Bis­(2-hy­droxy­eth­yl)ammonium 2-bromo­phenolate

Kamentheren Padayachy; Manuel A Fernandes; Helder M Marques; Andreas Lemmerer; Alvaro S de Sousa

doi:10.1107/S1600536812033752

. 2012 Aug 1;68(Pt 9):o2610. doi: 10.1107/S1600536812033752

Bis(2-hydroxyethyl)ammonium 2-bromophenolate

Kamentheren Padayachy ^a, Manuel A Fernandes ^a, Helder M Marques ^a, Andreas Lemmerer ^a, Alvaro S de Sousa ^a,^*

PMCID: PMC3435641 PMID: 22969514

Abstract

In the crystal structure of the 1:1 title salt, C₄H₁₂NO₂ ⁺·C₆H₄BrO⁻, hydrogen-bonding interactions originate from the ammonium cation, which adopts a syn conformation. A gauche relationship between the C—O and C—N bonds of the 2-hydroxyethyl fragments also facilitates O—H⋯O interactions of bis(2-hydroxyethyl)ammonium cation chains to phenolate O atoms. The resulting double-ion chains along [100] are further linked by N—H⋯O interactions, forming chains parallel to [110].

Related literature

For structures of related 2-haloethylammonium salts and properties of these salts, see: Cody (1981 ▶); Cody & Strong (1980 ▶); Prout et al. (1988 ▶); Castellari & Ottani (1995 ▶); de Sousa et al. (2010a ▶,b ▶); Larsen et al. (2005 ▶); Mootz et al. (1989 ▶). For graph-set motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₄H₁₂NO₂ ⁺·C₆H₄BrO⁻
M _r = 278.15
Monoclinic,
a = 8.0592 (1) Å
b = 7.6653 (1) Å
c = 9.7659 (2) Å
β = 107.250 (1)°
V = 576.16 (2) Å³
Z = 2
Mo Kα radiation
μ = 3.56 mm⁻¹
T = 173 K
0.48 × 0.21 × 0.20 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: gaussian (XPREP; Bruker, 2005 ▶) T _min = 0.280, T _max = 0.537
11689 measured reflections
2784 independent reflections
2638 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.018
wR(F ²) = 0.042
S = 1.05
2784 reflections
149 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.28 e Å⁻³
Absolute structure: Flack (1983 ▶), 1290 Friedel pairs
Flack parameter: −0.012 (5)

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT-NT (Bruker, 2005 ▶); data reduction: SAINT-NT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812033752/bh2446sup1.cif

e-68-o2610-sup1.cif^{(20KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812033752/bh2446Isup2.hkl

e-68-o2610-Isup2.hkl^{(133.9KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812033752/bh2446Isup3.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
O2—H2⋯O1	0.83 (2)	1.83 (2)	2.6393 (16)	165 (2)
O3—H3⋯O2ⁱ	0.84	1.87	2.7010 (18)	171
N1—H1A⋯O1ⁱⁱ	0.969 (18)	1.789 (19)	2.738 (2)	165.7 (16)
N1—H1B⋯O1	0.93 (2)	1.91 (2)	2.8259 (19)	169 (2)

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

Acknowledgments

This work was funded in part by a grant through the Department of Science and Technology/National Research Foundation South Africa Research Chairs initiative to HMM.

supplementary crystallographic information

Comment

The molecular structure (Fig. 1) of the 1:1 salt of 2-bromophenol with diethanolamine (DEA) is reported. Our interest in studying DEA is aimed at developing amino alcohols as supramolecules in a crystal engineering strategy, for template self-assembly of these compounds in supramolecular structures. Directional hydrogen-bonding patterns associated with DEA have labeled this compound a potential supramolecule. It is known to aggregate into tubular columns (Mootz et al., 1989); the behaviour is emulated by C— and N—alkylated derivatives (de Sousa et al., 2010a,b). Specific O—H···O interactions of the 2-hydroxyalkyl groups contribute significantly towards tubular aggregation in alkylated derivatives of this compound. These hydrogen bonds also feature prominently in salts of DEA elucidating binding modes of thyroid hormones to transport proteins (Cody, 1981; Cody & Strong, 1980; Prout et al., 1988); the template synthesis of heterometallic wheels (Larsen et al., 2005); and in studies aimed at correlating structural and pharmacological properties of anti-inflammatory drugs (Castellari & Ottani, 1995).

O—H···O hydrogen bonds are highly influential in the molecular structure reported here for the 2-bromophenol (1:1) salt with DEA. The unitary level C(8) chain (Bernstein et al., 1995), described by O3—H3···O2 hydrogen bonds along [100], defines the backbone of the crystal structure (Fig. 2 and Table 1). In these chains syn conformations of the bis(2-hydroxyethyl) ammonium cations enjoy gauche relationships between C—O and C—N bonds, enabling further O—H···O and N—H···O hydrogen bonds of this supramolecular synthon. Hydroxyethyl O atom O2 acts as a weakly bifurcated H-donor, via H2, to phenolate O1 and Br1 atoms (Table 1). The hydrogen bonding array of the double-ion pair is completed by the N1—H1B···O1 interaction involving the ammonium N1 atom acting as a hydrogen donor, via H1B, to the phenolate oxygen atom O1. The combined O2—H2···O1 and N1—H1B···O1 interactions describe a R₂¹(7) ring motif (Fig. 2) at the binary level (Bernstein et al., 1995). Chains of double-ion pairs along [100] are linked by N1—H1A···O1 interactions (Table 1) to form layers parallel to the ab plane (Fig. 3). Within these layers N—H···O interactions define C₂¹(4) and C₂¹(7) motifs along [010] (Fig. 4) when combined with interactions N1—H1B···O1 and O2—H2···O1, respectively.

Experimental

Diethanolamine (0.501 g, 4.8 mmol) was stirred in 20 ml of dimethylformamide. To this solution, sodium carbonate (0.504 g, 4.75 mmol) and 2-bromophenol (0.823 g, 4.76 mmol) was added with continuous stirring. The reaction mixture was allowed to stir for an additional 24 hours under ambient conditions. The mixture was filtered and the solvent removed under reduced pressure, to yield a clear viscous oil that crystallized upon standing.