p-Phenyl-enedimethanaminium dibromide.

In the title salt, C(8)H(14)N(2) (2+)·2Br(-), the cation has a crystallographically imposed centre of symmetry. The compound is isostructural with the chloride analogue. In the crystal structure, the cations and anions are connected via N-H⋯Br hydrogen bonds, forming layers parallel to the bc plane.

Related literature

For the synthesis, structures and properties of ferroelectric organic or inorganic compounds, see: Haertling (1999 ▶); Homes et al. (2001 ▶); Fu et al. (2009 ▶); Hang et al. (2009 ▶). For the structure of the isostructural chloride salt, see: Arkenbout et al. (2007 ▶).

Experimental

Crystal data

C8H14N2 2+·2Br−

M = 298.01

Triclinic,

a = 4.4462 (9) Å

b = 6.0331 (12) Å

c = 10.347 (2) Å

α = 101.90 (3)°

β = 99.79 (3)°

γ = 94.29 (3)°

V = 265.89 (9) Å3

Z = 1

Mo Kα radiation

μ = 7.58 mm−1

T = 293 K

0.20 × 0.20 × 0.20 mm

Data collection

Rigaku Mercury2 diffractometer

Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T min = 0.837, T max = 1.000

2767 measured reflections

1213 independent reflections

1107 reflections with I > 2σ(I)

R int = 0.053

Refinement

R[F 2 > 2σ(F 2)] = 0.034

wR(F 2) = 0.084

S = 1.10

1213 reflections

56 parameters

H-atom parameters constrained

Δρmax = 0.59 e Å−3

Δρmin = −0.68 e Å−3

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL/PC (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL/PC.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810024840/rz2469sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810024840/rz2469Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C8H14N22+·2Br−	Z = 1
Mr = 298.01	F(000) = 146
Triclinic, P1	Dx = 1.861 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.4462 (9) Å	Cell parameters from 1213 reflections
b = 6.0331 (12) Å	θ = 2.6–27.5°
c = 10.347 (2) Å	µ = 7.58 mm−1
α = 101.90 (3)°	T = 293 K
β = 99.79 (3)°	Prism, colorless
γ = 94.29 (3)°	0.20 × 0.20 × 0.20 mm
V = 265.89 (9) Å3

Rigaku Mercury2 diffractometer	1213 independent reflections
Radiation source: fine-focus sealed tube	1107 reflections with I > 2σ(I)
graphite	Rint = 0.053
Detector resolution: 13.6612 pixels mm-1	θmax = 27.5°, θmin = 3.5°
CCD_Profile_fitting scans	h = −5→5
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005)	k = −7→7
Tmin = 0.837, Tmax = 1.000	l = −13→13
2767 measured reflections

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.034	H-atom parameters constrained
wR(F2) = 0.084	w = 1/[σ2(Fo2) + (0.0314P)2] where P = (Fo2 + 2Fc2)/3
S = 1.10	(Δ/σ)max < 0.001
1213 reflections	Δρmax = 0.59 e Å−3
56 parameters	Δρmin = −0.68 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.102 (8)

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.

	x	y	z	Uiso*/Ueq
N1	0.5050 (7)	0.6880 (4)	0.8667 (3)	0.0352 (6)
H1A	0.4270	0.7394	0.9393	0.042*
H1B	0.6628	0.7845	0.8646	0.042*
H1C	0.5668	0.5525	0.8698	0.042*
C2	0.2679 (7)	0.6652 (6)	0.7437 (3)	0.0354 (8)
H2D	0.1943	0.8121	0.7417	0.042*
H2E	0.0952	0.5593	0.7466	0.042*
C5	0.3474 (8)	0.3493 (5)	0.5579 (3)	0.0345 (7)
H5A	0.2447	0.2476	0.5965	0.041*
C7	0.3911 (7)	0.5816 (5)	0.6174 (3)	0.0293 (7)
C10	0.4567 (8)	0.2702 (6)	0.4418 (3)	0.0353 (8)
H10A	0.4276	0.1150	0.4028	0.042*
Br1	−0.14338 (7)	0.20342 (5)	0.87105 (3)	0.03667 (19)

	U11	U22	U33	U12	U13	U23
N1	0.0523 (17)	0.0363 (15)	0.0199 (14)	0.0134 (12)	0.0156 (11)	0.0027 (12)
C2	0.0390 (17)	0.0412 (19)	0.0265 (17)	0.0107 (14)	0.0140 (13)	0.0005 (15)
C5	0.0451 (18)	0.0314 (17)	0.0300 (19)	0.0020 (13)	0.0145 (14)	0.0088 (15)
C7	0.0343 (16)	0.0345 (17)	0.0197 (16)	0.0071 (12)	0.0074 (12)	0.0040 (14)
C10	0.055 (2)	0.0265 (16)	0.0249 (18)	0.0067 (14)	0.0131 (15)	0.0013 (14)
Br1	0.0478 (3)	0.0329 (3)	0.0303 (3)	0.00763 (15)	0.01254 (16)	0.00384 (18)

N1—C2	1.483 (4)	C5—C10	1.380 (4)
N1—H1A	0.8880	C5—C7	1.394 (4)
N1—H1B	0.8839	C5—H5A	0.9300
N1—H1C	0.8865	C7—C10i	1.382 (5)
C2—C7	1.509 (4)	C10—C7i	1.382 (5)
C2—H2D	0.9700	C10—H10A	0.9300
C2—H2E	0.9700
C2—N1—H1A	109.9	H2D—C2—H2E	107.9
C2—N1—H1B	109.6	C10—C5—C7	120.0 (3)
H1A—N1—H1B	109.3	C10—C5—H5A	120.0
C2—N1—H1C	109.0	C7—C5—H5A	120.0
H1A—N1—H1C	109.4	C10i—C7—C5	119.1 (3)
H1B—N1—H1C	109.6	C10i—C7—C2	121.7 (3)
N1—C2—C7	111.9 (2)	C5—C7—C2	119.3 (3)
N1—C2—H2D	109.2	C5—C10—C7i	120.9 (3)
C7—C2—H2D	109.2	C5—C10—H10A	119.5
N1—C2—H2E	109.2	C7i—C10—H10A	119.5
C7—C2—H2E	109.2

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···Br1ii	0.89	2.49	3.359 (3)	167
N1—H1B···Br1iii	0.88	2.59	3.363 (3)	146
N1—H1C···Br1iv	0.89	2.55	3.422 (3)	167

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯Br1i	0.89	2.49	3.359 (3)	167
N1—H1B⋯Br1ii	0.88	2.59	3.363 (3)	146
N1—H1C⋯Br1iii	0.89	2.55	3.422 (3)	167

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