5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetra­kis[2-(2-chloro­ethoxy)eth­oxy]-2,8,14,20-tetra­sulfonyl­calix[4]arene

Ling Hu; Yang Liu; Jiang-Ping Ma; Dian-Shun Guo

doi:10.1107/S1600536809002591

. 2009 Jan 28;65(Pt 2):o385–o386. doi: 10.1107/S1600536809002591

5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrakis[2-(2-chloroethoxy)ethoxy]-2,8,14,20-tetrasulfonylcalix[4]arene

Ling Hu ^a, Yang Liu ^a, Jiang-Ping Ma ^a, Dian-Shun Guo ^a,^*

PMCID: PMC2968348 PMID: 21581981

Abstract

Molecules of the title compound, C₅₆H₇₆Cl₄O₁₆S₄, have crystallographic C ₂ symmetry and adopt a 1,3-alternate conformation where the four –OCH₂CH₂OCH₂CH₂Cl groups are located alternately above and below the virtual plane (R) defined by the four bridging S atoms. The dihedral angles between the plane (R) and the phenolic rings are 72.85 (7) and 74.57 (7)°. An unusual 24-membered macrocyclic ring is formed in the crystal structure with an array of eight intramolecular C—H⋯O hydrogen bonds between the ether arm H atoms and the sulfonyl O atoms. In the supramolecular structure, the molecular components are linked into infinite zigzag one-dimensional chains by a combination of four intermolecular C—H⋯O hydrogen bonds, forming R ₂ ²(13), R ₂ ²(16), R ₂ ²(21) and R ₂ ²(26) ring motifs. These chains are augmented into a wave-like two-dimensional network by weak C⋯O interactions. One tert-butyl group shows rotational disorder, and one CH₂CH₂Cl group is disordered over two orientations; the site-occupation factors are 0.756 (6) and 0.244 (6) for the two tert-butyl groups, and 0.808 (3) and 0.192 (3) for the two CH₂CH₂Cl units.

Related literature

For general background on the chemistry of thiacalix[4]arene derivatives, see: Shokova & Kovalev (2003 ▶); Lhoták (2004 ▶); Morohashi et al. (2006 ▶). For related crystal structures, see: Mislin et al. (1998 ▶, 1999 ▶); Akdas et al. (1999 ▶, 2000 ▶); Lhoták et al. (2002 ▶); Horiuchi et al. (2007 ▶); Xu et al. (2008 ▶). For the synthesis of sulfonylcalix[4]arene derivatives, see: Iki et al. (1998 ▶); Guo et al. (2007 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For C⋯O short contacts, see: Manoj et al. (2007 ▶). For atomic radii, see: Bondi (1964 ▶).

Experimental

Crystal data

C₅₆H₇₆Cl₄O₁₆S₄
M _r = 1275.21
Monoclinic,
a = 22.496 (2) Å
b = 16.0372 (15) Å
c = 19.8646 (19) Å
β = 120.355 (1)°
V = 6184.1 (10) Å³
Z = 4
Mo Kα radiation
μ = 0.39 mm⁻¹
T = 173 (2) K
0.41 × 0.28 × 0.24 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 1999 ▶) T _min = 0.856, T _max = 0.912
15381 measured reflections
5442 independent reflections
4709 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.058
wR(F ²) = 0.166
S = 1.09
5442 reflections
402 parameters
27 restraints
H-atom parameters constrained
Δρ_max = 1.30 e Å⁻³
Δρ_min = −0.80 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 datablocks I, global. DOI: 10.1107/S1600536809002591/zl2171sup1.cif

e-65-0o385-sup1.cif^{(29.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809002591/zl2171Isup2.hkl

e-65-0o385-Isup2.hkl^{(266.6KB, 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
C11—H11A⋯O1ⁱ	0.99	2.48	3.232 (4)	133
C11—H11B⋯O3	0.99	2.51	3.103 (4)	118
C20—H20B⋯O1ⁱⁱ	0.98	2.57	3.377 (5)	139
C21—H21C⋯O8ⁱⁱⁱ	0.98	2.60	3.462 (6)	146
C25—H25A⋯O2	0.99	2.58	3.099 (4)	113
C25—H25B⋯O4	0.99	2.45	3.217 (4)	134

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

Acknowledgments

Financial support from the National Natural Science Foundation of China (grant No. 20572064) and the Natural Science Foundation of Shandong Province (grant No. Y2006B30) is gratefully acknowledged.

supplementary crystallographic information

Comment

Thiacalix[4]arenes have attracted considerable interest in recent years as useful scaffolds for highly organized ionophores (Shokova & Kovalev, 2003; Lhoták, 2004; Morohashi et al., 2006; Guo et al., 2007). Compared with classical calix[4]arenes, the presence of four bridging S atoms results in a differing complexation ability, and a diverse cavity and conformational behavior. Moreover, by virtue of the sulfide function, thiacalix[4]arenes can undergo unique transformations that are not applicable to the classical calix[4]arenes, the most important of which is oxidation to sulfinyl and sulfonyl functions. All four sulfide groups of thiacalix[4]arenes, for instance, can be easily converted to sulfones by a small excess amount of an oxidant such as hydrogen peroxide or sodium perborate in an organic acid solvent (Iki et al., 1998; Mislin et al., 1998). A number of crystal stuctures of sulfonyl derivatives of thiacalix[4]arenes (Mislin et al., 1998; Akdas et al., 2000; Lhoták et al., 2002; Horiuchi et al., 2007) have been described. We now present the crystal structure of a new sulfonyl derivative thiacalix[4]arene, 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis[2-(2-chloroethoxy)ethoxy]-2,8,14,20-tetrasulfonylcalix[4]arene.

The title sulfonylcalix[4]arene derivative is shown in Fig. 1. It was found to adopt a 1,3-alternate conformation with O atoms of the sulfones pointing outward. The main geometric parameters of the title molecule are comparable to those reported for the similar structures (Mislin et al., 1998; Akdas et al., 2000) and most bond lengths and angles are consistent with the values presented for 1,3-alternate-5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakismethyl-2,8,14,20-tetrasulfonylcalix[4]arene (Mislin et al., 1998). The sulfonylcalix[4]arene shape of the title compound can be characterized by the values of the dihedral angles between the phenolic rings and the plane (R) defined by the four bridging S atoms. The dihedral angles between the plane (R) and the aromatic rings are 74.57 (7) and 72.85 (7)°, respectively. Actually, the title molecule has a pseudo 4-fold rotation-reflection (S₄) axis. Consistent with this symmetry, the adjacent phenyl rings lie above and below the plane (R), and interplanar angles of the opposing aromatic rings are 34.31 (8) and 38.86 (14)°. The pseudo S₄ symmetry also reasonably depicts the almost parallel orientation of the four ether arms above and below the plane (R). The separations between diametrically located ethereal O5 and O5ⁱ, O7 and O7ⁱ [Symmetry code: (i) -x + 1, y, -z + 3/2] are 4.660 (4) and 4.347 (4) Å, respectively. In the crystal packing, 1,3-alternate molecules are packed along the b axis, forming a type of a beautiful nanotubular array extending in the b direction (Fig. 3). Such a packing was found in the cases of several 1,3-alternate thiaclix[4]arene derivatives (Akdas et al., 1999, 2000; Guo et al., 2007; Xu et al., 2008).

Although no conventional hydrogen bonds are found, various intra- and intermolecular C—H···O hydrogen bonds exist in the crystal structure (Table 1). Interestingly, an unusual 24-membered macrocyclic ring is formed by an array of eight intramolecular C—H···O hydrogen bonds between the sulfonyl O atoms and the ether arm protons closer the phenolic rings, which stabilize the 1,3-alternate conformation (Fig. 4). In this macrocyclic ring, both O atoms of each sulfonyl group act as a hydrogen-bond acceptor, via H, to two C atoms belonging to both adjacent ether arms, respectively. A similar hydrogen bonding array was observed in the structure of the related compound p-tert-butyltetrasulfinylcalix[4]arene, however, it is formed with only four intramolecular O—H···O hydrogen bonds between the OH and SO groups (Mislin, et al., 1999). On the other hand, in the supramolecular structure, infinite zigzag one-dimensional chains are generated by a combination of four intermolecular C—H···O hydrogen bonds, locally forming different ring motifs: two R₂²(13), one R₂²(16), two R₂²(21), and one R₂²(26) (Bernstein et al., 1995), and making a distorted capsule at each link in the chain (Fig. 4). These motifs arise from atoms C20 and C21 at (x, y, z) and (-x + 1, -y + 1, -z + 1) in neighboring molecules that act as hydrogen-bond donors, respectively, via H20B, to atoms O1 at (-x + 1, -y + 1, -z + 1) and (x, y, z), via H21C, to atoms O8 at (x, -y + 1, z - 1/2) and (-x + 1, y, -z + 3/2). The zigzag chains are linked into wave-like two-dimensional networks by the C···O weak interactions (Manoj et al., 2007) between C10^iv [symmetry code: (iv) – x + 3/2, – y + 3/2, –z + 2] and O3. The C10^iv···O3 distance is 3.143 (4) Å, less than the sum of the van der Waals radii for C and O atoms (C = 1.70 Å, O = 1.52 Å; Bondi, 1964).

Experimental

For the synthesis of the title compound, to a solution of 1,3-alternate-5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis[2-(2-chloroethoxy)ethoxy]thiacalix[4]arene, prepared according to the published precedure (Guo et al., 2007), (0.200 g, 0.174 mmol) in CHCl₃ (10 ml) and CF₃CO₂H (1.50 ml) was added 30% H₂O₂ (0.90 ml, 7.840 mmol). The resulting mixture was stirred at 298 K for 50 h, and neutralized with a saturated aqueous solution of NaHCO₃. The organic layer was separated and washed with brine, and dried over anhydrous MgSO₄. Removal of the solvent under reduced pressure gave the title compound as a white solid (yield 95%) by recrystallization from CH₂Cl₂/CH₃OH. ¹H NMR (300 MHz, CDCl₃): δ 8.38 (s, 8H), 4.58 (t, 8H, J = 5.67 Hz), 3.84 (t, 16H, J = 5.98 Hz), 3.71 (t, 8H, J = 5.83 Hz), 1.40 (s, 36H). IR (KBr pellets, cm^-1): 1304, 1137. Single crystals of the title molecule suitable for X-ray diffraction analysis were obtained by slow evaporation of a solution in CH₂Cl₂ and CH₃OH at 273 K.