25,26,27,28-Tetra­butoxy-5,11,17,23-tetra-tert-butyl­calix[4]arene chloro­form tetra­solvate dihydrate

Zhengyi Li; Dinghao Yuan; Haitao Xi; Xiaoqiang Sun

doi:10.1107/S160053680902217X

. 2009 Jun 27;65(Pt 7):o1697. doi: 10.1107/S160053680902217X

25,26,27,28-Tetrabutoxy-5,11,17,23-tetra-tert-butylcalix[4]arene chloroform tetrasolvate dihydrate

Zhengyi Li ^a, Dinghao Yuan ^b, Haitao Xi ^a, Xiaoqiang Sun ^a,^*

PMCID: PMC2969488 PMID: 21582951

Abstract

The title compound, C₆₀H₈₈O₄·4CHCl₃·2H₂O, is the alkylated product of 5,11,17,23-tetra-tert-butylcalix[4]arene. It adopts a distorted cone conformation which leads to an open cavity. All the phenolic rings are tilted so that their tert-butyl groups are pitched away from the calix cavity. Two opposite aromatic rings are close to being perpendicular to one another [dihedral angle 85.0 (2)°], while the other pair of opposite rings is almost parallel [dihedral angle 8.1 (2)°], and adjacent phenolic rings are almost perpendicular [dihedral angles 82.4 (1) or 87.9 (1)°]. In the crystal, the water molecule and calixarene interact by way of O—H⋯O hydrogen bonds.

Related literature

For calix[4]arene derivatives as supramolecular building blocks, see: Böhmer (1995 ▶); Homden & Redshaw (2008 ▶). For related structures, see: Rathore et al. (2000 ▶) and Brusko et al. (2005 ▶). For details of the synthesis, see: Matthews et al. (1999 ▶).

Experimental

Crystal data

C₆₀H₈₈O₄·4CHCl₃·2H₂O
M _r = 1386.81
Orthorhombic,
a = 23.697 (6) Å
b = 13.682 (6) Å
c = 25.402 (11) Å
V = 8236 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.44 mm⁻¹
T = 291 K
0.26 × 0.22 × 0.20 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.894, T _max = 0.917
30239 measured reflections
8098 independent reflections
5524 reflections with I > 2σ(I)
R _int = 0.036

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.117
S = 1.06
8098 reflections
396 parameters
H-atom parameters constrained
Δρ_max = 0.82 e Å⁻³
Δρ_min = −0.73 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680902217X/ez2170sup1.cif

e-65-o1697-sup1.cif^{(28.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680902217X/ez2170Isup2.hkl

e-65-o1697-Isup2.hkl^{(396.3KB, 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
O3—H3C⋯O4	0.85	1.52	2.149 (8)	127
O5—H5C⋯O5ⁱ	0.85	1.74	2.299 (13)	121

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Symmetry code: (i) Inline graphic .

Acknowledgments

We gratefully acknowledge financial support from the Natural Science Foundation of China (No. 20872051).

supplementary crystallographic information

Comment

Derivatives of calix[4]arene, as one of the most important supramolecular building blocks, are useful in ion and metal complexation because they form suitable scaffolds for the development of new bulky and structurally well defined ligands (Böhmer, 1995; Homden & Redshaw 2008). As an important approach to obtain functionalized calixarenes, alkylation of the phenolic hydroxyl groups on the lower rim of the calixarene has been widely explored. The crystal structures of propyl (Rathore et al., 2000) and pentyl (Brusko et al., 2005) alkylated calix[4]arene have been reported. We herein present the structure of the tetrabutyl substituted calix[4]arene (Fig. 1).

The title compound adopts a distorted cone conformation with a small cavity. All phenolic rings are tilted so that their tert-butyl groups are pitched away from the calix cavity, as defined by the angles which the aromatic rings make with the plane of the four bridging CH₂ moieties (C29, C30, C29A and C30A) which link them, viz. 94.0 (3)° (C1–C6 or C1A–C6A) and 132.5 (1)° (C15–C20 or C15A–C15A). Two opposite aromatic rings (C15–C20 and C15A–C20A) are close to being perpendicular to one another (dihedral angle 85.0 (2)°) while the other pair of opposite phenolic rings (C1–C6 and C1A–C6A) are almost parallel (dihedral angle 8.1 (2)°), and the adjacent phenolic rings are almost perpendicular (dihedral angles 97.6 (1)° or 92.1 (1)°).

Experimental

NaH (0.96 g, 40 mmol) and DMF (20 ml) were added to a suspension of 5,11,17,23-tetra(tert-butyl)calix[4]arene (3.25 g, 5 mmol) in DMF (30 ml) under argon. The suspension was stirred for 1 h, and then 1-bromobutane (5.48 g, 40 mol) was added. Stirring was continued at room temperature for 2 d. Water (100 ml) was added and the precipitate formed collected by filtration. The solid was dissolved in chloroform and washed with 15% HCl and water. The organic layer was dried and the solvent evaporated. Precipitation from chloroform/methanol gave the title compound as a white solid with sufficient purity (68% yield). Single crystals suitable for X-ray diffraction were obtained by evaporation of an methanol-chloroform solution.