Hexane-1,6-diyldipyridinium dibromide

The cation of the title compound, C₁₆H₂₂N₂⁺·2Br^-, has a crystallographic inversion centre.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.035
• wR factor = 0.082
• Data-to-parameter ratio = 18.0

checkCIF/PLATON results

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Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)       3000 Deg.
PLAT180_ALERT_3_C Check Cell Rounding: # of Values Ending with 0 =          3
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.03
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C16 H22 N2

Alert level G
PLAT804_ALERT_5_G ARU-Pack Problem in PLATON Analysis ............          1 Times

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   5 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

The title compound, (I), with cucurbit[6,7,8]urils, can be utilized to form host–guest complexes (Cong et al., 2007), which are of wide current interest for application in molecular identification and molecular self-assembly. A relative crystal structure has already been reported (Ji et al., 2006). We report herein the crystal structure of the title compound, (I).

The asymmetric unit of the title compound, (I), contains one half molecule (Fig. 1), in which the bond lengths and angles (Table 1) are within normal ranges (Allen et al., 1987).

Related literature

For general background, see: Cong et al. (2007); Allen et al. (1987). For related literature, see: Ji et al. (2006).

S2. Experimental

For the preparation of the title compound, (I), 1,6-dibromohexane (12.2 g, 50 mmol) was added to 2-propanol solution (50 ml) of pyridine (9.5 g, 120 mmol) at 353 K. After stirring for 12 h, two layers were formed. The top layer containing the unreacted starting materials was decanted. The bottom layer, a white solid phase, was recrystallized by the addition of ethanol. Then, the crystals of (I) were obtained by evaporating the solvent slowly at room temperature for about 7 d.

S3. Refinement

H atoms were positioned geometrically, with C—H = 0.93 and 0.97 Å for aromatic and methylene H atoms, respectively, and constrained to ride on their parent atoms, with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: CAD-4 Software (Enraf–Nonius, 1985); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXTL.

Figures

Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level [symmetry code (A): 2 - x, -y, -z].

Hexane-1,6-diyldipyridinium dibromide

Crystal data

C16H22N2^2+·2Br^−	Z = 1
Mr = 402.16	F(000) = 202
Triclinic, P1	Dx = 1.596 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.4750 (15) Å	Cell parameters from 25 reflections
b = 7.9320 (16) Å	θ = 10–13°
c = 8.3450 (17) Å	µ = 4.84 mm^−1
α = 94.12 (3)°	T = 298 K
β = 115.64 (3)°	Block, colourless
γ = 105.91 (3)°	0.30 × 0.20 × 0.10 mm
V = 418.5 (2) Å^3

Data collection

Enraf–Nonius CAD-4 diffractometer	1155 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.054
Graphite monochromator	θmax = 26.0°, θmin = 2.7°
ω/2θ scans	h = −9→7
Absorption correction: ψ scan (North et al., 1968)	k = −9→9
Tmin = 0.326, Tmax = 0.617	l = 0→10
1774 measured reflections	3 standard reflections every 120 min
1639 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.082	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.04P)^2 + 0.3P] where P = (Fo^2 + 2Fc^2)/3
1639 reflections	(Δ/σ)max = 0.001
91 parameters	Δρmax = 0.65 e Å^−3
0 restraints	Δρmin = −0.43 e Å^−3

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 > 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.

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

	x	y	z	Uiso*/Ueq
Br	0.04735 (6)	0.78621 (5)	0.21069 (5)	0.04621 (16)
N	0.8561 (4)	1.2391 (4)	0.2347 (4)	0.0336 (6)
C1	0.5568 (6)	1.0791 (5)	0.2592 (5)	0.0491 (10)
H1A	0.4965	1.0004	0.3138	0.059*
C2	0.4352 (6)	1.1500 (5)	0.1262 (6)	0.0477 (10)
H2A	0.2912	1.1182	0.0875	0.057*
C3	0.5292 (6)	1.2688 (5)	0.0511 (6)	0.0506 (10)
H3A	0.4494	1.3204	−0.0374	0.061*
C4	0.7412 (6)	1.3119 (5)	0.1062 (5)	0.0427 (9)
H4A	0.8045	1.3915	0.0542	0.051*
C5	0.7674 (6)	1.1244 (5)	0.3114 (5)	0.0423 (9)
H5A	0.8498	1.0752	0.4009	0.051*
C6	1.0866 (5)	1.2841 (5)	0.2952 (5)	0.0400 (8)
H6A	1.1207	1.3419	0.2086	0.048*
H6B	1.1203	1.1743	0.2976	0.048*
C7	1.2187 (5)	1.4073 (5)	0.4823 (5)	0.0395 (8)
H7A	1.1776	1.3533	0.5673	0.047*
H7B	1.1927	1.5206	0.4779	0.047*
C8	1.4535 (5)	1.4423 (5)	0.5498 (5)	0.0383 (8)
H8A	1.5296	1.5000	0.6782	0.046*
H8B	1.4750	1.3278	0.5382	0.046*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br	0.0391 (2)	0.0478 (2)	0.0494 (2)	0.00794 (16)	0.02235 (17)	0.01417 (17)
N	0.0231 (14)	0.0321 (15)	0.0387 (16)	0.0015 (11)	0.0143 (12)	0.0007 (12)
C1	0.036 (2)	0.053 (2)	0.054 (2)	−0.0008 (18)	0.0275 (19)	0.006 (2)
C2	0.0256 (18)	0.049 (2)	0.059 (2)	0.0040 (17)	0.0202 (18)	−0.0100 (19)
C3	0.038 (2)	0.048 (2)	0.055 (2)	0.0176 (18)	0.0123 (18)	0.0030 (19)
C4	0.041 (2)	0.0343 (19)	0.050 (2)	0.0070 (16)	0.0219 (18)	0.0098 (17)
C5	0.0335 (19)	0.046 (2)	0.042 (2)	0.0064 (16)	0.0184 (16)	0.0095 (17)
C6	0.0251 (17)	0.043 (2)	0.048 (2)	0.0026 (15)	0.0204 (15)	−0.0018 (17)
C7	0.0226 (16)	0.042 (2)	0.048 (2)	0.0016 (15)	0.0189 (15)	0.0013 (17)
C8	0.0271 (17)	0.041 (2)	0.044 (2)	0.0064 (15)	0.0175 (15)	0.0052 (16)

Geometric parameters (Å, º)

N—C4	1.335 (5)	C5—H5A	0.9300
N—C5	1.341 (4)	C6—C7	1.512 (5)
N—C6	1.495 (4)	C6—H6A	0.9700
C1—C2	1.368 (6)	C6—H6B	0.9700
C1—C5	1.368 (5)	C7—C8	1.526 (4)
C1—H1A	0.9300	C7—H7A	0.9700
C2—C3	1.370 (6)	C7—H7B	0.9700
C2—H2A	0.9300	C8—C8^i	1.507 (7)
C3—C4	1.375 (5)	C8—H8A	0.9700
C3—H3A	0.9300	C8—H8B	0.9700
C4—H4A	0.9300
C4—N—C5	120.8 (3)	N—C6—C7	111.4 (3)
C4—N—C6	120.4 (3)	N—C6—H6A	109.3
C5—N—C6	118.8 (3)	C7—C6—H6A	109.3
C2—C1—C5	119.7 (4)	N—C6—H6B	109.3
C2—C1—H1A	120.1	C7—C6—H6B	109.3
C5—C1—H1A	120.1	H6A—C6—H6B	108.0
C1—C2—C3	118.8 (3)	C6—C7—C8	111.4 (3)
C1—C2—H2A	120.6	C6—C7—H7A	109.4
C3—C2—H2A	120.6	C8—C7—H7A	109.4
C2—C3—C4	120.2 (4)	C6—C7—H7B	109.4
C2—C3—H3A	119.9	C8—C7—H7B	109.4
C4—C3—H3A	119.9	H7A—C7—H7B	108.0
N—C4—C3	119.8 (4)	C8^i—C8—C7	114.5 (4)
N—C4—H4A	120.1	C8^i—C8—H8A	108.6
C3—C4—H4A	120.1	C7—C8—H8A	108.6
N—C5—C1	120.6 (4)	C8^i—C8—H8B	108.6
N—C5—H5A	119.7	C7—C8—H8B	108.6
C1—C5—H5A	119.7	H8A—C8—H8B	107.6
C5—C1—C2—C3	−1.5 (6)	C6—N—C5—C1	−179.7 (3)
C1—C2—C3—C4	1.5 (6)	C2—C1—C5—N	0.7 (6)
C5—N—C4—C3	−0.2 (5)	C4—N—C6—C7	106.6 (4)
C6—N—C4—C3	179.7 (3)	C5—N—C6—C7	−73.6 (4)
C2—C3—C4—N	−0.7 (6)	N—C6—C7—C8	175.9 (3)
C4—N—C5—C1	0.2 (5)	C6—C7—C8—C8^i	70.2 (5)

Symmetry code: (i) −x+3, −y+3, −z+1.