Dimethyl 2,2′-[butane-1,4-diylbis(sul­fanediyl)]dibenzoate

Iván Brito; Alejandro Cárdenas; Joselyn Albanez; Michael Bolte; Matías López-Rodríguez

doi:10.1107/S1600536809042846

. 2009 Oct 23;65(Pt 11):o2828–o2829. doi: 10.1107/S1600536809042846

Dimethyl 2,2′-[butane-1,4-diylbis(sulfanediyl)]dibenzoate

Iván Brito ^a,^*, Alejandro Cárdenas ^b, Joselyn Albanez ^a, Michael Bolte ^c, Matías López-Rodríguez ^d

PMCID: PMC2971371 PMID: 21578419

Abstract

The title compound, C₂₀H₂₂O₄S₂, was synthesized by the reaction of 1,4-dibromobutene with methyl thiosalicylate. The aliphatic segment of this ligand is in an all-trans conformation. The bridging chain, –S-(CH₂)₄-S–, is almost planar (r.m.s. deviation for all non-H atoms: 0.056 Å) and its mean plane forms dihedral angles of 16.60 (7) and 5.80 (2)° with the aromatic rings. In the crystal, the molecules are linked by weak C—H⋯O interactions into chains with graph-set notation C(14) along [0 0 1]. The crystal studied was a racemic twin, the ratio of the twin components being 0.27 (9):0.73 (9).

Related literature

For the potential of coordination polymers based on multitopic bridging ligands and metal centers as functional materials, see: Guo et al. (2002 ▶); Melcer et al. (2001 ▶). For the use of flexible ligands in such structures, see: Bu et al. (2001 ▶); Withersby et al. (1997 ▶). For our studies on the synthesis and structural characterization of divalent sulfur compounds, see: Brito et al. (2004 ▶, 2005 ▶, 2006 ▶). For a related compound, see: Awaleh et al. (2005 ▶). For graph-set notation of hydrogen bonds, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₀H₂₂O₄S₂
M _r = 390.5
Orthorhombic,
a = 7.4027 (7) Å
b = 14.2976 (11) Å
c = 17.7396 (13) Å
V = 1877.6 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.31 mm⁻¹
T = 173 K
0.28 × 0.25 × 0.23 mm

Data collection

STOE IPDS II two-circle-diffractometer
Absorption correction: multi-scan (MULABS; Spek, 2003 ▶; Blessing, 1995 ▶) T _min = 0.919, T _max = 0.933
8050 measured reflections
3437 independent reflections
2244 reflections with I > 2σ(I)
R _int = 0.069

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.065
S = 0.73
3437 reflections
239 parameters
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.27 e Å⁻³
Absolute structure: Flack (1983 ▶), 1430 Friedel pairs
Flack parameter: 0.27 (9)

Data collection: X-AREA (Stoe & Cie, 2001 ▶); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP (Sheldrick, 2008 ▶) and PLATON (Spek, 2003 ▶; software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809042846/om2290sup1.cif

e-65-o2828-sup1.cif^{(20.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809042846/om2290Isup2.hkl

e-65-o2828-Isup2.hkl^{(168.6KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15⋯O3ⁱ	0.95	2.45	3.123 (5)	127

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Symmetry code: (i) Inline graphic .

Acknowledgments

This work was supported by a grant from the Universidad de Antofagasta (DI-1324–06). We thank the Spanish Research Council (CSIC) for providing us with a free-of-charge licence for the CSD system. JA thanks the Universidad de Antofagasta for PhD fellowships.

supplementary crystallographic information

Comment

In recent years, the rational design of coordination polymers based on multitopic bridging ligands and metal centers represents one of the most rapidly developing fields owing to their potential as functional materials (Guo et al., 2002; Melcer et al., 2001). The use of flexible ligands in such studies has attracted increasing attention because the flexibility and conformational freedom of such ligands offer the possibility for the construction of diverse frameworks with tailored properties and functions (Bu et al., 2001; Withersby et al., 1997).

The structure of the title compound is described here as part of our work involving the study of the synthesis and structural characterization of divalent-sulfur compounds (Brito et al., 2004, 2005, 2006). The title compound is a longer analogue of 2,2'-dithiodibenzoate with the two benzoate units interconnected by a flexible –S-(CH₂)₄-S– bridge. The bridging chain moiety, –S-(CH₂)₄-S– is almost planar (r.m.s. deviation for all non-H atoms: 0.056 Å). Its mean plane forms a dihedral angle of 16.60 (7) and 5.80 (2)° with the aromatic rings. The C(sp²)-S bond lengths [1.780 (3), 1.773 (3) Å] are significantly shorter than the C(sp³)-S [1.821 (3), 1.822 (3) Å] bond lengths due to p-π conjugation, similar to that observed in 1,6-Bis(phenylsulfanyl)hexane (Awaleh et al., 2005). The torsion angles in the aliphatic segment of the title compound are all trans, indicating that the molecule is in the fully extended conformation. The supramolecular structure of the title compound depends solely upon C—H···O hydrogen bonds: there are no significant S···S nor S···O contacts present in the structure and C—H···π (arene) hydrogen bonds and aromatic π···π stacking interactions are also absent. Atom C15 in the molecule at (x,y,z) acts as a hydrogen-bond donor to the carbonyl O3 atom in the molecule at (-x + 1/2,-y,z - 1/2), thereby generating a C(14) chain (Bernstein et al., 1995) running in the [0 0 1] direction (Figure 2). The molecular stucture is stabilized by two C—H···O intramolecular hydrogen bonds (Table 1).

Experimental

The title compound was synthesized as follows: a solution of 1,4-dibromobutene (1.08 g, 5 mmol) in ethanol (10 ml) was added dropwise to a mixture of methyl thiosalicylate (1.85 g, 11 mmol), KOH (0.617 g, 11 mmol) and ethanol (10 ml). The reaction mixture was stirred for 24 h at room temperature. The precipitate was filtered off, washed with water.Yield 80%; m.p. 393–396 K. FT—IR (KBr pellets, cm^-1): ν (w, C—H of CH₃(asym.)) 2984, ν (w, C—H of CH₃(sym.)) 2842, ν (w, C—H (aliphatic chain, sym) 2947, ν (w, C—H (chain aliphatic, asym)2919, ν (s, C=O) 1703, ν (s, C—H disubstitution 1,2) 1429, ν (s, O—C(CH₃) 1252, ν (w, C—S) 749. Analysis calculated for C₂₀H₂₂O₄S_2,C 61.51, H 5.68, S 16.42%; found C 61.47, H, 5.72, S 15.32. Crystals suitable for single-crystals X-ray analysis were obtained by recrystallization from an acetonitrile solution.