5-Benzyl-5-phenyl­[1,3]­di­thiolo­[4,5-d][1,3]­di­thiole-2-thione

In the title compound, C₁₇H₁₂S₅, the di­thiole ring bearing the aryl substituents assumes an envelope conformation with the maximum deviation from planarity being −0.053 Å. The phenyl and benzyl rings are twisted by 33.0 (1) and 31.1 (1)°, respectively, out of the di­thiole plane. The crystal packing is governed by short S...S interactions, with the shortest being 3.550 (2) Å.

S1. Comment

During the course of our studies to synthesize new bis(ethylenedithio)tetrathiafulvalene, BEDT-TTF or ET, (I), derivatives, radical cation salts which show electrical conductivity, and in some cases superconductivity (Williams et al., 1985), we have focused on the recently developed reactions of Lawesson's reagent (LR), (II) (Öztürk, 1996; Öztürk & Wallis, 1996), or phosphoruspentasulfide, P₄S₁₀, with 1,8-diketones (III). These reactions have proved to be an efficient route to the synthesis of substituted thiophene (IV) and 1,4-dithiin (V) heterocyclic systems, which could be useful building blocks for new BEDT-TTF derivatives.

In an attempt to synthesize 5,6-diphenyl (VI) derivative of BEDT-TTF, tetra-phenyl-1,8-diketone (VIII), which was prepared from the reaction of readily available dithiolate (VII) (Svenstrup & Becher, 1995) with desyl chloride, was treated with both LR and P₄S₁₀. In accordance with the result obtained by Lee et al. (1998), diphenylthiophene (IX), rather than diphenyldithiin (VI), was isolated when the reaction was performed with LR. Surprisingly, when the reaction was carried out with P₂S₅, under the same conditions, benzylphenyldithiole (X) ring formed along with (IX).

In the title compound, (X), except for the C4 atom, the fused heterocycle is nearly planar, with a dihedral angle between the S5/C3/C2/S4/S3 and C1/S2/C2/C3 mean planes of 3.02 (8)°. The thiole ring which bears aryl substituents deviates from planarity while atom C4 is displaced from the S5/C3/C2/S4 mean plane by 0.736 (4) Å. The puckering parameters (Cremer & Pople, 1975) of this ring are Q = 0.469 (3) Å and ϕ = 321.8 (4)°, so the dithiole ring assumes an envelope conformation. The mean bond distances in the dithiole thione ring are S═C 1.640 (4) and S—C(sp²) 1.732 (4) Å. These values are comparable with those found in the structures of both 6-(4-methoxyphenyl)thieno[2,3-d][1,3]-dithiole-2-thione (Öztürk & Wallis, 1996) and 5,6-diphenylthieno[2,3-d][1,3]dithiole-2-thione (Kaynak et al., 2000). The other dithiole ring of the fused heterocycle is affected by the presence of the phenyl and benzyl substituents. The bond lengths are quite different from those of adjacent dithiole ring; the mean bond lengths S—C(sp²) and S—C(sp³) are 1.748 (1) and 1.855 (14) Å, respectively. The shortening of the S5—C4 and C4—C5 distances versus the S4—C4 and C4—C11 bond may be described by the two short intramolecular contacts H10···S5 (2.58 Å) and H112···C6 (2.63 Å).

The substituted phenyl rings are essentially planar [maximum deviations being -0.002 (4) and -0.010 (4) Å for C8 and C14, respectively] and twisted slightly out of the plane of the fused heterocycle, with torsion angles of 175.4 (3) and 170.5 (3)° for S5—C4—C5—C6 and S4—C4—C11—C12, respectively. The dihedral angles between the phenyl groups (C5—C10 and C12—C17) and the S5/C3/C2/S4 mean plane are 33.0 (1) and 31.1 (1)°, respectively, while the dihedral angle between these two phenyl groups is 61.5 (1)°.

In the crystal, the molecules are packed in layers related by the translation [001]. The relevant S···S non-bonding contacts involved are S1···S2 (2 - x, 1/2 - y, 1/2 - z) 3.772 (2), S2···S3 (x, 1 + y, z) 3.601 (2), S3···S4 (x, -1 + y, z) 3.630 (2), S4···S5 (x, 1 + y, z) 3.550 (2) Å.

Related literature

For related literature, see: Cremer & Pople (1975); Kaynak et al. (2000); Lee et al. (1998); Svenstrup & Becher (1995); Williams et al. (1985); Öztürk (1996); Öztürk & Wallis (1996).

S2. Experimental

2-[5-(2-Oxo-1,2-diphenylethylsulfanyl)-2-thioxo-1,3-dithiol-4-ylsulfanyl]- 1,2-diphenyl-1-ethanone, (VIII). To a solution of dithiolate (VII) (0.26 g, 1 mmol) in dry ethanol (10 ml) and under nitrogen atmosphere was added dropwise desyl chloride (0.5 g, 2 mmol), the solution was then stirred at room temperature for 3 h. The yellow precipitate was filtered and washed with ethanol (5 ml), which was sufficiently pure for use in the next step, mp. 430–431 K (0.57 g, 90%). ¹H NMR (200 MHz, CDCl₃) δ 7.8 (20 H, m, Ph) 6.1 (H, s, PhCHS) 5.8 (H, s, PhCHS), m/z (EI) 587 M⁺, found C 63.65, H 3.44%; C₃₁H₂₂O₂S₅ requires C 63.48, H 3.44%.

5-Benzyl-5-phenyl[1,3]dithiolo[4,5-d][1,3]dithiole-2-thione, (X). A solution of 1,8-diketone (VIII) (1 g, 1.7 mmol) and P₄S₁₀ (0.8 g, 1.70 mmol) in dry toluene (30 ml) under nitrogen atmosphere was refluxed until the consumption of starting material, which took approximately 5 h. The solvent was then evaporated under reduced pressure and the remaining viscous material was chromatographed eluting with hexane-dichloromethane (3:1). The first fraction yielded 5,6-diphenylthieno[2,3-d][1,3]dithiole-2-thione, (IX) (0.23 g, 40%), and the second fraction was characterized as (X), mp. 401–402 K (0.17 g, 25%). ¹H NMR (200 MHz, CDCl₃) δ 7.40–7.18 (8 H, m, Ph) 6.92 (2H, d, J = 12 Hz, Ph) 3.76 (2H, s, PhCH₂), ¹³C NMR (50.32 Hz, CDCl₃) 205 (C═S), 139, 134, 130, 128.8, 128.5, 127.8, 127.6, 127, 126, 86, 51, m/z (EI) 376 M⁺, found C 54.28, H 3.21%; C₁₅H₁₂S₅ requires C 54.59, H 3.54%, UV (CH₃CN, nm) 426.

S3. Refinement

H atoms of rings were placed geometrically 0.95 Å from their parent atoms, while the positions of H111 and H112 were taken from a difference map. For all H atoms of rings, riding model was used with U_eq(H) = 1.3U_eq(C). The same model was also applied for H atoms of C11, after refining a few cycle isotropically and then fixed.

Computing details

Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1993); data reduction: MolEN (Fair, 1990); program(s) used to solve structure: Sir-MolEN; program(s) used to refine structure: LSFM (Fair, 1990); molecular graphics: ORTEPII (Johnson, 1965); software used to prepare material for publication: MolEN.

Figures

Fig. 1. ORTEPII (Johnson, 1965) drawing with the atomic numbering scheme. The displacement ellipsoids are drawn at the 30% probability level.

(X)

Crystal data

C17H12S5	Dx = 1.48 Mg m^−3
Mr = 376.62	Cu Kα radiation, λ = 1.5418 Å
Monoclinic, P21/c	Cell parameters from 25 reflections
a = 14.178 (3) Å	θ = 22.2–42.7°
b = 6.3433 (6) Å	µ = 6.23 mm^−1
c = 19.227 (3) Å	T = 295 K
β = 101.538 (15)°	Prismatic, brown
V = 1694.2 (5) Å^3	0.30 × 0.15 × 0.09 mm
Z = 4

Data collection

Enraf-Nonius CAD-4 diffractometer	Rint = 0.048
ω/2θ scans	θmax = 74.4°
Absorption correction: empirical (using intensity measurements) via ψ scans (north et al., 1968) ?	h = −17→17
Tmin = 0.171, Tmax = 0.571	k = 0→7
3891 measured reflections	l = −23→0
3448 independent reflections	3 standard reflections every 120 min
2513 reflections with I > 3σ(I)	intensity decay: 1%

Refinement

Refinement on F	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.047	w = 1/[σ^2(F) + (0.02*F)^2 + 0.85] except w = 0 if F^2 < cutoff.σ^2F , cutoff = 3.0
wR(F^2) = 0.054	(Δ/σ)max < 0.001
S = 0.95	Δρmax = 0.41 e Å^−3
2513 reflections	Δρmin = −0.45 e Å^−3
199 parameters

Special details

Experimental. The structure was determined by direct method (Sir-MolEN) and refined by full-matrix least-squares method (LSFM-MolEN). All non-H atoms were refined with anisotropic thermal parameters.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	1.16911 (7)	0.0945 (2)	0.28259 (6)	0.0696 (3)
S2	1.05511 (6)	0.4116 (2)	0.34326 (5)	0.0591 (3)
S3	1.01321 (7)	−0.0315 (2)	0.35718 (5)	0.0546 (3)
S4	0.89753 (6)	0.5290 (2)	0.42748 (5)	0.0554 (3)
S5	0.86214 (7)	0.0779 (2)	0.44768 (5)	0.0507 (2)
C1	1.0850 (3)	0.1548 (6)	0.3267 (2)	0.0524 (12)
C2	0.9655 (2)	0.3491 (6)	0.3893 (2)	0.0501 (12)
C3	0.9476 (2)	0.1447 (6)	0.3973 (2)	0.0466 (12)
C4	0.7999 (2)	0.3334 (5)	0.4295 (2)	0.0439 (12)
C5	0.7501 (2)	0.3995 (6)	0.4887 (2)	0.0453 (12)
C6	0.7063 (3)	0.5979 (6)	0.4836 (2)	0.0597 (12)
C7	0.6594 (3)	0.6665 (7)	0.5354 (2)	0.0717 (12)
C8	0.6547 (3)	0.5418 (8)	0.5932 (2)	0.0717 (14)
C9	0.6972 (3)	0.3465 (7)	0.5987 (2)	0.0637 (14)
C10	0.7450 (3)	0.2756 (6)	0.5466 (2)	0.0522 (12)
C11	0.7333 (3)	0.3270 (6)	0.3561 (2)	0.0469 (12)
C12	0.6605 (2)	0.1524 (6)	0.3457 (2)	0.0474 (12)
C13	0.5816 (3)	0.1515 (7)	0.3786 (2)	0.0600 (12)
C14	0.5161 (3)	−0.0122 (8)	0.3673 (2)	0.0740 (16)
C15	0.5256 (3)	−0.1749 (8)	0.3217 (2)	0.0735 (16)
C16	0.6031 (3)	−0.1745 (7)	0.2884 (2)	0.0659 (14)
C17	0.6701 (3)	−0.0145 (7)	0.3004 (2)	0.0565 (12)
H6	0.710	0.685	0.444	0.0759*
H7	0.629	0.801	0.531	0.0899*
H8	0.622	0.589	0.629	0.0886*
H9	0.694	0.261	0.639	0.0810*
H10	0.774	0.140	0.551	0.0671*
H13	0.573	0.265	0.409	0.0721*
H14	0.464	−0.011	0.391	0.0899*
H15	0.479	−0.285	0.313	0.0924*
H16	0.611	−0.285	0.257	0.0797*
H17	0.724	−0.019	0.278	0.0696*
H111	0.770	0.312	0.323	0.0506*
H112	0.699	0.464	0.353	0.0481*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0633 (5)	0.0767 (7)	0.0753 (5)	0.0069 (5)	0.0292 (4)	−0.0130 (5)
S2	0.0512 (4)	0.0520 (5)	0.0785 (5)	−0.0040 (4)	0.0236 (4)	−0.0114 (4)
S3	0.0622 (5)	0.0476 (5)	0.0564 (5)	0.0120 (4)	0.0178 (4)	−0.0010 (4)
S4	0.0495 (4)	0.0440 (5)	0.0762 (5)	−0.0020 (4)	0.0211 (4)	−0.0124 (4)
S5	0.0573 (4)	0.0456 (4)	0.0507 (4)	0.0125 (4)	0.0143 (3)	0.0078 (4)
C1	0.049 (2)	0.059 (2)	0.048 (2)	0.006 (2)	0.007 (1)	−0.007 (2)
C2	0.044 (2)	0.048 (2)	0.059 (2)	−0.001 (2)	0.012 (1)	−0.009 (2)
C3	0.049 (2)	0.044 (2)	0.047 (2)	0.006 (2)	0.010 (1)	−0.000 (2)
C4	0.048 (2)	0.039 (2)	0.045 (2)	0.004 (1)	0.010 (1)	0.002 (1)
C5	0.045 (2)	0.047 (2)	0.043 (2)	−0.001 (2)	0.007 (1)	−0.001 (2)
C6	0.073 (2)	0.053 (2)	0.058 (2)	0.010 (2)	0.025 (2)	0.000 (2)
C7	0.084 (2)	0.061 (2)	0.077 (2)	0.014 (2)	0.033 (2)	−0.005 (2)
C8	0.074 (2)	0.083 (3)	0.066 (2)	0.005 (2)	0.033 (2)	−0.012 (2)
C9	0.062 (2)	0.078 (3)	0.055 (2)	0.001 (2)	0.021 (2)	0.007 (2)
C10	0.046 (2)	0.056 (2)	0.055 (2)	0.001 (2)	0.011 (1)	0.003 (2)
C11	0.050 (2)	0.047 (2)	0.044 (2)	0.006 (2)	0.010 (1)	0.004 (1)
C12	0.047 (2)	0.050 (2)	0.042 (2)	0.006 (2)	0.001 (1)	0.002 (2)
C13	0.049 (2)	0.066 (2)	0.064 (2)	−0.002 (2)	0.009 (2)	−0.011 (2)
C14	0.054 (2)	0.088 (3)	0.081 (3)	−0.012 (2)	0.016 (2)	−0.009 (3)
C15	0.067 (2)	0.066 (3)	0.080 (3)	−0.014 (2)	−0.003 (2)	−0.002 (2)
C16	0.078 (3)	0.056 (2)	0.056 (2)	0.004 (2)	−0.005 (2)	−0.006 (2)
C17	0.060 (2)	0.060 (2)	0.047 (2)	0.006 (2)	0.005 (2)	−0.004 (2)

Geometric parameters (Å, º)

S1—C1	1.640 (4)	C8—H8	0.95
S2—C1	1.729 (4)	C9—C10	1.392 (6)
S2—C2	1.733 (4)	C9—H9	0.95
S3—C1	1.736 (4)	C10—H10	0.95
S3—C3	1.731 (4)	C11—C12	1.500 (5)
S4—C2	1.747 (4)	C11—H111	0.91
S4—C4	1.865 (4)	C11—H112	1.00
S5—C3	1.748 (4)	C12—C13	1.390 (6)
S5—C4	1.845 (3)	C12—C17	1.395 (5)
C2—C3	1.336 (5)	C13—C14	1.381 (6)
C4—C5	1.513 (5)	C13—H13	0.95
C4—C11	1.533 (4)	C14—C15	1.378 (7)
C5—C6	1.398 (5)	C14—H14	0.95
C5—C10	1.376 (5)	C15—C16	1.378 (7)
C6—C7	1.373 (6)	C15—H15	0.95
C6—H6	0.95	C16—C17	1.377 (6)
C7—C8	1.376 (6)	C16—H16	0.95
C7—H7	0.95	C17—H17	0.95
C8—C9	1.373 (7)
C1—S2—C2	96.3 (2)	C8—C9—C10	120.4 (4)
C1—S3—C3	96.6 (2)	C8—C9—H9	119.1
C2—S4—C4	92.8 (2)	C10—C9—H9	120.5
C3—S5—C4	92.3 (2)	C5—C10—C9	120.6 (4)
S1—C1—S2	123.0 (2)	C5—C10—H10	119.5
S1—C1—S3	123.5 (3)	C9—C10—H10	119.8
S2—C1—S3	113.4 (2)	C4—C11—C12	115.0 (3)
S2—C2—S4	126.0 (2)	C4—C11—H111	108.3
S2—C2—C3	117.2 (3)	C4—C11—H112	103.8
S4—C2—C3	116.9 (3)	C12—C11—H111	108.1
S3—C3—S5	125.7 (2)	C12—C11—H112	108.8
S3—C3—C2	116.3 (3)	H111—C11—H112	113.0
S5—C3—C2	117.9 (3)	C11—C12—C13	122.5 (3)
S4—C4—S5	105.0 (2)	C11—C12—C17	119.5 (3)
S4—C4—C5	106.9 (2)	C13—C12—C17	117.9 (4)
S4—C4—C11	108.7 (2)	C12—C13—C14	120.6 (4)
S5—C4—C5	112.3 (2)	C12—C13—H13	119.5
S5—C4—C11	109.5 (2)	C14—C13—H13	119.9
C5—C4—C11	113.9 (3)	C13—C14—C15	121.0 (4)
C4—C5—C6	117.7 (3)	C13—C14—H14	118.8
C4—C5—C10	123.9 (3)	C15—C14—H14	120.2
C6—C5—C10	118.4 (3)	C14—C15—C16	118.9 (4)
C5—C6—C7	120.5 (4)	C14—C15—H15	120.7
C5—C6—H6	119.2	C16—C15—H15	120.4
C7—C6—H6	120.3	C15—C16—C17	120.6 (4)
C6—C7—C8	120.7 (4)	C15—C16—H16	120.1
C6—C7—H7	119.5	C17—C16—H16	119.3
C8—C7—H7	119.7	C12—C17—C16	121.0 (4)
C7—C8—C9	119.4 (4)	C12—C17—H17	119.5
C7—C8—H8	120.7	C16—C17—H17	119.5
C9—C8—H8	119.9
C2—S2—C1—S1	179.8 (2)	C5—C6—C7—H7	−179.3
C2—S2—C1—S3	2.9 (2)	H6—C6—C7—C8	−179.4
C1—S2—C2—S4	178.7 (3)	H6—C6—C7—H7	1.3
C1—S2—C2—C3	−0.2 (3)	C6—C7—C8—C9	−0.2 (7)
C3—S3—C1—S1	179.1 (3)	C6—C7—C8—H8	−179.8
C3—S3—C1—S2	−4.0 (2)	H7—C7—C8—C9	179.1
C1—S3—C3—S5	−175.1 (2)	H7—C7—C8—H8	−0.4
C1—S3—C3—C2	4.0 (3)	C7—C8—C9—C10	0.3 (6)
C4—S4—C2—S2	159.6 (3)	C7—C8—C9—H9	179.6
C4—S4—C2—C3	−21.6 (3)	H8—C8—C9—C10	179.9
C2—S4—C4—S5	35.0 (2)	H8—C8—C9—H9	−0.9
C2—S4—C4—C5	154.5 (2)	C8—C9—C10—C5	−0.2 (6)
C2—S4—C4—C11	−82.1 (3)	C8—C9—C10—H10	−179.8
C4—S5—C3—S3	−155.6 (2)	H9—C9—C10—C5	−179.5
C4—S5—C3—C2	25.3 (3)	H9—C9—C10—H10	0.9
C3—S5—C4—S4	−35.8 (2)	C4—C11—C12—C13	71.5 (5)
C3—S5—C4—C5	−151.6 (3)	C4—C11—C12—C17	−109.8 (4)
C3—S5—C4—C11	80.8 (3)	H111—C11—C12—C13	−167.4
S2—C2—C3—S3	−2.7 (4)	H111—C11—C12—C17	11.3
S2—C2—C3—S5	176.6 (2)	H112—C11—C12—C13	−44.4
S4—C2—C3—S3	178.4 (2)	H112—C11—C12—C17	134.3
S4—C2—C3—S5	−2.4 (4)	C11—C12—C13—C14	179.8 (4)
S4—C4—C5—C6	60.8 (4)	C11—C12—C13—H13	0.3
S4—C4—C5—C10	−119.7 (3)	C17—C12—C13—C14	1.1 (6)
S5—C4—C5—C6	175.4 (3)	C17—C12—C13—H13	−178.3
S5—C4—C5—C10	−5.1 (4)	C11—C12—C17—C16	−178.4 (4)
C11—C4—C5—C6	−59.4 (4)	C11—C12—C17—H17	2.7
C11—C4—C5—C10	120.1 (4)	C13—C12—C17—C16	0.4 (6)
S4—C4—C11—C12	170.5 (3)	C13—C12—C17—H17	−178.6
S4—C4—C11—H111	49.5	C12—C13—C14—C15	−2.0 (7)
S4—C4—C11—H112	−70.8	C12—C13—C14—H14	178.3
S5—C4—C11—C12	56.3 (3)	H13—C13—C14—C15	177.5
S5—C4—C11—H111	−64.7	H13—C13—C14—H14	−2.3
S5—C4—C11—H112	175.0	C13—C14—C15—C16	1.3 (7)
C5—C4—C11—C12	−70.3 (4)	C13—C14—C15—H15	−177.9
C5—C4—C11—H111	168.6	H14—C14—C15—C16	−178.9
C5—C4—C11—H112	48.4	H14—C14—C15—H15	1.9
C4—C5—C6—C7	179.6 (4)	C14—C15—C16—C17	0.1 (6)
C4—C5—C6—H6	−1.0	C14—C15—C16—H16	−180.0
C10—C5—C6—C7	0.0 (5)	H15—C15—C16—C17	179.3
C10—C5—C6—H6	179.5	H15—C15—C16—H16	−0.8
C4—C5—C10—C9	−179.5 (3)	C15—C16—C17—C12	−1.0 (6)
C4—C5—C10—H10	0.1	C15—C16—C17—H17	178.0
C6—C5—C10—C9	0.0 (6)	H16—C16—C17—C12	179.1
C6—C5—C10—H10	179.7	H16—C16—C17—H17	−2.0
C5—C6—C7—C8	0.1 (6)