Tetra­ethyl­ammonium 4-hy­droxy­benzoate monohydrate

Heping Li; Pei Liu; Yunxia Yang

doi:10.1107/S1600536811024044

. 2011 Jun 25;67(Pt 7):o1788. doi: 10.1107/S1600536811024044

Tetraethylammonium 4-hydroxybenzoate monohydrate

Heping Li ^a, Pei Liu ^a, Yunxia Yang ^b,^*

PMCID: PMC3152065 PMID: 21837161

Abstract

In the title compound, C₈H₂₀N⁺·C₇H₅O₃ ⁻·H₂O, the carboxylate group is slightly out of the plane of the parent benzene ring, the C—C—C—O torsion angles being 2.3 (2) and 2.0 (2)°. The carboxylate group and the hydroxy group form O—H⋯O hydrogen bonds, generating a head-to-tail chain along the b axis. Neighbouring hydrogen-bonded chains are linked by the water molecule, generating two independent O—H⋯O donor hydrogen bonds. The carboxylate group thus constructs a hydrogen-bonded host layer parallel to (10 Inline graphic ). The tetraethylammonium cation is contained between these layers, forming a sandwich-like structure with an approximate interlayer distance of 10.03 Å.

Related literature

p-Hydroxybenzoic acid has been found to interact with varied cations, such as decyl(trimethyl)ammonium and hexamethonium, to form different crystal structures, see: Marsh & Spek (2001 ▶); Yang et al. (2010 ▶).

Experimental

Crystal data

C₈H₂₀N⁺·C₇H₅O₃ ⁻·H₂O
M _r = 285.38
Monoclinic,
a = 9.6082 (10) Å
b = 16.2610 (16) Å
c = 10.4478 (10) Å
β = 96.378 (1)°
V = 1622.2 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 296 K
0.66 × 0.37 × 0.20 mm

Data collection

Bruker SMART APEX diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.947, T _max = 0.984
7411 measured reflections
3774 independent reflections
2730 reflections with I > 2σ(I)
R _int = 0.015

Refinement

R[F ² > 2σ(F ²)] = 0.055
wR(F ²) = 0.181
S = 1.06
3774 reflections
182 parameters
4 restraints
H-atom parameters constrained
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811024044/fj2433sup1.cif

e-67-o1788-sup1.cif^{(19KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811024044/fj2433Isup2.hkl

e-67-o1788-Isup2.hkl^{(185KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811024044/fj2433Isup3.cml

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—H1A⋯O3ⁱ	0.86	1.74	2.5984 (16)	175
O1W—H1WA⋯O3ⁱⁱ	0.85	2.04	2.850 (2)	161
O1W—H1WB⋯O2ⁱⁱⁱ	0.85	1.94	2.781 (2)	169

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

Acknowledgments

We thank Northwest Normal University for supporting this study.

supplementary crystallographic information

Comment

p-Hydroxybenzoic acid has been found to interact with varied cations, such as decyl(trimethyl)ammonium and hexamethonium, to form different crystal structures (Marsh et al., 2001; Yang et al., 2010). In the asymmetric unit of the title compound, (C₂H₅)₄N⁺.C₇H₅O₃^-.H₂O, there exist one p-hydroxybenzoate anion, in which the carboxyl group distorts a small angle with respect to the phenyl ring which has a mean deviation from plane of 0.0041 Å (the related torsion angles are 2.3 (2)° and 2.0 (2)° respectively), one water molecule and one tetraethylammonium cation (Fig. 1). With the help of the water molecule, the hydrogen-bonded chains of p-hydroxybenzoate anions extending along the [010] direction are connected with various O—H···O interactions to generate the hydrogen-bonded host layers (Fig. 2), which are parallel to the (101) plane and can accommodate the guest species of tetraethylammonium cations to form the final packing structure (Fig. 3). Obviously, water molecule, as a compensate host molecule, plays an important role in generating the hydrogen-bonded layer structure.

For the related crystal structures of p-hydroxybenzoic acid and different cations, see: Marsh et al., (2001), Yang et al., (2010).

Experimental

p-Hydroxybenzoic acid (0.25 mmol, 0.035 g) was dissolved in small amount of water-ethanol (50:100 v/v) mixture and a 25% aqueous solution of tetraethylammonium hydroxide was added to neutralize the acid. Colorless block crystals separated after several weeks.