4-Cyano­anilinium bromide

Abstract

In the crystal structure of the title compound, C₇H₇N₂ ⁺·Br⁻, the cations are associated into inversion dimers through weak pairwise C—H⋯N hydrogen bonds. The dimers further form stepped sheets via weak pairwise C—H⋯N hydrogen bonds. In the sheets, the spacing between the mean planes of the laterally displaced aromatic rings in adjacent dimers is 1.124 (6) Å. Three N—H⋯Br inter­actions and two weak C—H⋯Br inter­actions per cation tie the sheets together.

Related literature  

For the structure of 4-cyano­anilinium choride, see: Colapietro et al. (1981 ▶). For the structure of 4-cyano­anilinium iodide, see: Mague et al. (2012 ▶). For the structure of anilinium bromide, see: Schweiss et al. (1983 ▶). For a discussion of C—H and N—H hydrogen bonding to halide ions, see: Steiner (1998 ▶).

Experimental  

Crystal data  

• C₇H₇N₂ ⁺·Br⁻

• M _r = 199.06

• Triclinic,

• a = 4.3102 (10) Å

• b = 6.1076 (13) Å

• c = 14.510 (3) Å

• α = 91.719 (3)°

• β = 93.290 (3)°

• γ = 101.428 (3)°

• V = 373.46 (14) ų

• Z = 2

• Mo Kα radiation

• μ = 5.42 mm⁻¹

• T = 100 K

• 0.20 × 0.19 × 0.16 mm

Data collection  

• Bruker SMART APEX CCD diffractometer

• Absorption correction: numerical (SADABS; Sheldrick, 2009 ▶) T _min = 0.631, T _max = 0.837

• 6534 measured reflections

• 1874 independent reflections

• 1802 reflections with I > 2σ(I)

• R _int = 0.032

Refinement  

• R[F ² > 2σ(F ²)] = 0.020

• wR(F ²) = 0.051

• S = 1.06

• 1874 reflections

• 91 parameters

• H-atom parameters constrained

• Δρ_max = 0.86 e Å⁻³

• Δρ_min = −0.41 e Å⁻³

Data collection: APEX2 (Bruker, 2010 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXM (Sheldrick, 1998 ▶, 2004 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536812037014/jj2147Isup3.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
N1—H1A⋯Br1	0.88	2.47	3.3209 (16)	162
C2—H2⋯Br1i	0.95	2.87	3.7316 (18)	151
C3—H3⋯N2ii	0.95	2.62	3.466 (2)	149
C5—H5⋯N2iii	0.95	2.69	3.517 (2)	146
C6—H6⋯Br1iv	0.95	3.00	3.8063 (18)	144
N1—H1B⋯Br1iv	0.88	2.54	3.4174 (16)	175
N1—H1C⋯Br1v	0.88	2.49	3.3400 (16)	162

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) .

supplementary crystallographic information

Comment

In the title compound, [C₇H₇N₂]⁺ Br^-, the cations are associated into dimers through weak, pairwise C3—H3···N2 intermolecular interactions (Fig. 1). The dimers further form stepped sheets via weak, pairwise C5—H5···N2 intermolecular interactions. In these sheets the spacing between the mean planes of the aromatic rings in adjacent dimers is 1.124 (6) Å (Table 1). The three hydrogen atoms of the anilinium group make contacts with the surrounding anions of 2.47 - 2.54 Å. These distances compare well with the mean value of 2.49 (2) Å for an N⁺—H···Br^- hydrogen bond (Steiner, 1998) and serve, together with weak C2—H2···Br1 and C6—H6···Br1 interactions, to tie the stepped sheets into a layer structure (Fig. 2) with the layers 3.493 (7) Å apart and forming rectangular channels of width ca 12.8 Å (Fig. 3).

Experimental

0.55 g of 4-cyanoaniline and 2.5 ml of aquous hydrobromic acid (2 M) were combined in 10 ml of ethanol. This solution was slowly evaporated to dryness under ambient conditions to form crystals of the title compound.

Refinement

H-atoms attached to C were placed in calculated positions (C—H = 0.95 - 0.98 Å) while those attached to N were placed in sites determined from a difference map and their coordinates adjusted to give N—H = 0.88 Å. All H-atoms were included as riding contributions with isotropic displacement parameters 1.2 times those of the attached atoms.

Figures

Fig. 1.

Perspective view of the asymmetric unit with displacement ellipsoids drawn at the 50% probability level

Fig. 2.

Packing showing the stepped layer structure. N—H···Br, C—H···N and C—H···Br interactions are shown as dashed lines. Color key: C = gray, H = orange, Br = red, N = blue.

Fig. 3.

Packing showing the rectangular channels. N—H···Br, C—H···N and C—H···Br interactions are shown as dashed lines. Color key: C = gray, H = orange, Br = red, N = blue.

Crystal data

C7H7N2+·Br−	Z = 2
Mr = 199.06	F(000) = 196
Triclinic, P1	Dx = 1.770 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.3102 (10) Å	Cell parameters from 5589 reflections
b = 6.1076 (13) Å	θ = 2.8–29.1°
c = 14.510 (3) Å	µ = 5.42 mm−1
α = 91.719 (3)°	T = 100 K
β = 93.290 (3)°	Block, colourless
γ = 101.428 (3)°	0.20 × 0.19 × 0.16 mm
V = 373.46 (14) Å3

Data collection

Bruker SMART APEX CCD diffractometer	1874 independent reflections
Radiation source: fine-focus sealed tube	1802 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
φ and ω scans	θmax = 29.2°, θmin = 2.8°
Absorption correction: numerical (SADABS; Sheldrick, 2009)	h = −5→5
Tmin = 0.631, Tmax = 0.837	k = −8→8
6534 measured reflections	l = −19→19

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.020	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.051	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0248P)2 + 0.1891P] where P = (Fo2 + 2Fc2)/3
1874 reflections	(Δ/σ)max = 0.002
91 parameters	Δρmax = 0.86 e Å−3
0 restraints	Δρmin = −0.41 e Å−3

Special details

Experimental. The diffraction data were obtained from 3 sets of 400 frames, each of width 0.5 °. in omega, collected at phi = 0.00, 90.00 and 180.00 °. and 2 sets of 800 frames, each of width 0.45 ° in phi, collected at omega = -30.00 and 210.00 °. The scan time was 10 sec/frame.

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 > σ(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. H-atoms attached to carbon were placed in calculated positions (C—H = 0.95 Å) while those attached to nitrogen were placed in locations derived from a difference map and then their coordinates adjusted to give an N—H distance of 0.88 Å. All were included as riding contributions with isotropic displacement parameters 1.2 times those of the attached atoms.

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

	x	y	z	Uiso*/Ueq
Br1	0.08172 (3)	0.73901 (2)	0.423553 (10)	0.01208 (7)
N1	0.5934 (3)	0.7244 (2)	0.60221 (10)	0.0128 (3)
H1A	0.4298	0.7029	0.5615	0.015*
H1B	0.6868	0.6102	0.5940	0.015*
H1C	0.7187	0.8527	0.5922	0.015*
N2	0.1311 (4)	0.7765 (3)	1.04130 (11)	0.0215 (3)
C1	0.4868 (4)	0.7327 (3)	0.69615 (11)	0.0117 (3)
C2	0.3482 (4)	0.9098 (3)	0.72253 (12)	0.0142 (3)
H2	0.3199	1.0208	0.6801	0.017*
C3	0.2514 (4)	0.9219 (3)	0.81193 (12)	0.0148 (3)
H3	0.1545	1.0409	0.8312	0.018*
C4	0.2980 (4)	0.7575 (3)	0.87320 (12)	0.0140 (3)
C5	0.4367 (4)	0.5796 (3)	0.84545 (12)	0.0158 (3)
H5	0.4650	0.4679	0.8875	0.019*
C6	0.5326 (4)	0.5674 (3)	0.75594 (12)	0.0142 (3)
H6	0.6278	0.4481	0.7361	0.017*
C7	0.2031 (4)	0.7694 (3)	0.96694 (13)	0.0168 (3)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Br1	0.01341 (9)	0.01043 (10)	0.01308 (10)	0.00377 (6)	0.00081 (6)	0.00256 (6)
N1	0.0141 (6)	0.0118 (7)	0.0130 (7)	0.0032 (5)	0.0006 (5)	0.0018 (5)
N2	0.0304 (9)	0.0179 (8)	0.0179 (8)	0.0073 (7)	0.0055 (7)	0.0020 (6)
C1	0.0118 (7)	0.0123 (8)	0.0102 (7)	0.0013 (6)	−0.0010 (6)	−0.0002 (6)
C2	0.0159 (8)	0.0124 (8)	0.0149 (8)	0.0040 (6)	0.0000 (6)	0.0033 (6)
C3	0.0167 (8)	0.0127 (8)	0.0157 (8)	0.0050 (7)	0.0009 (6)	0.0001 (6)
C4	0.0141 (8)	0.0150 (8)	0.0122 (8)	0.0017 (6)	0.0007 (6)	0.0008 (6)
C5	0.0185 (8)	0.0143 (8)	0.0152 (8)	0.0047 (7)	0.0007 (6)	0.0038 (6)
C6	0.0165 (8)	0.0118 (8)	0.0152 (8)	0.0045 (6)	0.0008 (6)	0.0018 (6)
C7	0.0201 (8)	0.0125 (8)	0.0181 (9)	0.0038 (7)	0.0011 (7)	0.0026 (6)

Geometric parameters (Å, º)

N1—C1	1.466 (2)	C2—H2	0.9500
N1—H1A	0.8800	C3—C4	1.397 (2)
N1—H1B	0.8801	C3—H3	0.9500
N1—H1C	0.8800	C4—C5	1.399 (2)
N2—C7	1.142 (3)	C4—C7	1.447 (2)
C1—C6	1.387 (2)	C5—C6	1.390 (2)
C1—C2	1.389 (2)	C5—H5	0.9500
C2—C3	1.390 (2)	C6—H6	0.9500
C1—N1—H1A	110.3	C2—C3—H3	120.3
C1—N1—H1B	110.7	C4—C3—H3	120.3
H1A—N1—H1B	106.0	C3—C4—C5	120.97 (16)
C1—N1—H1C	108.9	C3—C4—C7	120.11 (16)
H1A—N1—H1C	108.7	C5—C4—C7	118.91 (16)
H1B—N1—H1C	112.2	C6—C5—C4	119.56 (16)
C6—C1—C2	122.32 (16)	C6—C5—H5	120.2
C6—C1—N1	119.28 (15)	C4—C5—H5	120.2
C2—C1—N1	118.38 (15)	C1—C6—C5	118.79 (16)
C1—C2—C3	118.97 (16)	C1—C6—H6	120.6
C1—C2—H2	120.5	C5—C6—H6	120.6
C3—C2—H2	120.5	N2—C7—C4	178.9 (2)
C2—C3—C4	119.38 (16)
C6—C1—C2—C3	−0.1 (3)	C7—C4—C5—C6	−179.23 (17)
N1—C1—C2—C3	−178.82 (15)	C2—C1—C6—C5	−0.1 (3)
C1—C2—C3—C4	0.5 (3)	N1—C1—C6—C5	178.66 (15)
C2—C3—C4—C5	−0.8 (3)	C4—C5—C6—C1	−0.2 (3)
C2—C3—C4—C7	179.08 (16)	C3—C4—C7—N2	−162 (11)
C3—C4—C5—C6	0.7 (3)	C5—C4—C7—N2	18 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···Br1	0.88	2.47	3.3209 (16)	162
C2—H2···Br1i	0.95	2.87	3.7316 (18)	151
C3—H3···N2ii	0.95	2.62	3.466 (2)	149
C5—H5···N2iii	0.95	2.69	3.517 (2)	146
C6—H6···Br1iv	0.95	3.00	3.8063 (18)	144
N1—H1B···Br1iv	0.88	2.54	3.4174 (16)	175
N1—H1C···Br1v	0.88	2.49	3.3400 (16)	162

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