Dicyclo­hexyl­ammonium 2-methoxy­benzoate

Nenad Judaš; Tomislav Portada

doi:10.1107/S1600536808007587

. 2008 Apr 2;64(Pt 5):o774–o775. doi: 10.1107/S1600536808007587

Dicyclohexylammonium 2-methoxybenzoate

Nenad Judaš ^a,^*, Tomislav Portada ^b

PMCID: PMC2961178 PMID: 21202268

Abstract

The asymmetric unit of the title compound, C₁₂H₂₄N⁺·C₈H₇O₃ ⁻, contains one dicyclohexylammonium cation and one 2-methoxybenzoate anion. Two cations and two anions are linked together to form a four-ion cluster through a set of N—H⋯O hydrogen bonds. Weak C—H⋯O hydrogen bonds connect the clusters into chains that are stacked along the crystallographic c axis.

Related literature

For the crystal structures of dicyclohexylammonium salts of monocarboxylic acids, see: Ng et al. (1999 ▶); Ng, Naumov et al. 2001 ▶), Ng & Hook (1999 ▶); Subramanian et al. (2000 ▶). For the crystal structures of dicyclohexylammonium salts of dicarboxylic acids, see: Ballabh et al. (2005 ▶); Trivedi et al. (2005 ▶); Ng, Chantrapromma et al. (2001 ▶). For related literature, see: Zain & Ng (2007 ▶); Trivedi et al. (2004 ▶); Ng et al. (1991 ▶); Allen et al. (1987 ▶).

Experimental

Crystal data

C₁₂H₂₄N⁺·C₈H₇O₃ ⁻
M _r = 333.46
Monoclinic,
a = 9.2798 (5) Å
b = 17.7978 (9) Å
c = 12.1513 (7) Å
β = 104.720 (5)°
V = 1941.04 (18) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 (1) K
0.62 × 0.41 × 0.35 mm

Data collection

Oxford Diffraction Xcalibur CCD diffractometer
Absorption correction: none
19673 measured reflections
3789 independent reflections
2750 reflections with I > 2σ(I)
R _int = 0.042

Refinement

R[F ² > 2σ(F ²)] = 0.068
wR(F ²) = 0.175
S = 1.03
3789 reflections
225 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2003 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2003 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶), Mercury (Macrae et al., 2006 ▶), RasTop (Valadon, 2000–2003 ▶) and POV-RAY (Persistence of Vision, 2004 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808007587/wn2244sup1.cif

e-64-0o774-sup1.cif^{(19.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808007587/wn2244Isup2.hkl

e-64-0o774-Isup2.hkl^{(182KB, 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
N1—H2⋯O1	0.92 (3)	1.84 (3)	2.735 (3)	163 (2)
N1—H1⋯O2ⁱ	0.88 (2)	1.85 (3)	2.703 (2)	162 (2)
C20—H20A⋯O1ⁱⁱ	0.97	2.66	3.457 (3)	140

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

Acknowledgments

Financial support by the Ministry of Science, Education and Sport of the Republic of Croatia is gratefully acknowledged (grant Nos. 098–0982914-2935 and 119–1193079-1084).

supplementary crystallographic information

Comment

The title compound was synthesized as a model for the purposes of a workshop on parallel synthesis and combinatorial chemistry. The compound was selected because of its resemblance to dicyclohexylammonium salts of substituted cinnamic acids, that are widely known as gelators of organic fluids (Ballabh et al., 2005; Trivedi et al., 2005, Trivedi et al., 2004).

The molecular structure of the title compound is shown in Fig. 1. The asymmetric unit consist of a dicyclohexylammonium cation and a 2-methoxybenzoate anion. The carboxylate group of the anion is twisted with respect to the parent benzene ring by 65.1 (2)°. All bond lengths fall within normal ranges (Allen et al., 1987).

Two cations and two anions self-assemble into a tetrameric structural unit by two hydrogen bonds; N1—H2···O1 and N1—H1···O2ⁱ (Fig. 2, Table 1.).

Weak C20—H20···O1ⁱⁱ hydrogen bonds (Fig. 3, Table 1) link these tetrameric units into chains that are stacked together in a zipper-like manner, so as to produce narrow channels between them (Fig. 4a). The appearance of the channels is consistent with the relatively low calculated density of the title compound (1.14 g cm^-3).

The zipper-like stacking is achieved by the interdigitation of protruding benzene groups in each chain (Fig. 4 b), thus maximizing the intermolecular contacts.

Experimental

A solution of dicyclohexylamine (363 mg, 2.00 mmol) in toluene (5 ml) was added with stirring to a solution of 2-methoxybenzoic acid (304 mg, 2.00 mmol) in toluene (5 ml). The resulting solution was allowed to stand in an open beaker for several days until crystals of the title compound formed by slow solvent evaporation. The crystals were suitable for single-crystal X-ray diffraction. The compound was also analyzed by thermal methods (TG and DSC). Thermal analyses were performed on METTLER thermal analysis modules DSC823^e and TGA/SDTA851^e. The calorimetric thermogram exhibited one endothermic signal that was sharp and well defined, corresponding to the melting point of the compound. The onset temperature of the signal is T_f = 416 K with enthalpy of fusion, ΔH_fus = 37,9 kJ mol^-1. Degradation of the sample begins above 524 K.