5,11,17,23-Tetra-tert-butyl-25,27-bis­[2-(4-nitro­phen­oxy)eth­oxy]calix[4]arene-26,28-diol acetonitrile tetra­solvate

Jiu-Mao Yuan; Yong-Hong Gao; Jian-Ping Ma; Dian-Shun Guo

doi:10.1107/S1600536809018212

. 2009 May 20;65(Pt 6):o1336–o1337. doi: 10.1107/S1600536809018212

5,11,17,23-Tetra-tert-butyl-25,27-bis[2-(4-nitrophenoxy)ethoxy]calix[4]arene-26,28-diol acetonitrile tetrasolvate

Jiu-Mao Yuan ^a, Yong-Hong Gao ^a, Jian-Ping Ma ^a, Dian-Shun Guo ^a,^*

PMCID: PMC2969685 PMID: 21583190

Abstract

In the crystal structure of the title compound, C₆₀H₇₀N₂O₁₀·4CH₃CN, the calix[4]arene molecule adopts an open-cone conformation with two intramolecular O—H⋯O hydrogen bonds. The four benzene rings of the calix[4]arene are twisted to the mean plane defined by four methylene C atoms bridging the benzene rings, with dihedral angles ranging from 57.74 (10) to 65.99 (12)°. Two pendant nitrophenyl rings are nearly perpendicular to each other, the dihedral angle being 70.9 (3)°. The asymmetric unit of the crystal structure contains four acetonitrile solvent molecules, one of which lies in the calix cavity and makes C—H⋯π interactions and another links with the calix[4]arene via C—H⋯O hydrogen bonding. One tert-butyl group is disordered over two sets of sites, with a 0.736 (13):0.264 (13) occupancy ratio.

Related literature

For general background to the chemistry of calix[4]arenes, see: Gutsche (1998 ▶). For related crystal structures, see: Singh et al. (2004 ▶); Bolte et al. (2003 ▶); Zeng et al. (2002 ▶); Gale et al. (1998 ▶); Drew et al. (1997 ▶); Böhmer et al. (1993 ▶); Bugge et al. (1992 ▶). For C—H⋯π contacts, see: Tsuzuki et al. (2000 ▶); Umezawa et al. (1998 ▶). For inclusion complexes, see: McKervey et al. (1986 ▶).

Experimental

Crystal data

C₆₀H₇₀N₂O₁₀·4C₂H₃N
M _r = 1143.40
Triclinic,
a = 13.195 (3) Å
b = 13.388 (3) Å
c = 19.692 (5) Å
α = 71.978 (3)°
β = 84.022 (3)°
γ = 82.230 (3)°
V = 3270.5 (13) Å³
Z = 2
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 173 K
0.51 × 0.35 × 0.15 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: none
15816 measured reflections
11155 independent reflections
7114 reflections with I > 2σ(I)
R _int = 0.049

Refinement

R[F ² > 2σ(F ²)] = 0.114
wR(F ²) = 0.349
S = 1.05
11155 reflections
775 parameters
5 restraints
H-atom parameters constrained
Δρ_max = 0.78 e Å⁻³
Δρ_min = −0.64 e Å⁻³

Data collection: SMART (Bruker, 1999 ▶); cell refinement: SAINT (Bruker, 1999 ▶); 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/S1600536809018212/xu2512sup1.cif

e-65-o1336-sup1.cif^{(46KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809018212/xu2512Isup2.hkl

e-65-o1336-Isup2.hkl^{(534.4KB, 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
O1—H1⋯O3	0.82	1.99	2.802 (6)	171
O2—H2⋯O4	0.82	1.97	2.781 (4)	176
C50—H50C⋯O7ⁱ	0.96	2.59	3.487 (10)	156
C68—H68B⋯O10	0.96	2.39	3.247 (13)	148
C65—H65A⋯Cg1	0.96	2.66	3.590 (6)	163

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Symmetry code: (i) Inline graphic . Cg1 is the centroid of the C42–C47 ring.

Acknowledgments

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

supplementary crystallographic information

Comment

Calix[4]arenes have been attracting much interest because they possess a versatile three-dimensional cavity and are ideal scaffolds for the construction of supramolecular systems. In particular, the lower or upper rim of a calix[4]arene platform can be modified to achieve more sophisticated receptors with a specific affinity and selectivity for ion recognition (Gutsche, 1998). Several crystal structures of 1,3-substituted cone calix[4]arene derivatives (Singh et al., 2004; Bolte et al., 2003; Zeng et al., 2002; Gale et al., 1998; Drew et al., 1997; Böhmer et al., 1993; Bugge et al., 1992) have been described. We report here the crystal structure of a new 1,3-substituted calix[4]arene, C₆₀H₇₀N₂O₁₀.4CH₃CN, namely 5,11,17,23-tetra-tert-butyl-25,27-bis[2-(4-nitrophenoxy)ethoxy]-26,28-dihydroxycalix[4]arene acetonitrile tetrasolvate.

In the crystal structure of the title compound, as shown in Fig. 1, the molecule of the calix[4]arene adopts an open-cone conformation, in which either phenol hydroxy group links with one neighboring ethereal O atom via an intramolecular O—H···O hydrogen bond (Table 1) and one t-butyl group shows rotational disorder. The four benzene rings of the calix[4]arene are twisted to the virtual plane defined by four methylene C atoms bridging the phenolic rings with dihedral angles ranging from 57.74 (10) to 65.99 (12)°. Two pendant nitrophenyl rings are nearly perpendicular to each other, the dihedral angle being 70.9 (3)°. This conformation results in a distance of 4.005 (6) Å between diametrically opposed atoms O1 and O2, almost same as 4.289 (6) Å between O3 and O4.

There are four acetonitrile solvate molecules in the asymmetric unit of the crystal structure, one of which lies in the calix cavity with C—H···π contacts (Umezawa et al., 1998; Tsuzuki et al., 2000) and another links with the calix[4]arene via C—H···O hydrogen bonding (Table 1). The apolar end of the acetonitrile is held in the cavity, while the polar one remains outside, similar to the related cone calix[4]arene system (McKervey et al., 1986) where an acetonitrile molecule is included. The intermolecular C—H···O hydrogen bonds (Table 1) and the remaining acetonitrile molecules stabilize the molecular packing.

Experimental

To a refluxing suspension of p-tert-butylcalix[4]arene (1.112 g, 1.50 mmol) and anhydrous potassium carbonate (0.228 g, 1.65 mmol) in dry acetonitrile (15 ml) was added 2-(4-nitrophenoxy)ethyl-4-methylbenzenesulfonate (1.144 g, 3.00 mmol) in dry acetonitrile (15 ml) dropwise. The mixture was stirred and refluxed under a nitrogen atmosphere for 46 h and cooled to room temperature. The solvent was removed under reduced pressure. The residue was neutralized with diluted hydrochloric acid and extracted with dichloromethane. The organic layer was washed with saturated sodium hydrogen carbonate and brine, and dried over anhydrous magnesium sulfate. Removal of the solvent under reduced pressure, the residue was purified by flash column chromatography (silica gel, ethyl acetate/hexane/dichloromethane = 1:12:4, R_F = 1/2) to give the title compound in 88% yield as a white solid, m.p. 397–399 K. Single crystals suitable for X-ray diffraction analysis were obtained from slow evaporation of a solution in acetonitrile at 298 K.