Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101006679/fr1325sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270101006679/fr1325VIIsup2.hkl |
CCDC reference: 170180
2[5-(oxo-1,2-diphenylethylsulfanyl)-2-thioxo-1,3-dithiol-4-ylsulfanyl]- 1,2-diphenyl-1-ethanone, (V). To a solution of dithiolate, (III) (0.26 g, 1 mmol) in dry ethanol (10 ml) and under nitrogen atmosphere was added desyl chloride, (IV) (0.5 g, 2 mmol) dropwise, the solution was then stirred at room temperature for 3 h. The yellow precipitate was filtered and washed with ethanol (5 ml),and 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, (VI). A solution of 1,8-diketone (5) (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 3 h. Then, the solvent was evaporated under reduced pressure and the remainder viscous material was chromatographed eluting with hexane-dichloromethane (3:1). m.p. 401–402 K (0.17 g, 25%). 1H NMR (200 MHz, CDCl3) δ 7.40–7.18 (8H, m, Ph) 6.92 (2H, d, J = 12 Hz, Ph) 3.76 (2H, s, PhCH2), 13C NMR (50.32 Hz, CDCl3) δ 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.
5,6-Diphenyl[1,3]dithiolo[4,5-b][1,4]dithiine-2-thione, (VII). Same reaction as for (VI) was repeated in dark. The crude material was purified by column chromatography (3:1, hexane/CH2Cl2), which gave 65% of (VII). m.p. 386–387 K. 1H NMR (250 MHz, CDCl3) L 7.09–7.34 (m, 10 H). 13C NMR (67.8 MHz, CDCl3) L 213.9 (C═S), 136.2 (C-q), 134.7 (C-q), 129.9 (C-q), 129.5 (C-t), 128.7 (C-t), 128.6 (C-t); HRMS m/z calculated 373.9386; measured 373.9397 for C17H10S5. Calculated C 54.5, H 2.69; found C 54.44, H 2.66. IR ν 1080 cm-1 (C═S). UV λmax (CH3CN) 391 nm.
The structure was determined by direct method and refined by least square full matrix method. All non-H atoms were refined with anisotropic displacement parameters. The H atoms were placed geometrically 0.93 Å from their parent atoms and displacement parameters were refined isotropically.
Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1993); data reduction: MolEN (Fair, 1990); program(s) used to solve structure: Sir-MolEN (Burla et al., 1989); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Johnson & Burnett, 2000); software used to prepare material for publication: PLATON (Spek, 1990).
Fig. 1. ORTEPIII (Johnson & Burnett, 2000) drawing of the asymmetric unit of the title compound with the atomic numbering scheme. The displacement ellipsoids are drawn at the 50% probability level. |
C17H10S5 | Dx = 1.499 Mg m−3 |
Mr = 374.55 | Cu Kα radiation, λ = 1.5418 Å |
Monoclinic, P21/n | Cell parameters from 19 reflections |
a = 12.343 (2) Å | θ = 15.5–42.6° |
b = 5.273 (1) Å | µ = 6.36 mm−1 |
c = 26.029 (7) Å | T = 295 K |
β = 101.54 (2)° | Prismatic, light brown |
V = 1659.8 (6) Å3 | 0.48 × 0.20 × 0.12 mm |
Z = 4 |
Enraf-Nonius CAD-4 diffractometer | Rint = 0.075 |
ω/2θ scans | θmax = 74.2° |
Absorption correction: empirical (using intensity measurements) via ψ scans (fair, 1990) ? | h = 0→15 |
Tmin = 0.272, Tmax = 0.466 | k = 0→6 |
3865 measured reflections | l = −32→31 |
3393 independent reflections | 3 standard reflections every 120 min |
2125 reflections with I > 2σ(I) | intensity decay: 1% |
Refinement on F | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.058 | w = 1/[σ2(Fo2) + (0.0945P)2 + 0.0036P], where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.149 | (Δ/σ)max < 0.001 |
S = 1.06 | Δρmax = 0.44 e Å−3 |
2125 reflections | Δρmin = −0.44 e Å−3 |
209 parameters |
C17H10S5 | V = 1659.8 (6) Å3 |
Mr = 374.55 | Z = 4 |
Monoclinic, P21/n | Cu Kα radiation |
a = 12.343 (2) Å | µ = 6.36 mm−1 |
b = 5.273 (1) Å | T = 295 K |
c = 26.029 (7) Å | 0.48 × 0.20 × 0.12 mm |
β = 101.54 (2)° |
Enraf-Nonius CAD-4 diffractometer | 2125 reflections with I > 2σ(I) |
Absorption correction: empirical (using intensity measurements) via ψ scans (fair, 1990) ? | Rint = 0.075 |
Tmin = 0.272, Tmax = 0.466 | 3 standard reflections every 120 min |
3865 measured reflections | intensity decay: 1% |
3393 independent reflections |
R[F2 > 2σ(F2)] = 0.058 | 209 parameters |
wR(F2) = 0.149 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.44 e Å−3 |
2125 reflections | Δρmin = −0.44 e Å−3 |
x | y | z | Uiso*/Ueq | ||
S1 | 0.43280 (11) | −0.4350 (3) | 0.05940 (5) | 0.0802 (5) | |
S2 | 0.61201 (8) | −0.0864 (3) | 0.04250 (4) | 0.0600 (4) | |
S3 | 0.58966 (9) | −0.2000 (3) | 0.14854 (4) | 0.0630 (4) | |
S4 | 0.79573 (9) | 0.2950 (3) | 0.07882 (5) | 0.0636 (4) | |
S5 | 0.77336 (9) | 0.1645 (3) | 0.19547 (4) | 0.0647 (4) | |
C1 | 0.5382 (3) | −0.2495 (10) | 0.08195 (17) | 0.0584 (12) | |
C2 | 0.6966 (3) | 0.0834 (10) | 0.09214 (16) | 0.0538 (11) | |
C3 | 0.6857 (3) | 0.0294 (10) | 0.14119 (17) | 0.0553 (11) | |
C4 | 0.9024 (3) | 0.1401 (9) | 0.17555 (15) | 0.0487 (10) | |
C5 | 0.9136 (3) | 0.1884 (9) | 0.12645 (15) | 0.0486 (10) | |
C6 | 1.0150 (3) | 0.1574 (9) | 0.10448 (14) | 0.0475 (10) | |
C7 | 1.0860 (4) | −0.0418 (10) | 0.11800 (17) | 0.0611 (12) | |
C8 | 1.1812 (4) | −0.0653 (12) | 0.0973 (2) | 0.0706 (14) | |
C9 | 1.2037 (4) | 0.1098 (13) | 0.0621 (2) | 0.0749 (16) | |
C10 | 1.1350 (4) | 0.3135 (13) | 0.0487 (2) | 0.0767 (16) | |
C11 | 1.0415 (4) | 0.3368 (11) | 0.06967 (18) | 0.0637 (13) | |
C12 | 0.9951 (3) | 0.0756 (9) | 0.22075 (15) | 0.0467 (9) | |
C13 | 1.0860 (4) | 0.2310 (9) | 0.23258 (17) | 0.0530 (11) | |
C14 | 1.1696 (4) | 0.1774 (10) | 0.27600 (17) | 0.0606 (12) | |
C15 | 1.1602 (4) | −0.0326 (10) | 0.30618 (16) | 0.0592 (12) | |
C16 | 1.0703 (4) | −0.1879 (10) | 0.29423 (18) | 0.0639 (12) | |
C17 | 0.9858 (4) | −0.1352 (9) | 0.25161 (16) | 0.0542 (11) | |
H7 | 1.0705 | −0.1634 | 0.1414 | 0.079 (17)* | |
H8 | 1.2294 | −0.1999 | 0.1073 | 0.11 (2)* | |
H9 | 1.2657 | 0.0906 | 0.0473 | 0.12 (2)* | |
H10 | 1.1514 | 0.4354 | 0.0256 | 0.072 (15)* | |
H11 | 0.9950 | 0.4752 | 0.0604 | 0.11 (2)* | |
H13 | 1.0920 | 0.3716 | 0.2117 | 0.072 (16)* | |
H14 | 1.2310 | 0.2828 | 0.2844 | 0.068 (14)* | |
H15 | 1.2158 | −0.0690 | 0.3350 | 0.053 (12)* | |
H16 | 1.0654 | −0.3301 | 0.3148 | 0.081 (17)* | |
H17 | 0.9240 | −0.2397 | 0.2438 | 0.051 (12)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0606 (7) | 0.1022 (12) | 0.0803 (9) | −0.0208 (8) | 0.0202 (6) | −0.0261 (8) |
S2 | 0.0391 (5) | 0.0896 (10) | 0.0490 (6) | 0.0020 (6) | 0.0033 (4) | −0.0049 (5) |
S3 | 0.0479 (6) | 0.0892 (10) | 0.0542 (6) | −0.0004 (6) | 0.0158 (4) | −0.0060 (6) |
S4 | 0.0443 (5) | 0.0792 (9) | 0.0621 (7) | 0.0223 (6) | −0.0020 (4) | −0.0021 (6) |
S5 | 0.0460 (5) | 0.0985 (11) | 0.0500 (6) | −0.0153 (6) | 0.0106 (4) | −0.0007 (6) |
C1 | 0.043 (2) | 0.076 (3) | 0.058 (2) | −0.007 (2) | 0.0138 (18) | 0.000 (2) |
C2 | 0.0338 (18) | 0.075 (3) | 0.050 (2) | 0.003 (2) | 0.0032 (15) | −0.001 (2) |
C3 | 0.0389 (19) | 0.071 (3) | 0.056 (2) | −0.003 (2) | 0.0108 (16) | 0.001 (2) |
C4 | 0.042 (2) | 0.057 (3) | 0.047 (2) | −0.0043 (19) | 0.0076 (15) | −0.0032 (19) |
C5 | 0.0424 (19) | 0.055 (3) | 0.047 (2) | −0.004 (2) | 0.0072 (16) | −0.0078 (19) |
C6 | 0.044 (2) | 0.057 (3) | 0.0383 (19) | −0.0001 (18) | −0.0001 (15) | −0.0078 (19) |
C7 | 0.070 (3) | 0.068 (3) | 0.051 (2) | 0.007 (2) | 0.025 (2) | 0.007 (3) |
C8 | 0.068 (3) | 0.083 (4) | 0.064 (3) | 0.005 (3) | 0.021 (2) | 0.017 (3) |
C9 | 0.057 (3) | 0.111 (5) | 0.061 (3) | 0.002 (3) | 0.022 (2) | −0.008 (3) |
C10 | 0.063 (3) | 0.107 (5) | 0.062 (3) | 0.019 (3) | 0.017 (2) | −0.020 (3) |
C11 | 0.052 (2) | 0.078 (4) | 0.058 (3) | 0.022 (2) | 0.0042 (19) | −0.004 (3) |
C12 | 0.046 (2) | 0.055 (3) | 0.0406 (19) | −0.0065 (18) | 0.0103 (15) | 0.0012 (19) |
C13 | 0.054 (2) | 0.053 (3) | 0.049 (2) | −0.003 (2) | 0.0013 (17) | −0.007 (2) |
C14 | 0.054 (2) | 0.067 (3) | 0.055 (2) | −0.004 (2) | −0.0027 (19) | −0.015 (2) |
C15 | 0.061 (3) | 0.070 (3) | 0.041 (2) | 0.000 (2) | −0.0067 (18) | 0.005 (2) |
C16 | 0.078 (3) | 0.062 (3) | 0.052 (2) | 0.007 (2) | 0.015 (2) | 0.000 (3) |
C17 | 0.054 (2) | 0.057 (3) | 0.052 (2) | 0.000 (2) | 0.0122 (18) | −0.010 (2) |
C1—S1 | 1.639 (5) | C8—H8 | 0.9300 |
C1—S2 | 1.732 (5) | C9—C10 | 1.369 (8) |
C1—S3 | 1.742 (5) | C9—H9 | 0.9300 |
C2—C3 | 1.341 (6) | C10—C11 | 1.378 (7) |
C2—S2 | 1.739 (4) | C10—H10 | 0.9300 |
C2—S4 | 1.741 (5) | C11—H11 | 0.9300 |
C3—S3 | 1.731 (5) | C12—C13 | 1.375 (6) |
C3—S5 | 1.750 (5) | C12—C17 | 1.389 (6) |
C4—C5 | 1.337 (6) | C13—C14 | 1.398 (6) |
C4—C12 | 1.507 (5) | C13—H13 | 0.9300 |
C4—S5 | 1.776 (4) | C14—C15 | 1.376 (7) |
C5—C6 | 1.485 (6) | C14—H14 | 0.9300 |
C5—S4 | 1.802 (4) | C15—C16 | 1.365 (7) |
C6—C7 | 1.369 (6) | C15—H15 | 0.9300 |
C6—C11 | 1.393 (6) | C16—C17 | 1.390 (6) |
C7—C8 | 1.393 (6) | C16—H16 | 0.9300 |
C7—H7 | 0.9300 | C17—H17 | 0.9300 |
C8—C9 | 1.367 (8) | ||
S1—C1—S2 | 123.9 (3) | C9—C10—H10 | 120.2 |
S1—C1—S3 | 123.4 (3) | C11—C10—H10 | 120.2 |
S2—C1—S3 | 112.6 (3) | C10—C11—C6 | 121.5 (5) |
C3—C2—S2 | 116.0 (4) | C10—C11—H11 | 119.3 |
C3—C2—S4 | 122.3 (3) | C6—C11—H11 | 119.3 |
S2—C2—S4 | 121.6 (2) | C13—C12—C17 | 120.4 (4) |
C2—C3—S3 | 117.1 (3) | C13—C12—C4 | 119.9 (4) |
C2—C3—S5 | 121.2 (4) | C17—C12—C4 | 119.7 (4) |
S3—C3—S5 | 121.4 (3) | C12—C13—C14 | 119.9 (4) |
C5—C4—C12 | 125.6 (4) | C12—C13—H13 | 120.1 |
C5—C4—S5 | 122.4 (3) | C14—C13—H13 | 120.1 |
C12—C4—S5 | 111.9 (3) | C15—C14—C13 | 119.5 (4) |
C4—C5—C6 | 127.1 (4) | C15—C14—H14 | 120.3 |
C4—C5—S4 | 119.5 (3) | C13—C14—H14 | 120.3 |
C6—C5—S4 | 113.3 (3) | C16—C15—C14 | 120.7 (4) |
C7—C6—C11 | 117.8 (4) | C16—C15—H15 | 119.7 |
C7—C6—C5 | 122.1 (4) | C14—C15—H15 | 119.7 |
C11—C6—C5 | 120.1 (4) | C15—C16—C17 | 120.5 (5) |
C6—C7—C8 | 121.0 (5) | C15—C16—H16 | 119.7 |
C6—C7—H7 | 119.5 | C17—C16—H16 | 119.7 |
C8—C7—H7 | 119.5 | C16—C17—C12 | 119.1 (4) |
C9—C8—C7 | 120.0 (5) | C16—C17—H17 | 120.5 |
C9—C8—H8 | 120.0 | C12—C17—H17 | 120.5 |
C7—C8—H8 | 120.0 | C1—S2—C2 | 97.1 (2) |
C8—C9—C10 | 120.2 (5) | C3—S3—C1 | 96.7 (2) |
C8—C9—H9 | 119.9 | C2—S4—C5 | 99.6 (2) |
C10—C9—H9 | 119.9 | C3—S5—C4 | 100.39 (19) |
C9—C10—C11 | 119.6 (5) | ||
S2—C2—C3—S3 | −0.1 (5) | C17—C12—C13—C14 | −0.2 (7) |
S4—C2—C3—S3 | −175.9 (3) | C4—C12—C13—C14 | 177.0 (4) |
S2—C2—C3—S5 | 174.4 (3) | C12—C13—C14—C15 | 0.6 (7) |
S4—C2—C3—S5 | −1.4 (6) | C13—C14—C15—C16 | −0.2 (8) |
C12—C4—C5—C6 | 8.4 (8) | C14—C15—C16—C17 | −0.7 (7) |
S5—C4—C5—C6 | −175.4 (4) | C15—C16—C17—C12 | 1.1 (7) |
C12—C4—C5—S4 | −173.5 (4) | C13—C12—C17—C16 | −0.6 (6) |
S5—C4—C5—S4 | 2.6 (6) | C4—C12—C17—C16 | −177.9 (4) |
C4—C5—C6—C7 | 38.5 (7) | S1—C1—S2—C2 | 174.6 (3) |
S4—C5—C6—C7 | −139.7 (4) | S3—C1—S2—C2 | −6.6 (3) |
C4—C5—C6—C11 | −140.3 (5) | C3—C2—S2—C1 | 4.1 (4) |
S4—C5—C6—C11 | 41.5 (5) | S4—C2—S2—C1 | 180.0 (3) |
C11—C6—C7—C8 | −0.5 (7) | C2—C3—S3—C1 | −4.0 (4) |
C5—C6—C7—C8 | −179.3 (4) | S5—C3—S3—C1 | −178.5 (3) |
C6—C7—C8—C9 | −1.2 (8) | S1—C1—S3—C3 | −174.6 (3) |
C7—C8—C9—C10 | 2.5 (8) | S2—C1—S3—C3 | 6.5 (3) |
C8—C9—C10—C11 | −1.9 (8) | C3—C2—S4—C5 | 45.0 (4) |
C9—C10—C11—C6 | 0.1 (8) | S2—C2—S4—C5 | −130.5 (3) |
C7—C6—C11—C10 | 1.0 (7) | C4—C5—S4—C2 | −45.1 (4) |
C5—C6—C11—C10 | 179.9 (4) | C6—C5—S4—C2 | 133.2 (3) |
C5—C4—C12—C13 | 52.8 (6) | C2—C3—S5—C4 | −42.2 (5) |
S5—C4—C12—C13 | −123.6 (4) | S3—C3—S5—C4 | 132.0 (3) |
C5—C4—C12—C17 | −129.9 (5) | C5—C4—S5—C3 | 41.2 (4) |
S5—C4—C12—C17 | 53.6 (5) | C12—C4—S5—C3 | −142.2 (3) |
Experimental details
Crystal data | |
Chemical formula | C17H10S5 |
Mr | 374.55 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 295 |
a, b, c (Å) | 12.343 (2), 5.273 (1), 26.029 (7) |
β (°) | 101.54 (2) |
V (Å3) | 1659.8 (6) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 6.36 |
Crystal size (mm) | 0.48 × 0.20 × 0.12 |
Data collection | |
Diffractometer | Enraf-Nonius CAD-4 diffractometer |
Absorption correction | Empirical (using intensity measurements) via ψ scans (Fair, 1990) |
Tmin, Tmax | 0.272, 0.466 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3865, 3393, 2125 |
Rint | 0.075 |
(sin θ/λ)max (Å−1) | 0.624 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.058, 0.149, 1.06 |
No. of reflections | 2125 |
No. of parameters | 209 |
No. of restraints | ? |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.44, −0.44 |
Computer programs: CAD-4 EXPRESS (Enraf-Nonius, 1993), MolEN (Fair, 1990), Sir-MolEN (Burla et al., 1989), SHELXL97 (Sheldrick, 1997), ORTEPIII (Johnson & Burnett, 2000), PLATON (Spek, 1990).
C1—S1 | 1.639 (5) | C3—S3 | 1.731 (5) |
C1—S2 | 1.732 (5) | C3—S5 | 1.750 (5) |
C1—S3 | 1.742 (5) | C4—C5 | 1.337 (6) |
C2—C3 | 1.341 (6) | C4—S5 | 1.776 (4) |
C2—S2 | 1.739 (4) | C5—S4 | 1.802 (4) |
C2—S4 | 1.741 (5) | ||
S1—C1—S2 | 123.9 (3) | C5—C4—S5 | 122.4 (3) |
S2—C1—S3 | 112.6 (3) | C4—C5—C6 | 127.1 (4) |
C3—C2—S2 | 116.0 (4) | C6—C7—C8 | 121.0 (5) |
C3—C2—S4 | 122.3 (3) | C1—S2—C2 | 97.1 (2) |
C2—C3—S3 | 117.1 (3) | C3—S3—C1 | 96.7 (2) |
C2—C3—S5 | 121.2 (4) | C2—S4—C5 | 99.6 (2) |
C5—C4—C12 | 125.6 (4) | C3—S5—C4 | 100.39 (19) |
There has been wide interest in the introduction of the increased conjugation to bis(ethylenedithio)tetrathiafulvalene, BEDT-TTF (or ET), (I), which is an electron-donating molecule. Its radical cation salts show electrical conductivity and, in some cases, superconductivity at lower temperatures (Williams et al., 1985). Although the extension has been well achieved in the middle of the molecule (Bryce, 1995), there are limited examples of introduction of conjugation at the peripheral ethylene groups (Inoue et al., 1986; Yamada et al., 1996; Skabara et al., 1999). This is mainly due to the availability of the limited methodology in the literature.
In this context, attempts to synthesize a fully unsaturated ET analogue with phenyl groups at the peripherals (II) have failed so far (Noh at al., 1996; Lee et al., 1998; Lee & Noh, 1998). On the other hand, we recently reported a concise synthesis of 5,6-diphenyl[1,3] dithiolo[4,5-d]dithiine-2-thione (VII) and its coupling product, a fully unsaturated and tetra-phenyl substituted ET analogue, (II) (Ertaş & Öztürk, 2000), by employing 1,8-diketone ring formation using P4S10 in dark (Öztürk, 1996) which proved that 1,8-diketone ring formation reaction is an efficient procedure for the synthesis of fused and substituted 1,4-dithiin rings.
The diketone (V) was prepared from the reaction of the readily available dithiolate (III) (Svenstrup & Becher, 1995) with desyl chloride in ethanol under nitrogen atmosphere. Surprisingly, when the diketone (V) was refluxed in toluene, benzylphenyldithiole ring (VI) was obtained rather than the desired dithiin ring (VII). The crystal structure of (VI) was determined and will be published (Kaynak et al., 2001). In the light of this result, it was suggested that the reaction proceeds via a radical mechanism, which led us to repeat the reaction this time in dark. Thus, the diphenyldithiin (VII) was obtained in 65% yield. \sch
We report here the crystal structure of 5,6-diphenyl[1,3]dithiolo[4,5-d]dithiine-2-thione, (VII). The structure predicted from chemical and spectral analysis is confirmed. The molecular structure is shown in Fig. 1. Structural results show that the six-membered ring adopts the boat conformation having the spherical polar set values (Cremer & Pople, 1975) Q = 0.770 (3) Å, θ = 91.6 (3)° and ϕ = 178.9.0 (3)°. Atoms S4 and S5 are displaced from the C2/C3/C4/C5 mean plane by -0.697 (2) and -0.636 (2) Å, respectively. The dithiole ring fused to the six-membered ring also deviates from planarity while atom C1 is placed fom the S2/C2/C3/S3 mean plane by 0.122 (5) Å. The puckering parameters of this ring Q = 0.077 (4) Å and ϕ = 36 (3)°; so the dithiole ring assumes an envelope conformation. The dihedral angle between the S2/C2/C3/S3 and C2/C3/C4/C5 mean planes of 31.5 (2)°. No structure determinations of molecules containing this heterocyclic system have been reported. However, it has also been stated that trace amount of the title compound was occasionaly separated as needle-shaped crystal and identified by crystal structure analysis (Lee & Noh, 1998).
The bonds in the dithiole ring are very similar to those for 5-benzyl-5-phenyl[1,3]dithiolo[4,5-d][1,3]dithiole-2-thione (Kaynak et al., 2001). The six-membered ring of the fused heterocycle (dithiine, hereafter) is affected by the presence of the phenyl substituents. The increase in the electron density of dithiine ring due to the phenyl groups has made the S5—C4 and S4—C5 bond distances in (VII) [1.776 (4) and 1.802 (4) Å, respectively] longer than the values of S5—C3 and S4—C2 [1.750 (5) and 1.741 (5) Å, respectively]. In the molecule, the double bond distances are: S1═C1 1.639 (5), C2═C3 1.341 (6) and C4═C5 1.337 (6) Å. Similar bond lengths have been reported for the crystal structures of 4,5-(1',2'-diphenylethylenedithio)-1,3-dithiole-2-thione (Lee & Noh, 1998) and 5-benzyl-5-phenyl-[1,3]dithiolo[4,5-d][1,3]dithiole-2-thione (Kaynak et al., 2001). The phenyl rings are essentially planar [maximum deviations being -0.013 (6) and 0.006 (5) Å for C9 and C16, respectively] and twisted out of the C2/C3/C4/C5 mean plane of the dithiine ring with torsion angles of 53.6 (5) and -139.7 (4)° for S5—C4—C12—C17 and S4—C5—C6—C7, respectively; the dihedral angle between phenyl groups is 59.1 (2)°.
In the title molecule, the shortest intermolecular contact is S2···S2(1 - x, -y, -z) 3.305 (2) Å which is shorter than the sum of the van der Waals radii. Of particular note is the short non-bonding intramolecular distances observed for H11···S4 and H7···C12, at 2.77 and 2.74 Å, respectively.