25,26,27,28-Tetra­kis(3-bromo­benzyl­oxy)calix[4]arene

Eunji Lee; Suk-Hee Moon; Tae Ho Kim; Ki-Min Park

doi:10.1107/S1600536811022975

. 2011 Jun 18;67(Pt 7):o1716. doi: 10.1107/S1600536811022975

25,26,27,28-Tetrakis(3-bromobenzyloxy)calix[4]arene

Eunji Lee ^a, Suk-Hee Moon ^b,^*, Tae Ho Kim ^a, Ki-Min Park ^a,^*

PMCID: PMC3151756 PMID: 21837108

Abstract

In the title compound, C₅₆H₄₄Br₄O₄, the calix[4]arene unit displays the 1,2-alternate conformation with crystallograpically imposed inversion symmetry. The four phenoxy rings of the calix[4]arene unit are twisted about the mean plane defined by the four methylene C atoms bridging the benzene rings, with dihedral angles of 46.73 (6) and 66.11 (5)°. The dihedral angle between adjacent phenoxy rings is 74.75 (7)°. The two pendant bromophenyl rings on the same side of the calix[4]arene unit are nearly perpendicular to each other, with a dihedral angle of 72.85 (10)° due to an intramolecular C—H⋯π interaction. In the crystal, a Br⋯Br contact of 3.6350 (5) Å, an intermolecular C—H⋯Br hydrogen bond and an intermolecular C—H⋯π interaction are observed.

Related literature

For calix[4]arene chemistry and its applications, see: Gutsche (2008 ▶); Ikeda & Shinkai (1997 ▶). For the use of calixarenes in crystal engineering, see: Dalgrano et al. (2007 ▶). For the modification of calix[4]arenes, see: Asfari et al. (2001 ▶); Mandolini & Ungaro (2000 ▶).

Experimental

Crystal data

C₅₆H₄₄Br₄O₄
M _r = 1100.55
Monoclinic,
a = 13.4377 (8) Å
b = 10.4789 (7) Å
c = 17.1666 (12) Å
β = 103.822 (2)°
V = 2347.3 (3) Å³
Z = 2
Mo Kα radiation
μ = 3.48 mm⁻¹
T = 173 K
0.21 × 0.20 × 0.15 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) ▶ T _min = 0.529, T _max = 0.624
22506 measured reflections
5813 independent reflections
3929 reflections with I > 2σ(I)
R _int = 0.037

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.106
S = 1.02
5813 reflections
289 parameters
H-atom parameters constrained
Δρ_max = 0.63 e Å⁻³
Δρ_min = −0.91 e Å⁻³

Data collection: APEX2 (Bruker, 2006 ▶); cell refinement: SAINT (Bruker, 2006 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL and DIAMOND (Brandenburg, 1998 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811022975/wn2436sup1.cif

e-67-o1716-sup1.cif^{(22.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811022975/wn2436Isup2.hkl

e-67-o1716-Isup2.hkl^{(284.6KB, hkl)}

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

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

Cg1 and Cg2 are the centroids of the C23–C28 and C7–C12 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C15—H15B⋯Br2ⁱ	0.99	2.91	3.652 (2)	132
C17—H17⋯Cg1	0.95	2.74	3.69	175
C5—H5⋯Cg2ⁱⁱ	0.95	2.68	3.54	151

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

Acknowledgments

This research was supported by a Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (No. 2010–0022675).

supplementary crystallographic information

Comment

Calix[4]arenes are macrocycles employed widely in supramolecular chemistry (Gutsche, 2008; Ikeda & Shinkai, 1997) and crystal engineering (Dalgrano et al., 2007) because they can be easily modified by selective reactions involving the upper and/or the lower rim of the molecule (Asfari et al., 2001; Mandolini & Ungaro, 2000). Calix[4]arenes can adopt several conformations, of which the 1,2-alternate conformation is much less commonly found. For that reason, the title compound, adopting the 1,2-alternate conformation, was prepared for use as a starting material for the preparation of ligands for construction of metallo-supramolecular architectures via appropriate chemical modification at the bromine positions.

In the crystal structure of the title compound, as shown in Fig. 1, the calix[4] unit adopts an 1,2-alternate conformation, located on a crystallographic inversion centre. Therefore the asymmetric unit consists of one half-molecule. The four phenoxy rings of the calix[4]arene unit are twisted about the mean plane defined by the four methylene C atoms (C13, C14, C13ⁱ and C14ⁱ) bridging the benzene rings, with dihedral angles of 46.73 (6)° for the C1–C6 ring and 66.11 (5)° for the C7–C12 ring (symmetry code: (i) -x, -y + 2, -z + 1). The adjacent phenoxy rings make a dihedral angle of 74.75 (7)°. The two pendant bromophenyl rings on the same side of the calix[4]arene unit are nearly perpendicular to each other, with a dihedral angle of 72.85 (10)° due to the intramolecular C—H···π interaction; Cg1 is the centroid of the C23–C28 ring, H17··· Cg1 2.74 Å and C17—H17···Cg1 174.5 ° (Table 1, Fig. 1).

In the crystal structure, as shown in Fig. 2, a Br···Br contact of 3.6350 (5) Å, an intermolecular C—H···Br hydrogen bond and intermolecular C—H···π interaction are observed (Table 1). These intermolecular interactions may contribute to the stabilization of the crystal packing.

Experimental

To a refluxing suspension of calix[4]arene (2.00 g, 4.71 mmol) and caesium carbonate (7.50 g, 23.0 mmol) in dry acetone (200 ml) was added dropwise 1-bromo-3-(methylbromo)benzene (4.80 g, 19.2 mmol) in dry acetone (20 ml). The mixture was stirred and refluxed for 12 h and cooled to room temperature. The solvent was removed under reduced pressure. The residue was neutralized with 10% hydrochloric acid and extracted with dichloromethane. The organic layer was washed three times with water and dried over anhydrous magnesium sulfate. After removal of the solvent under reduced pressure, the residue was recrystallized from dichloromethane-hexane to give the title compound in 27% yield as a white solid. Single crystals suitable for X-ray diffraction were obtained by evaporation of a dichloromethane solution.