5,11,17,23-Tetra­kis(chloro­meth­yl)-25,26,27,28-tetra­propoxycalix[4]arene

Felix Kutter; Matthias H Düker; Matthias Zeller; Vladimir A Azov

doi:10.1107/S160053681100660X

. 2011 Feb 26;67(Pt 3):o728–o729. doi: 10.1107/S160053681100660X

5,11,17,23-Tetrakis(chloromethyl)-25,26,27,28-tetrapropoxycalix[4]arene

Felix Kutter ^a, Matthias H Düker ^a, Matthias Zeller ^b, Vladimir A Azov ^a,^*

PMCID: PMC3052014 PMID: 21522470

Abstract

The title calix[4]arene, C₄₄H₅₂Cl₄O₄, displays the 1,3-alternate conformation with crystallographically imposed twofold symmetry. Four phenolic rings of the calixarene backbone are tilted into the calix cavity, making dihedral angles of 77.42 (2) and 77.71 (2)° with the plane of the four bridging methylene C atoms. Pairs of opposite aromatic rings make dihedral angles of 25.16 (3) and 24.58 (4)° with each other. In the crystal, the calixarene molecules pack with the formation of infinite columns along the b axis. The crystal packing shows a network of C—H⋯Cl contacts, which can be considered as non-classical hydrogen bonds.

Related literature

For calixarene derivatives and their applications, see: Gutsche (2008 ▶); Ikeda & Shinkai (1997 ▶). For the use of calixarenes in crystal engineering, see: Dalgrano et al. (2007 ▶). For the previous synthesis of the title compound, see: Ikeda & Shinkai (1994a ▶). For its application in the formation of nanotubes, see: Ikeda & Shinkai (1994b ▶). For reviews on weak non-classical hydrogen bonding, see: Desiraju & Steiner (1999 ▶); Steiner (2002 ▶); Desiraju (2005 ▶).

Experimental

Crystal data

C₄₄H₅₂Cl₄O₄
M _r = 786.66
Monoclinic,
a = 23.104 (3) Å
b = 11.5871 (15) Å
c = 17.618 (2) Å
β = 117.655 (2)°
V = 4177.7 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.32 mm⁻¹
T = 100 K
0.49 × 0.31 × 0.15 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.658, T _max = 0.746
15796 measured reflections
6176 independent reflections
5280 reflections with I > 2σ(I)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.119
S = 0.97
6176 reflections
235 parameters
H-atom parameters constrained
Δρ_max = 0.84 e Å⁻³
Δρ_min = −1.05 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: CRYSTALS, enCIFer (Allen et al., 2004 ▶) and publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053681100660X/rk2266sup1.cif

e-67-0o728-sup1.cif^{(18.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681100660X/rk2266Isup2.hkl

e-67-0o728-Isup2.hkl^{(308.3KB, 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
C22—H222⋯Cl25ⁱ	0.97	2.90	3.786 (1)	153
C23—H231⋯Cl26ⁱⁱ	0.97	2.90	3.557 (2)	127

Open in a new tab

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

Acknowledgments

We are grateful to Dr C. M. L. Vande Velde (Karel de Grote University College, Antwerp, Belgium) and Dr D. Watkin (University of Oxford) for helpful discussions. MHD is grateful to BFK NaWi, University of Bremen, for financial support. The X-ray diffractometer was funded by NSF grant 0087210, Ohio Board of Regents grant CAP-491 and Youngstown State University.

supplementary crystallographic information

Comment

Calixarenes, a family of macrocyclic compounds, have shown to be superb molecular scaffolds for the construction of macromolecular and supramolecular architectures (Gutsche, 2008; Ikeda & Shinkai, 1997). Calix[4]arenes can adopt several conformations, of which the cone conformation is the most commonly employed one. Due to their bowl shape and ease of preparation, they are employed widely in supramolecular chemistry and crystal engineering (Dalgrano et al., 2007) for preparation of species and materials suitable for molecular encapsulation. The 1,3–alternate conformation of calix[4]arenes is much less commonly used. The title compound and its derivatives were previously synthesized (Ikeda & Shinkai, 1994a) to study binding of metal cations in solution, as well as for preparation of calixarene–based nanotubes (Ikeda & Shinkai, 1994b).

The molecule of the title compound is shown in Fig. 1. The calix[4]arene bowl adopts the 1,3–alternate conformation around a twofold symmetry axis; for that reason, the IUPAC numbering scheme for calix[4]arenes could not be applied. All bond lengths and angles may be considered normal. Four phenolic rings are pitched into the calix cavity, as defined by the angles, which the aromatic rings make with the plane of the four bridging methylenes (C1–C7–C1ⁱ–C7ⁱ): 77.42 (2)° (ring C2–6, C14) and 77.71 (2)° (ring C8–13), respectively (symmetry code: (i) -x+1, y, -z+3/2). Two pairs of opposite aromatic rings show interplanar angles of 25.16 (3)° (ring C2–6, C14) and 24.58 (4)° (ring C8–13), respectively. Four propyl chains point outside the cavity and adopt an anti conformation for all their bonds. Four chlorine atoms are also pointing outside from the calix cavity.

Several non–classical intermolecular weak hydrogen bonds are present in the structure (Desiraju & Steiner, 1999; Steiner, 2002; Desiraju, 2005). Details of the packing interactions are given in Table 1. Molecules pack into infinite columns along the b axis. Two short C23–H231···Cl26ⁱⁱⁱ (symmetry code: (iii) x, y-1, z) contacts (2.90Å), parallel to the b axis, link molecules with each other (Fig. 2). Along the c axis, the molecules are interconnected side–to–side through pairs of C22–H222···Cl25ⁱⁱ (symmetry code: (ii) x, -y, z - 1/2) interactions (2.90Å, Fig. 3). In both cases, hydrogen atoms of the C22–24 propyl chains serve as H–bond donors. When viewed along the b axis, calixarene backbones form infinite channels with a shortest distance of 8.8090 (13)Å between the two neighboring channel centers (Fig. 2).

Experimental

A solution of 25,26,27,28–tetrapropoxycalix[4]arene (0.108 g, 0.169 mmol), paraformaldehyde (0.115 g, 3.83 mmol), glacial acetic acid (1.3 ml), and conc. H₃PO₄ (1.3 ml) in dioxane (5 ml) was stirred for 2 h at 353 K. After addition of conc. HCl (1.3 ml, 16.1 mmol) the solution was stirred for additional 16 h at 353 K. The mixture was concentrated under vacuum up to ca 3 ml, poured into ice/water (100 ml) and extracted with CH₂Cl₂ (3×20 ml). The combined organic phases were washed with water and brine, dried (Na₂SO₄), and evaporated to dryness. The resulting oil was dissolved in a small amount of CH₂Cl₂ and MeOH was slowly added. The precipitate was filtered off, washed with cold MeOH, dried under vacuum, and purified by column chromatography to yield 80 mg (0.102 mmol, 60%) of product as a white crystalline powder.

R_f = 0.41 (CH₂Cl₂/PE, 1:1). Mp: 562–565 K (CHCl₃/heptane, decomp.); Lit: 556–558 K (Ikeda & Shinkai, 1994a). ¹H NMR (200 MHz, CDCl₃): δ 1.02 (t, J = 7.5 Hz, 12 H), 1.78 (tq, J = 7.2, 7.5 Hz, 8 H), 3.55 (s, 8 H), 3.63 (t, J = 7.2 Hz, 8 H), 4.43 (s, 8 H), 7.01 (s, 8 H). ¹³C NMR (50 MHz, CDCl₃): δ 10.6, 23.8, 36.0, 46.7, 73.8, 129.8, 130.5, 133.3, 156.7. HR–MS (EI, 70 eV): m/z 784.25829 (M⁺, C₄₄H₅₂Cl₄O₄⁺, calcd. 784.26197).

X–ray quality crystals were grown by slow evaporation of a chloroform/heptane solution and appeared as large (up to 1–2 mm) transparent blocks.