3-Hydroxy­anilinium bromide

The asymmetric unit of the title compound, C₆H₈NO⁺·Br⁻, consists of a 3-hydroxy­anilinium cation and a bromide anion. The ions are connected into a three-dimensional hydrogen-bonded network via O—H...Br, N—H...Br and N—H...O hydrogen bonds, with four characteristic graph-set motifs: C₂¹(8), C₃²(6), R₄²(8) and R₆⁴(12).

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C)= 0.004 Å
• R factor = 0.030
• wR factor = 0.082
• Data-to-parameter ratio = 18.8

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S1. Comment

This work is part of our research on intermolecular interactions in hydrogen-bonded ionic crystals, acid salts. The title compound (I), C₆H₈NO⁺ Br^-, was originally prepared as part of salt screening of the hydroxy- and carboxyanilines.

The molecular structure of (I) is shown in Fig. 1. The asymmetric unit consists of 3-hydroxyanilinium cation with protonated amino-group and bromine anion. All bond lengths and bond angles correspond to the geometry parameters expected for atom types and the type of hybridization (Allen et al., 1987). The ions are connected in three-dimensional hydrogen-bonded network via O–H···Br, N–H···Br, and N–H···O hydrogen bonds. All ammonium group H atoms are involved in the hydrogen bonding with two Br atoms and O-atom of hydroxyl group of neighbouring cation, with three-centred geometry motif observed. Four characteristic graph-set motifs can be recognized: C₂¹(8), C₃²(6), R₄²(8) and R₆⁴(12) in the notation of Bernstein et al., (1995). Two infinite one-dimensional chains are detected with the donor participations of H31A in C₂¹(8) motif and H31B and H31C in C₃²(6) graph-set motif. An eight-membered ring moiety [R₄²(8)] is formed of two hydroxyanilinium cations and two bridging bromine anions through the N31–H31A···Br1···H31B–N31 hydrogen bonds. The centre of 8-membered ring is situated on a crystallographic centre of symmetry. A twelve-membered ring moiety [R₆⁴(12)] is formed of four hydroxyanilinium cations and two bridging bromine anions by means of O1–H1···Br1···H31A–N31–H31C···O1 hydrogen bonding. The aggregation of two ring moieties results in infinite one-dimensional chains spreading along the c axis, with intercalated array of bromine ions, Fig. 2. The bromine anions act as acceptor atoms for two different H atoms, one of the ammonium group, and one of the hydroxyl group. Fig. 3 neatly shows two-dimensional packing of ions in ac plane where layers of 3-hydroxyanilinium cations are embedded between ionic layers of bromide anions, forming of alternating hydrocarbon-ionic structure.

Related literature

For related literature, see: Lemmerer & Billing (2006); Bernstein et al. (1995). For bond length data, see: Allen et al. (1987).

S2. Experimental

Single crystals of (I) were obtained by slow evaporation method. A solution of 100 mg 3-aminophenol dissolved in 2 ml of 1-butanol was heated at 343 K. The clear solution was obtained, added to the 1 ml of hydrobromic acid (2 M) and then left at room temperature. The crystals of (I) were collected by vacuum filtration, washed out with cold acetone and dried in air.

S3. Refinement

All N– and O-bound H atoms were located in difference Fourier map. The positions and isotropic parameters of N-bound H atoms were refined, but O-bound H atom was treated as riding atom. Aromatic H atoms were placed in calculated positions and treated as riding on their parent C atoms, with C–H = 0.93 Å and U_iso(H) = 1.2U_eq(C) for Csp².

Computing details

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, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999), PARST97 (Nardelli, 1995) and Mercury (Version 1.4; Macrae et al., 2006).

Figures

	Fig. 1. The asymetric unit of (I), showing the crystallographic numbering scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radius.
	Fig. 2. A view of the one-dimensional H-bonded chain along a axis showing the aggregation of two different H-bonding motifs, R4^2(8) and R6^4(12). Hydrogen bonds are drawn as red dotted lines.
	Fig. 3. Packing diagram of (I) viewed along b axis. The 3-hydroxyanilinium cations are shown in red colour and bromide anions are shown as blue spheres.

3-Hydroxyanilinium bromide

Crystal data

C6H8NO^+·Br^−	Z = 4
Mr = 190.03	F(000) = 376
Monoclinic, P21/n	Dx = 1.707 Mg m^−3
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 7.6661 (14) Å	µ = 5.48 mm^−1
b = 6.1482 (9) Å	T = 295 K
c = 15.792 (2) Å	Prism, colourles
β = 96.437 (13)°	0.45 × 0.11 × 0.11 mm
V = 739.6 (2) Å^3

Data collection

Oxford Diffraction Xcalibur CCD diffractometer	1786 independent reflections
Radiation source: fine-focus sealed tube	1554 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.037
ω scans	θmax = 28.1°, θmin = 4.2°
Absorption correction: analytical (Alcock, 1970)	h = −10→10
Tmin = 0.182, Tmax = 0.605	k = −8→8
7503 measured reflections	l = −20→20

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.030	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.082	w = 1/[σ^2(Fo^2) + (0.0427P)^2 + 0.1564P] where P = (Fo^2 + 2Fc^2)/3
S = 0.95	(Δ/σ)max = 0.004
1786 reflections	Δρmax = 0.53 e Å^−3
95 parameters	Δρmin = −0.56 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.017 (2)

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br1	0.80396 (3)	0.27270 (4)	1.015679 (15)	0.04682 (14)
O1	0.4811 (2)	0.3603 (3)	0.87080 (11)	0.0526 (5)
H1	0.5343	0.3778	0.9183	0.079*
N31	0.3571 (4)	0.7140 (4)	0.59956 (15)	0.0446 (5)
C1	0.5036 (3)	0.5387 (4)	0.82171 (15)	0.0398 (5)
C2	0.4210 (3)	0.5363 (4)	0.73883 (14)	0.0383 (5)
H2	0.3531	0.4181	0.7184	0.046*
C3	0.4423 (3)	0.7140 (4)	0.68767 (15)	0.0366 (5)
C4	0.5425 (3)	0.8913 (4)	0.71549 (16)	0.0457 (6)
H4	0.5557	1.0086	0.6796	0.055*
C5	0.6225 (3)	0.8901 (4)	0.79794 (17)	0.0505 (6)
H5	0.6907	1.0084	0.8179	0.061*
C6	0.6033 (4)	0.7159 (4)	0.85170 (19)	0.0473 (6)
H6	0.6571	0.7180	0.9075	0.057*
H31A	0.331 (4)	0.581 (6)	0.5828 (18)	0.058 (8)*
H31B	0.424 (5)	0.766 (5)	0.567 (3)	0.071 (12)*
H31C	0.260 (6)	0.787 (6)	0.599 (2)	0.073 (12)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0570 (2)	0.04004 (18)	0.04346 (18)	0.00182 (10)	0.00558 (11)	0.00423 (9)
O1	0.0576 (11)	0.0510 (11)	0.0477 (10)	−0.0046 (9)	−0.0012 (8)	0.0104 (8)
N31	0.0545 (13)	0.0391 (12)	0.0397 (11)	0.0020 (11)	0.0031 (10)	−0.0012 (9)
C1	0.0372 (11)	0.0413 (13)	0.0419 (12)	0.0029 (9)	0.0084 (9)	0.0001 (10)
C2	0.0359 (11)	0.0339 (12)	0.0451 (12)	−0.0015 (9)	0.0050 (9)	−0.0044 (9)
C3	0.0349 (10)	0.0369 (12)	0.0385 (12)	0.0046 (9)	0.0064 (9)	−0.0043 (9)
C4	0.0486 (13)	0.0364 (13)	0.0530 (14)	−0.0040 (10)	0.0100 (11)	−0.0029 (11)
C5	0.0496 (14)	0.0406 (14)	0.0610 (16)	−0.0088 (11)	0.0053 (12)	−0.0091 (12)
C6	0.0446 (13)	0.0519 (15)	0.0443 (14)	−0.0017 (11)	−0.0003 (10)	−0.0084 (11)

Geometric parameters (Å, º)

O1—C1	1.365 (3)	C2—C3	1.379 (3)
O1—H1	0.8200	C2—H2	0.9300
N31—C3	1.470 (3)	C3—C4	1.377 (3)
N31—H31A	0.88 (3)	C4—C5	1.376 (4)
N31—H31B	0.83 (4)	C4—H4	0.9300
N31—H31C	0.87 (4)	C5—C6	1.385 (4)
C1—C6	1.384 (3)	C5—H5	0.9300
C1—C2	1.389 (3)	C6—H6	0.9300
C1—O1—H1	109.5	C4—C3—C2	122.6 (2)
C3—N31—H31A	110.4 (18)	C4—C3—N31	118.4 (2)
C3—N31—H31B	110 (3)	C2—C3—N31	119.0 (2)
H31A—N31—H31B	108 (3)	C5—C4—C3	118.1 (2)
C3—N31—H31C	107 (2)	C5—C4—H4	120.9
H31A—N31—H31C	109 (3)	C3—C4—H4	120.9
H31B—N31—H31C	113 (3)	C4—C5—C6	121.2 (2)
O1—C1—C6	122.6 (2)	C4—C5—H5	119.4
O1—C1—C2	117.0 (2)	C6—C5—H5	119.4
C6—C1—C2	120.5 (2)	C1—C6—C5	119.5 (2)
C3—C2—C1	118.2 (2)	C1—C6—H6	120.3
C3—C2—H2	120.9	C5—C6—H6	120.3
C1—C2—H2	120.9

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···Br1	0.82	2.52	3.222 (2)	145
N31—H31A···Br1^i	0.88 (4)	2.42 (4)	3.279 (3)	168 (3)
N31—H31B···Br1^ii	0.84 (4)	2.57 (5)	3.355 (3)	156 (4)
N31—H31C···O1^iii	0.87 (4)	2.01 (5)	2.833 (4)	158 (4)

Symmetry codes: (i) x−1/2, −y+1/2, z−1/2; (ii) −x+3/2, y+1/2, −z+3/2; (iii) −x+1/2, y+1/2, −z+3/2.