	0.53244 (18)	0.41809 (7)	0.0438 (5)
O1	0.2813 (3)	0.50819 (13)	0.45880 (5)	0.0667 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S6	0.0550 (3)	0.0300 (3)	0.0230 (2)	−0.0031 (2)	−0.0029 (2)	0.00213 (18)
S5	0.0521 (3)	0.0297 (3)	0.0251 (2)	0.0062 (2)	0.0017 (2)	0.00128 (18)
S2	0.0710 (4)	0.0366 (3)	0.0290 (3)	−0.0045 (2)	−0.0032 (2)	0.0087 (2)
S4	0.0557 (3)	0.0336 (3)	0.0247 (2)	−0.0076 (2)	−0.0035 (2)	0.00213 (19)
S3	0.0553 (3)	0.0314 (3)	0.0243 (2)	0.0053 (2)	−0.0008 (2)	0.00116 (18)
S1	0.0590 (3)	0.0406 (3)	0.0226 (2)	0.0035 (2)	−0.0022 (2)	−0.0014 (2)
S7	0.0631 (3)	0.0323 (3)	0.0315 (3)	−0.0047 (2)	0.0063 (2)	0.0050 (2)
S8	0.0667 (4)	0.0365 (3)	0.0227 (2)	0.0012 (2)	0.0011 (2)	−0.0015 (2)
C9	0.0615 (14)	0.0510 (14)	0.0276 (10)	0.0075 (12)	0.0005 (9)	0.0125 (10)
C8	0.0583 (14)	0.0520 (14)	0.0232 (9)	−0.0043 (11)	−0.0054 (9)	0.0071 (9)
C7	0.0391 (10)	0.0336 (10)	0.0209 (9)	0.0003 (8)	−0.0008 (8)	0.0026 (7)
C6	0.0415 (10)	0.0336 (10)	0.0204 (8)	0.0000 (8)	−0.0027 (7)	0.0030 (7)
C5	0.0379 (10)	0.0298 (9)	0.0231 (8)	0.0021 (8)	−0.0019 (7)	0.0015 (7)
C4	0.0357 (10)	0.0320 (9)	0.0217 (8)	0.0019 (8)	−0.0007 (7)	0.0010 (7)
C3	0.0427 (11)	0.0368 (10)	0.0216 (8)	0.0011 (8)	−0.0005 (7)	0.0029 (8)
C2	0.0422 (10)	0.0371 (10)	0.0220 (8)	−0.0016 (9)	−0.0026 (7)	0.0047 (8)
C1	0.0592 (13)	0.0471 (12)	0.0251 (10)	0.0061 (11)	0.0047 (9)	0.0053 (9)
O1	0.1162 (14)	0.0594 (11)	0.0245 (8)	0.0124 (10)	−0.0044 (8)	0.0099 (7)

Geometric parameters (Å, º)

S6—C6	1.7583 (18)	S7—C7	1.7430 (18)
S6—C5	1.7575 (18)	S7—C9	1.765 (2)
S5—C5	1.7549 (19)	S8—C6	1.7515 (18)
S5—C7	1.7567 (17)	S8—C8	1.763 (2)
S2—C2	1.7269 (19)	C9—C8	1.309 (3)
S2—C1	1.777 (2)	C9—H9	0.84 (2)
S4—C2	1.7455 (18)	C8—H8	0.95 (2)
S4—C4	1.7603 (18)	C7—C6	1.343 (2)
S3—C3	1.7450 (18)	C5—C4	1.350 (2)
S3—C4	1.7617 (18)	C3—C2	1.341 (3)
S1—C3	1.7337 (18)	C1—O1	1.202 (2)
S1—C1	1.781 (2)
C6—S6—C5	93.80 (9)	C7—C6—S6	117.37 (14)
C5—S5—C7	93.77 (8)	S8—C6—S6	119.01 (11)
C2—S2—C1	95.26 (9)	C4—C5—S5	122.64 (14)
C2—S4—C4	92.87 (9)	C4—C5—S6	122.54 (15)
C3—S3—C4	92.80 (9)	S5—C5—S6	114.76 (9)
C3—S1—C1	95.00 (9)	C5—C4—S4	121.91 (14)
C7—S7—C9	99.12 (10)	C5—C4—S3	122.35 (14)
C6—S8—C8	99.82 (10)	S4—C4—S3	115.69 (9)
C8—C9—S7	123.22 (18)	C2—C3—S1	118.08 (14)
C8—C9—H9	122.3 (16)	C2—C3—S3	118.00 (14)
S7—C9—H9	114.3 (16)	S1—C3—S3	123.88 (12)
C9—C8—S8	123.50 (17)	C3—C2—S2	118.23 (14)
C9—C8—H8	121.3 (13)	C3—C2—S4	118.07 (14)
S8—C8—H8	115.1 (13)	S2—C2—S4	123.68 (12)
C6—C7—S7	123.22 (14)	O1—C1—S2	123.50 (18)
C6—C7—S5	117.32 (14)	O1—C1—S1	123.08 (18)
S7—C7—S5	118.87 (11)	S2—C1—S1	113.42 (10)
C7—C6—S8	122.89 (14)
C7—S7—C9—C8	−40.3 (2)	S6—C5—C4—S3	178.52 (10)
S7—C9—C8—S8	0.6 (3)	C2—S4—C4—C5	167.20 (16)
C6—S8—C8—C9	38.6 (2)	C2—S4—C4—S3	−15.30 (11)
C9—S7—C7—C6	41.53 (19)	C3—S3—C4—C5	−166.67 (16)
C9—S7—C7—S5	−129.46 (13)	C3—S3—C4—S4	15.84 (11)
C5—S5—C7—C6	11.58 (17)	C1—S1—C3—C2	0.18 (18)
C5—S5—C7—S7	−176.90 (11)	C1—S1—C3—S3	177.61 (13)
S7—C7—C6—S8	−3.2 (3)	C4—S3—C3—C2	−10.26 (17)
S5—C7—C6—S8	167.92 (10)	C4—S3—C3—S1	172.30 (13)
S7—C7—C6—S6	−173.28 (10)	S1—C3—C2—S2	0.6 (2)
S5—C7—C6—S6	−2.2 (2)	S3—C3—C2—S2	−177.00 (10)
C8—S8—C6—C7	−37.0 (2)	S1—C3—C2—S4	178.95 (10)
C8—S8—C6—S6	132.90 (12)	S3—C3—C2—S4	1.4 (2)
C5—S6—C6—C7	−8.49 (17)	C1—S2—C2—C3	−1.01 (18)
C5—S6—C6—S8	−178.97 (12)	C1—S2—C2—S4	−179.27 (13)
C7—S5—C5—C4	165.70 (16)	C4—S4—C2—C3	8.37 (17)
C7—S5—C5—S6	−17.12 (11)	C4—S4—C2—S2	−173.37 (13)
C6—S6—C5—C4	−166.57 (16)	C2—S2—C1—O1	−179.4 (2)
C6—S6—C5—S5	16.25 (12)	C2—S2—C1—S1	1.07 (14)
S5—C5—C4—S4	172.82 (10)	C3—S1—C1—O1	179.6 (2)
S6—C5—C4—S4	−4.1 (2)	C3—S1—C1—S2	−0.84 (13)
S5—C5—C4—S3	−4.5 (2)