Tetra­butyl­ammonium 4-hy­droxy­benzoate dihydrate

Yuan Yang; Yunxia Yang

doi:10.1107/S1600536811022823

. 2011 Jun 18;67(Pt 7):o1703. doi: 10.1107/S1600536811022823

Tetrabutylammonium 4-hydroxybenzoate dihydrate

Yuan Yang ^a, Yunxia Yang ^b,^*

PMCID: PMC3152085 PMID: 21837099

Abstract

In the title compound, (n-C₄H₉)₄N⁺·C₇H₅O₃ ⁻·2H₂O, the carboxylate group is twisted slightly out of the plane of the attached benzene ring, the two C—C—C—O torsion angles being −8.9 (2) and −10.7 (2)°. The anion interacts with two water molecules through several O—H⋯O hydrogen bonds, forming wide ribbons along the a axis constructed from two anion–water chains. These ribbons are contained between unclosed diamond-like (16.2 × 15.0 Å) channels constructed by four rows of tetrabutylammonium cations, which are arranged along the [011] and [01 Inline graphic ] directions.

Related literature

For related structures of the p-hydroxybenzoate anion with different cations, see: Marsh & Spek (2001 ▶); Yang et al. (2010 ▶).

Experimental

Crystal data

C₁₆H₃₆N⁺·C₇H₅O₃ ⁻·2H₂O
M _r = 415.60
Monoclinic,
a = 10.3679 (1) Å
b = 14.9648 (2) Å
c = 16.1851 (2) Å
β = 93.128 (1)°
V = 2507.43 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 296 K
0.49 × 0.43 × 0.20 mm

Data collection

Bruker SMART APEX diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.964, T _max = 0.985
20944 measured reflections
5869 independent reflections
4619 reflections with I > 2σ(I)
R _int = 0.018

Refinement

R[F ² > 2σ(F ²)] = 0.052
wR(F ²) = 0.143
S = 1.03
5869 reflections
265 parameters
7 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.54 e Å⁻³
Δρ_min = −0.52 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/S1600536811022823/fj2432sup1.cif

e-67-o1703-sup1.cif^{(23.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811022823/fj2432Isup2.hkl

e-67-o1703-Isup2.hkl^{(287.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811022823/fj2432Isup3.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—H1⋯O2Wⁱ	0.87 (1)	1.75 (1)	2.6125 (17)	174 (2)
O1W—H1WA⋯O2ⁱⁱ	0.86	1.92	2.7660 (18)	168
O1W—H1WB⋯O2Wⁱⁱ	0.85	2.22	2.987 (2)	150
O2W—H2WB⋯O3	0.85	1.80	2.6431 (16)	171
O2W—H2WA⋯O2ⁱⁱ	0.85	1.88	2.7195 (19)	173

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

Acknowledgments

We thank the Science Technology Foundation of Guizhou (No. [2009] 2266) and the Doctoral Foundation of Guizhou Normal University for supporting this study.

supplementary crystallographic information

Comment

p-Hydroxybenzoic acid, which can be regarded as a planar aromatic molecule that can form various hydrogen bonds through its different functional groups, 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). Herein we report the crystal structure of tetrabutylammonium p-hydroxybenzoate dihydrate, (n-C₄H₉)₄N⁺.C₇H₅O₃^-.2H₂O, in which the carboxyl group of p-hydroxybenzoate anion retorts a small angle of 10.01 (8)° with respect to the phenyl ring and two C—O bonds of the carboxyl group tend to be average (1.264 (2) Å and 1.2553 (18) Å) for the elimination of the proton. The anion makes full use of two independent water molecules to form various O—H···O hydrogen bonds to generate the wide hydrogen-bonded ribbon along the a axis (Fig. 2). In addition, four neighboring tetrabutylammonium cations construct un-closed diamond-like channels to contain the hydrogen-bonded ribbons to generate the final stable structure (Fig. 3). Obviously, water molecules, as a kind of linking unit, play an important role in constructing this structure.

Experimental

p-Hydroxybenzoic acid (0.25 mmol, 0.035 g) was dissolved in a water-ethanol (50:100 v/v) mixture and a 25% aqueous solution of tetrabutylammonium hydroxide was added according to the molar ratio of 1:3 of acid to base. Colorless block crystals separated after several weeks.