Benzo[1,2-b:4,5-b′]di­thio­phene-4,8-dione

The title mol­ecule, C₁₀H₄O₂S₂, is situated on a crystallographic center of inversion. In the crystal, weak hydrogen bonding contributes to the packing of the mol­ecules.

Related literature

This dione was synthesized according to modified literature procedures, see: Beimlung & Kossmehl (1986); Slocum & Gierer (1976). It is a precursor to many different semiconducting polymeric compounds and the structure is important in that it appears as crystalline products in poorly purified materials, see: Hundt et al. (2009); Subramaniyan et al. (2011); Yamamoto et al. (2011). For weak inter­molecular inter­actions, see: Janiak (2000); Sinnokrot et al. (2002).

Experimental

Crystal data

• C₁₀H₄O₂S₂

• M_r = 220.25

• Monoclinic, P 2₁ /n

• a = 5.6402 (5) Å

• b = 5.7745 (5) Å

• c = 13.6223 (12) Å

• β = 97.371 (1)°

• V = 440.00 (7) ų

• Z = 2

• Mo Kα radiation

• μ = 0.57 mm⁻¹

• T = 296 K

• 0.08 × 0.06 × 0.04 mm

Data collection

• Bruker APEXII diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2001) T_min = 0.955, T_max = 0.978

• 4888 measured reflections

• 1062 independent reflections

• 815 reflections with I > 2σ(I)

• R_int = 0.072

Refinement

• R[F² > 2σ(F²)] = 0.068

• wR(F²) = 0.238

• S = 1.09

• 1062 reflections

• 64 parameters

• H-atom parameters constrained

• Δρ_max = 0.78 e Å⁻³

• Δρ_min = −0.57 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C5—H5⋯O1^i	0.93	2.44	3.319 (4)	158
Symmetry code: (i) x-1, y-1, z.

Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: CrystalMaker (Palmer, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Supporting information

S1. Comment

Benzodithiophene-4,8-dione (BDTD) is a common precursor for the construction of semiconducting organic monomers. Given our interest in this field, we have isolated single crystals of this compound for structural determination. This structure is important in that it appears as crystalline products in poorly purified materials.

A thermal ellipsoid plot (Fig. 1) displays the molecular structure of the title compound.

Figure 2 shows a packing diagram of the crystal structure. Weak intermolecular interactions attribute to the packing of this compound, see: Sinnokrot et al. (2002); Janiak (2000). The closest CH···centroid distance is C1—H1···Cg1 at 3.715 (4) Å between a hydrogen atom and the center of a neighboring thiophene ring. No classic hydrogen bonds were found, but a weak hydrogen bond from C5—H5···O1 is present at 3.319 (4) Å D—A distance.

Related literature

This dione was synthesized according to modified literature procedures, see: Beimlung & Kossmehl (1986); Slocum & Gierer (1976). It is a precursor to many different semiconducting polymeric compounds, see: Hundt et al. (2009); Subramaniyan et al. (2011); Yamamoto et al. (2011). This structure is important in that it appears as crystalline products in poorly purified materials. For weak intermolecular interactions, see: Janiak (2000); Sinnokrot et al. (2002).

S2. Experimental

The title compound was prepared according to a modified literature procedure (Beimlung & Kossmehl, 1986). In a typical reaction, 2 g of 3-theonic acid was reacted with excess thionyl chloride (50 ml) at reflux temperature overnight to produce the resulting acid chloride. Upon removal of the thionyl chloride, the acid chloride was dissolved in toluene (minimum amount). The acid chloride was then added to excess diethylamine (approximately 42 ml) to produce the thiophene amide. The product was isolated in diethyl ether, concentrated, and then re-dissolved in ether (30 ml). The amide was then cyclized with excess n-butyl lithium (1.6 M in hexane, approximately 7 ml) added dropwise and allowed to stir overnight. The reaction was quenched with water, filtered, and recrystallized from glacial acetic acid in a 31–45% yield depending on reaction.

Upon isolation of the final compound, crystals suitable for X-ray diffraction were obtained from slow evaporation of approximately 20 mg of product in approximately 5 ml of chloroform. Clear, yellow block crystals formed overnight.

S3. Refinement

Crystallography. Hydrogen atom positions were placed in calculated positions and allowed to ride on the coordinates of the parent atom [C—H distances at 0.93 Å and U_iso(H)=1.2U_iso(C)].

Computing details

Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: CrystalMaker (Palmer, 2009); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. : Thermal ellipsoid plot (50% probablility) of title compound. Hydrogen atoms are omitted. Symmetry operator: i=-x + 2, -y + 1, -z + 2.
	Fig. 2. : Packing diagram of title compound down [010]. Hydrogen atoms were removed for clarity.

Benzo[1,2-b:4,5-b']dithiophene-4,8-dione

Crystal data

C10H4O2S2	F(000) = 224
Mr = 220.25	Dx = 1.662 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 5.6402 (5) Å	Cell parameters from 2545 reflections
b = 5.7745 (5) Å	θ = 6.0–55.2°
c = 13.6223 (12) Å	µ = 0.57 mm^−1
β = 97.371 (1)°	T = 296 K
V = 440.00 (7) Å^3	Prismatic block, clear yellow
Z = 2	0.08 × 0.06 × 0.04 mm

Data collection

Bruker APEXII diffractometer	1062 independent reflections
Radiation source: fine-focus sealed tube	815 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.072
Fixed Chi scans	θmax = 28.6°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	h = −7→7
Tmin = 0.955, Tmax = 0.978	k = −7→7
4888 measured reflections	l = −18→17

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)] = 0.068	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.238	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.1499P)^2 + 0.2282P] where P = (Fo^2 + 2Fc^2)/3
1062 reflections	(Δ/σ)max < 0.001
64 parameters	Δρmax = 0.78 e Å^−3
0 restraints	Δρmin = −0.57 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	0.13427 (18)	0.25931 (18)	0.81226 (8)	0.0558 (5)
O1	0.3782 (5)	0.6780 (5)	0.9199 (2)	0.0540 (8)
C1	−0.0936 (7)	0.0712 (6)	0.8176 (3)	0.0517 (9)
H1	−0.1261	−0.0467	0.7714	0.062*
C2	0.0689 (6)	0.3977 (5)	0.9156 (2)	0.0379 (7)
C3	0.2074 (6)	0.5981 (5)	0.9569 (2)	0.0390 (8)
C4	−0.1243 (5)	0.3053 (5)	0.9539 (2)	0.0366 (7)
C5	−0.2363 (6)	0.1035 (5)	0.8983 (2)	0.0421 (8)
H5	−0.3675	0.0174	0.9120	0.050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0531 (8)	0.0612 (8)	0.0549 (8)	−0.0008 (4)	0.0137 (5)	−0.0091 (4)
O1	0.0442 (14)	0.0666 (17)	0.0540 (15)	−0.0147 (12)	0.0175 (11)	0.0106 (13)
C1	0.0493 (19)	0.0468 (19)	0.058 (2)	−0.0021 (15)	0.0037 (16)	−0.0143 (16)
C2	0.0371 (15)	0.0388 (16)	0.0384 (15)	0.0010 (12)	0.0079 (12)	0.0028 (12)
C3	0.0345 (15)	0.0416 (16)	0.0413 (16)	−0.0041 (13)	0.0066 (12)	0.0096 (13)
C4	0.0339 (16)	0.0348 (15)	0.0406 (17)	−0.0034 (12)	0.0037 (13)	0.0043 (12)
C5	0.0534 (19)	0.0295 (14)	0.0394 (16)	0.0089 (13)	−0.0091 (14)	−0.0053 (12)

Geometric parameters (Å, º)

S1—C1	1.691 (4)	C2—C3	1.467 (5)
S1—C2	1.700 (3)	C3—C4^i	1.468 (5)
O1—C3	1.232 (4)	C4—C3^i	1.468 (5)
C1—C5	1.455 (5)	C4—C5	1.486 (4)
C1—H1	0.9300	C5—H5	0.9300
C2—C4	1.374 (4)
C1—S1—C2	91.10 (17)	O1—C3—C4^i	123.0 (3)
C5—C1—S1	116.6 (3)	C2—C3—C4^i	114.0 (3)
C5—C1—H1	121.7	C2—C4—C3^i	121.3 (3)
S1—C1—H1	121.7	C2—C4—C5	114.7 (3)
C4—C2—C3	124.7 (3)	C3^i—C4—C5	124.0 (3)
C4—C2—S1	113.5 (3)	C1—C5—C4	104.2 (3)
C3—C2—S1	121.8 (2)	C1—C5—H5	127.9
O1—C3—C2	123.0 (3)	C4—C5—H5	127.9

Symmetry code: (i) −x, −y+1, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5···O1^ii	0.93	2.44	3.319 (4)	158

Symmetry code: (ii) x−1, y−1, z.