2-Sulfanylidene-1,3-dithiolo[4,5-b]naphtho­[2,3-e][1,4]dithiine-5,10-dione

Miguel Angel Méndez-Rojas; Sylvain Bernès; Aarón Pérez-Benítez; María Fernanda Romero Zarazúa; Adrián Castellanos-Uribe

doi:10.1107/S1600536811039079

. 2011 Oct 5;67(Pt 11):o2837. doi: 10.1107/S1600536811039079

2-Sulfanylidene-1,3-dithiolo[4,5-b]naphtho[2,3-e][1,4]dithiine-5,10-dione

Miguel Angel Méndez-Rojas ^a, Sylvain Bernès ^b,^*, Aarón Pérez-Benítez ^c, María Fernanda Romero Zarazúa ^a, Adrián Castellanos-Uribe ^a

PMCID: PMC3247576 PMID: 22219881

Abstract

The title molecule, C₁₃H₄O₂S₅, is folded by 47.83 (6)° along the S⋯S vector of the [1,4]dithiine six-membered ring, with the naphthoquinone and [1,3]dithiole-2-thione moieties being nearly planar [largest deviations from least-squares planes = 0.028 (2) and 0.016 (1) Å, respectively]. This boat conformation is close to that observed in the analogous compound [Mendez-Rojas et al. (2001). J. Chem. Crystallogr. 31, 17–28] including a 2-oxo group [folding angle: 42.3 (1)° at 213 (2) K]. Both compounds are indeed isomorphous, and the small difference in the folding angle probably results from the involvement of the thioxo group of the title compound in intermolecular S⋯S contacts [3.5761 (13) Å]. In the crystal structure, molecules are stacked in the [100] direction, with dithiole rings making π–π interactions. In a stack, alternating short and long separations are observed between the centroids of dithiole rings, 3.5254 (17) and 4.7010 (18) Å.

Related literature

For general background to sulfur-containing heterocycles in organic conductors, see: Wudl (1984 ▶); Jérome (2007 ▶). For dithiine derivatives and their redox behavior, see: Hayakawa et al. (1982 ▶); Kao et al. (1985 ▶); Kniess & Mayer (1996 ▶); Brisse et al. (2000 ▶); Mendez-Rojas et al. (2001 ▶). For the synthesis of the precursor of the title dithiine, see: Wang et al. (1998 ▶).

Experimental

Crystal data

C₁₃H₄O₂S₅
M _r = 352.46
Triclinic,
a = 7.8527 (8) Å
b = 8.0281 (9) Å
c = 12.0022 (13) Å
α = 97.934 (9)°
β = 89.227 (9)°
γ = 117.867 (8)°
V = 661.37 (12) Å³
Z = 2
Mo Kα radiation
μ = 0.87 mm⁻¹
T = 296 K
0.48 × 0.12 × 0.08 mm

Data collection

Siemens P4 diffractometer
Absorption correction: ψ scan (XSCANS; Siemens, 1996 ▶) T _min = 0.679, T _max = 0.733
3881 measured reflections
2323 independent reflections
1748 reflections with I > 2σ(I)
R _int = 0.026
2 standard reflections every 48 reflections intensity decay: 2%

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.090
S = 1.02
2323 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: XSCANS (Siemens, 1996 ▶); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811039079/yk2021sup1.cif

e-67-o2837-sup1.cif^{(20.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811039079/yk2021Isup2.hkl

e-67-o2837-Isup2.hkl^{(114.1KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811039079/yk2021Isup3.mol

Supplementary material file. DOI: 10.1107/S1600536811039079/yk2021Isup4.cml

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

Acknowledgments

Financial support from CONACyT-48038-R and VIPE-UDLA are gratefully acknowledged.

supplementary crystallographic information

Comment

The development of new types of π-electron donors and acceptors with high polarizability continues to be an attractive topic in material sciences. Such compounds are not only interesting as candidates for single-component conductors, but also because they have low excitation energies and promising applications as NLO materials and near-IR absorbing dyes. Sulfur-based heterocycles are good candidates for building such materials, and donors like TTF and BEDT-TTF became emblematic systems in the 70's, after they allowed to synthesize molecular metals and superconductor materials (Wudl, 1984; Jérome, 2007).

The title compound belongs to the 1,4-dithiine derivatives, which have a particular conformational flexibility, because the energy barrier between the planar and boat conformations is very low (Hayakawa et al., 1982). Ab initio computations showed for example that for 1,4-dithiine, the C₂_v(boat) →D₂_h(planar) conformational interconversion requires less than 3 kcal/mol (see Table II and Fig. 4 in Kao et al., 1985). A fine tuning of the geometry and electron distribution may thus be expected by varying the substituents of this heterocycle. For example, electron withdrawing groups seem to stabilize the unfolded conformer (Brisse et al., 2000).

In contrast, the title molecule (Kniess & Mayer, 1996; Mendez-Rojas et al., 2001) adopts a folded conformation (Fig. 1). The dihedral angle between the essentially planar naphthoquinone ring (C4a/C5/C5a/C6···C9/C9a/C10/C10a; max. deviation: 0.028 Å for C4a) and the five membered 1,3-dithiole ring (S1/C2/S3/C3a/C11a; max. deviation: 0.016 Å for C2) is 47.83 (6)°. This boat conformation is favored by intramolecular S···O repulsion effects, characterized by non-bonding distances S11···O10 = 2.874 (2) and S4···O5 = 2.868 (2) Å. Heteroatoms are also involved in intermolecular contacts. Molecules form centrosymmetric dimers through S1···S2ⁱ contacts [3.5761 (13) Å; symmetry code (i): 1 - x, 3 - y, 1 - z] between the thioxo group and one S atom of the dithiole heterocycle. The contacts pattern is completed by bifurcated S1/S11···O5ⁱⁱ interactions [3.158 (2) and 3.159 (2) Å; symmetry code (ii): 1 + x, 1 + y, z], forming a two-dimensional network of contacts in the crystal (Fig. 2). This arrangement is compatible with a stacking structure for molecules, in the [100] direction: two dithiole rings related by inversion give a π···π interaction characterized by a centroid to centroid separation of 3.5254 (17) Å. However, as a consequence of the triclinic symmetry, the following stacked ring generated by inversion is found at a different distance, 4.7010 (18) Å. Short and long separations thus alternate along the stack (Fig. 2, inset), a common situation for one-dimensional materials affected by a Peierls distortion.

The title molecule is isomorphous with the 2-oxo analogue (Mendez-Rojas et al., 2001). However, it is interesting to note that both the molecular and the crystal structures present significantly different metrics for the 2-thioxo and the 2-oxo compounds. In the latter, the folding angle is 42.3 (1)°, and the separations in the dithiole stacks parallel to [100] are 3.566 and 4.345 Å. Despite of the clear dimerization along the stacks for both compounds, the title molecule seems to be more prone to Peierls instability, compared to its 2-oxo analogue.

Experimental

The precursor (NBu₄)₂[Zn(dmit)₂], where H₂dmit is 4,5-dimercapto-1,3-dithiole-2-thione, was prepared as previously reported (Wang et al., 1998). This complex (1.68 g, 2.20 mmol in 20 ml acetone) was reacted with 2,3-dichloro-1,4-naphthoquinone (1 g, 4.40 mmol) at room temperature, forming immediately a dark precipitate. The mixture was stirred overnight and the precipitate was then recovered by vacuum filtration (1.50 g, 99%) and recrystallized from CH₂Cl₂. Small black shiny needles suitable for X-ray diffraction were obtained after several days. M.p. 354–355 °C. IR (KBr, cm^-1) 1663 (vs), 1586 (m), 1553 (m), 1493 (m), 1385 (sm), 1275 (vs), 1134 (m), 1073 (vs), 794 (m), 706 (s), 635 (sm), 505 (sm); ¹H-NMR (CDCl₃, p.p.m.) δ, 7.80 (dd, 2H), 8.16 (dd, 2H). Anal. calcd. for C₁₃H₄O₂S₅: C 44.3%; found: C 42.9%.