5,17-Dibromo-26,28-bis­[(meth­oxy­carbon­yl)meth­oxy]-25,27-diprop­oxy-2,8,14,20-tetra­thia­calix[4]arene

Li-Jing Zhang; Ling-Ling Liu; Qi-Kui Liu; Dian-Shun Guo

doi:10.1107/S1600536812014559

. 2012 Apr 13;68(Pt 5):o1353–o1354. doi: 10.1107/S1600536812014559

5,17-Dibromo-26,28-bis[(methoxycarbonyl)methoxy]-25,27-dipropoxy-2,8,14,20-tetrathiacalix[4]arene

Li-Jing Zhang ^a, Ling-Ling Liu ^a, Qi-Kui Liu ^a, Dian-Shun Guo ^a,^*

PMCID: PMC3344486 PMID: 22590248

Abstract

The title thiacalix[4]arene derivative, C₃₆H₃₄Br₂O₈S₄, adopts an unusual pinched cone conformation with the propoxy-substituted benzene rings inclined inward [forming a dihedral angle of 33.4 (1)°] and with the brominated benzene rings bent outward, making a dihedral angle of 66.1 (1)°. In the crystal, the molecules form chains along [001] via C—H⋯S hydrogen bonds and S⋯S contacts [S⋯S = 3.492 (3) Å]. The chains are associated into bilayers through C—H⋯O hydrogen bonds, generating an R ₂ ²(10) motif.

Related literature

For general background to the chemistry of thiacalix[4]arenes, see: Shokova & Kovalev (2003 ▶); Lhoták (2004 ▶); Morohashi et al. (2006 ▶); Kajiwara et al. (2007 ▶); Guo et al. (2007 ▶). For related structures, see: Lhoták et al. (2000 ▶, 2003 ▶); Himl et al. (2005 ▶); Xu et al. (2008 ▶); Chen et al. (2010 ▶); Liu et al. (2011 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶); Hu et al. (2009 ▶). For atomic van der Waals radii, see: Bondi (1964 ▶).

Experimental

Crystal data

C₃₆H₃₄Br₂O₈S₄
M _r = 882.69
Monoclinic,
a = 16.024 (3) Å
b = 14.808 (3) Å
c = 15.872 (3) Å
β = 100.065 (3)°
V = 3708.3 (12) Å³
Z = 4
Mo Kα radiation
μ = 2.46 mm⁻¹
T = 173 K
0.38 × 0.18 × 0.13 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1999 ▶) T _min = 0.455, T _max = 0.740
19322 measured reflections
6989 independent reflections
4908 reflections with I > 2σ(I)
R _int = 0.060

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.091
S = 0.93
6989 reflections
455 parameters
H-atom parameters constrained
Δρ_max = 0.62 e Å⁻³
Δρ_min = −0.55 e Å⁻³

Data collection: SMART (Bruker, 1999 ▶); cell refinement: SAINT (Bruker, 1999 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812014559/ld2052sup1.cif

e-68-o1353-sup1.cif^{(29.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812014559/ld2052Isup2.hkl

e-68-o1353-Isup2.hkl^{(342KB, 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
C4—H4⋯S3ⁱ	0.95	2.91	3.755 (3)	149
C33—H33A⋯O7ⁱⁱ	0.98	2.58	3.551 (5)	169

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

Financial support from the National Natural Science Foundation of China (grant No. 20572064) and the Natural Science Foundation of Shandong Province (grant No. ZR2010BM022) is gratefully acknowledged.

supplementary crystallographic information

Comment

Thiacalix[4]arenes have attracted much interest because of their specific affinity, selectivity in molecular recognition, and supramolecular assembly (Shokova & Kovalev, 2003; Lhoták, 2004; Morohashi et al., 2006; Kajiwara et al., 2007; Guo et al., 2007). Numerous crystal structures of thiacalix[4]arenes uniformly substituted at the lower rim or at the upper rim are known (Lhoták et al., 2000, 2003; Himl et al., 2005). Recently, we have presented structures of several dibromo and tetrabromothiacalix[4]arene derivatives that possess four identical or four different substituents at the lower rim (Xu et al., 2008; Chen et al., 2010; Liu et al., 2011). Here we report the crystal structure of another dibromothiacalix[4]arene compound with different substituents at the lower rim – 5,17-dibromo-26,28-bis[(methoxycarbonyl)methoxy]-25,27-dipropoxy-2,8,14,20-tetrathiacalix[4]arene.

In the crystal structure of the title compound, C₃₆H₃₄Br₂O₈S₄, (Fig. 1), the thiacalix[4]arene unit adopts an unusual pinched cone conformation. Two opposite bromosubstituted phenolic rings are strongly bent outwards the thiacalix cavity with a Br···Br distance of 13.819 (3) Å [larger than that reported previously - 13.165 (2) Å (Liu et al., 2011)]. The other two opposing phenolic rings are bent inwards. The phenolic rings form dihedral angles of 26.09 (7), 65.57 (7), 40.29 (6) and 81.18 (7)° with the virtual plane defined by the four bridging S atoms.

In the packing, there are several intermolecular short contacts (Table 1). The molecules are linked into an infinite zigzag one-dimensional chain along [001] (Hu et al., 2009) by intermolecular C4—H4···S3(x, -y + 1/2, z - 1/2) hydrogen bonds, locally forming a C(8) motif (Bernstein et al., 1995) (Fig. 2). Interestingly, in such a chain all 'tails' of the molecules extend to the same orientation and a significant S···S interaction between the adjacent thiacalix[4]arenes stabilizes the motif, with a S1···S3 distance of 3.492 (3) Å (S = 1.80 Å; Bondi, 1964). Finally, these chains are packed into a complex tail-to-tail-oriented bilayer system by a combination of interchain C—H···O hydrogen bonds, giving an R₂²(10) motif.

Experimental

BrCH₂CO₂Me (0.08 ml, 0.84 mmol) was added to a suspension of 5,17-dibromo-26,28-dihydroxy-25,27-dipropoxy-2,8,14,20-tetrathiacalix[4]arene (0.080 g, 0.14 mmol) and anhydrous K₂CO₃ (0.022 g, 0.17 mmol) in dry acetone (15 ml). The resulting mixture was stirred for 3 h at 343 K and cooled to room temperature. The solvent was removed under reduced pressure. The residue was neutralized with 5% aqueous HCl and extracted with CH₂Cl₂. The organic layer was separated and washed with saturated sodium hydrogen carbonate and brine, and dried over anhydrous MgSO₄. The solvent was evaporated in vacuo and the residue was chromatographed on a silica gel column (CH₂Cl₂/petroleum ether = 1:1) to give the title compound as a white solid (yield 63%, R_f = 0.3) and another product (yield 28%, R_f = 0.45). ¹H NMR (300 MHz, CDCl₃) for the title product: δ 7.67 (s, 4H), 6.55 (d, 4H, J = 7.26 Hz), 6.46 (t, 2H, J = 7.57 Hz), 5.10 (s, 4H), 3.88 (t, 4H, J = 7.47 Hz), 3.74 (s, 6H), 1.89~1.77 (m, 4H), 1.05 (t, 6H, J = 7.39 Hz). IR (KBr pellets, cm^-1): 1763 (C=O). Single crystals suitable for X-ray diffraction analysis were obtained by slow evaporation of a solution in CH₃OH and CHCl₃ at 298 K.