1,4-Bis­[2-(6-bromo­hexyl)-2H-tetrazol-5-yl]­benzene

Fleming, A.F.M.; Kelleher, F.; Mahon, M.F.; McGinley, J.; Molloy, K.C.; Prajapati, V.

doi:10.1107/S1600536804029770

organic compounds

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ISSN: 2056-9890

Volume 60| Part 12| December 2004| Pages o2388-o2389

https://doi.org/10.1107/S1600536804029770

1,4-Bis[2-(6-bromohexyl)-2H-tetrazol-5-yl]benzene

Adrienne F. M. Fleming,^a Fintan Kelleher,^a Mary F. Mahon,^b ^* John McGinley,^a Kieran C. Molloy ^b and Vipa Prajapati ^a

^aDepartment of Applied Science and Advanced Smart Materials Research Center, Institute of Technology, Tallaght, Dublin 24, Ireland, and ^bDepartment of Chemistry, University of Bath, Claverton Down, Bath BA1 7AY, England
^*Correspondence e-mail: m.f.mahon@bath.ac.uk

(Received 9 November 2004; accepted 16 November 2004; online 20 November 2004)

The 150 K structure of the title compound, C₂₀H₂₈Br₂N₈, has been shown to exhibit liquid-crystal alignment in the gross array, enhanced by the presence of intermolecular Br⋯Br interactions. The asymmetric unit consists of one-half of a molecule, the remainder being generated via a crystallographic inversion centre located at the centre of the benzene ring.

Comment

The synthesis of tetrazoles from the cycloaddition reaction between an azide and a nitrile is well established (Butler, 1996 ). Regioselective alkylation of tetrazoles has been the subject of several investigations during the last 20 years (Bethel et al., 1999 ; Goodger et al., 1996 ; Hill et al., 1996 ; Zubarev & Ostrovskii, 2000 ). Our group has recently studied the alkylation of 1,4-bis(1H-tetrazol-5-yl)benzene, (I), with various alkyl halides to give bifunctional products of type (II) with N-2 substitution in both tetrazole rings (Fleming et al., 2004 ). These compounds are intermediates in the generation of tetratetrazole macrocycles of general formula (III) which include a cavity of variable dimensions tailored by both the length and flexibility of the bridging groups X and Y (Butler & NíBhrádaigh, 1994 ; Butler et al., 1992 , 2001 ; Butler & Fleming, 1997 ). As part of our ongoing studies on this family of compounds, the structure of 1,4-bis[2-(6-bromohexyl)-2H-tetrazol-5-yl]benzene, (II), is now reported (Fig. 1).

The asymmetric unit consists of one half of a molecule, the remainder being generated via a crystallographic inversion centre located at the centre of the benzene ring. Both tetrazole rings are coplanar with the benzene ring to which they are attached (the largest deviation from the least-squares plane is 0.023 Å for atom C4). Analysis of the gross structure reveals slipped π stacking, with a distance of 3.38 Å between the least-squares planes of the tetrazole ring and the benzene ring of its closest neighbour (Fig. 2). It is also probable that liquid crystal alignment is present along the c axis in this structure, evidenced by an intermolecular distance of 3.4802 (4) Å between proximate terminal Br atoms (Fig. 3). This distance is considerably shorter than twice the bromine van der Waals radius (3.90 Å) and is within the range of those values previously reported, 3.415–3.691 Å (Christofi et al., 2000 ; Kuhn et al., 2004 ; Ruthe et al., 1997 ; Savinsky et al., 2001 ).

Figure 1
Plot of the title molecule. Displacement ellipsoids are drawn at the 30% probability level. Unlabelled atoms are related to labelled atoms by the symmetry operator (−x, −y, 1 − z).

Figure 2
Plot of two neighbouring molecules in the crystal structure of (II

), showing π stacking.

Figure 3
Partial packing diagram for (II

), illustrating intermolecular interactions and liquid-crystal alignment.

Experimental

A suspension of 1,4-bis(1H-tetrazol-5-yl)benzene (1.0 g, 4.7 mmol), methanol (30 ml) and triethylamine (1.90 g, 19 mmol) was stirred at 333 K for an hour. 1,6-Dibromohexane (3.6 g, 14 mmol) was then added and the mixture was heated under reflux for 5 h. The solvent was removed and the product was purified using column chromatography (hexane/ethyl acetate 80/20 initially followed by 60/40). Crystals suitable for X-ray diffraction were grown from acetonitrile.

Crystal data

C₂₀H₂₈Br₂N₈
M_r = 540.32
Triclinic, $[P\overline 1]$
a = 4.6290 (1) Å
b = 5.7030 (1) Å
c = 21.7111 (6) Å
α = 87.494 (1)°
β = 85.631 (1)°
γ = 78.312 (2)°
V = 559.40 (2) Å³
Z = 1
D_x = 1.604 Mg m⁻³
Mo Kα radiation
Cell parameters from 20 025reflections
θ = 12–18°
μ = 3.65 mm⁻¹
T = 150 (2) K
Irregular tablet, colourless
0.60 × 0.40 × 0.12 mm

Data collection

Nonius KappaCCD diffractometer
φ and ω scans
Absorption correction: multi-scan (Blessing, 1995 ) T_min = 0.187, T_max = 0.65
8752 measured reflections
3144 independent reflections
2680 reflections with I > 2σ(I)
R_int = 0.075
θ_max = 29.9°
h = −6 → 6
k = −7 → 7
l = −30 → 30

Refinement

Refinement on F²
R[F² > 2σ(F²)] = 0.048
wR(F²) = 0.131
S = 1.05
3144 reflections
136 parameters
H-atom parameters constrained
w = 1/[σ²(F_o²) + (0.0798P)² + 0.1247P] where P = (F_o² + 2F_c²)/3
(Δ/σ)_max = 0.001
Δρ_max = 1.11 e Å⁻³
Δρ_min = −1.18 e Å⁻³

H atoms were included at calculated positions and constrained to an ideal geometry, with C—H distances of 0.98 Å and with U_iso(H) = 1.2U_eq(C). The largest peak and deepest hole in the final difference map are located 849 and 0.769 Å, respectively, from atom Br1.

Data collection: COLLECT (Hooft, 1998 ); cell refinement: HKL DENZO (Otwinowski & Minor, 1997 ); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ); molecular graphics: ORTEX (McArdle, 1995 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, II. DOI: https://doi.org/10.1107/S1600536804029770/hg6111sup1.cif

Structure factors: contains datablock II. DOI: https://doi.org/10.1107/S1600536804029770/hg6111IIsup2.hkl

Computing details top

Data collection: COLLECT (Hooft, 1998); cell refinement: HKL DENZO (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEX (McArdle, 1995); software used to prepare material for publication: SHELXL97.

1,4-Bis[2-(6-bromohexyl)-2H-tetrazol-5-yl]benzene top

Crystal data top

C₂₀H₂₈Br₂N₈	Z = 1
M_r = 540.32	F(000) = 274
Triclinic, P1	D_x = 1.604 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 4.6290 (1) Å	Cell parameters from 25 reflections
b = 5.7030 (1) Å	θ = 12–18°
c = 21.7110 (6) Å	µ = 3.65 mm⁻¹
α = 87.494 (1)°	T = 150 K
β = 85.631 (1)°	Irregular tablet, colourless
γ = 78.312 (2)°	0.60 × 0.40 × 0.12 mm
V = 559.40 (2) Å³

Data collection top

Nonius KappaCCD diffractometer	3144 independent reflections
Radiation source: fine-focus sealed tube	2680 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.075
KappaCCD scans	θ_max = 29.9°, θ_min = 3.7°
Absorption correction: multi-scan (Blessing, 1995)	h = −6→6
T_min = 0.187, T_max = 0.65	k = −7→7
8752 measured reflections	l = −30→30

Refinement top

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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.131	H-atom parameters constrained
S = 1.05	w = 1/[σ²(F_o²) + (0.0798P)² + 0.1247P] where P = (F_o² + 2F_c²)/3
3144 reflections	(Δ/σ)_max = 0.001
136 parameters	Δρ_max = 1.11 e Å⁻³
0 restraints	Δρ_min = −1.18 e Å⁻³

Special details top

Experimental. 'multi-scan from symmetry-related measurements (Blessing, 1995)'

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 (Å²) top

	x	y	z	U_iso*/U_eq
Br1	1.40358 (6)	−1.26534 (5)	0.050985 (12)	0.03308 (13)
N1	0.7930 (5)	−0.0980 (4)	0.33633 (10)	0.0217 (4)
N2	0.6453 (5)	−0.1849 (4)	0.38397 (10)	0.0217 (4)
N3	0.6840 (6)	0.1309 (4)	0.32191 (11)	0.0292 (5)
N4	0.4560 (5)	0.1999 (4)	0.36189 (11)	0.0273 (5)
C1	0.4356 (6)	0.0064 (4)	0.39922 (11)	0.0207 (5)
C2	0.2114 (6)	0.0045 (4)	0.45048 (11)	0.0206 (5)
C3	0.0010 (6)	0.2117 (4)	0.46491 (12)	0.0233 (5)
H3	0.0004	0.3552	0.4409	0.028*
C4	−0.2067 (6)	0.2067 (4)	0.51438 (12)	0.0229 (5)
H4	−0.3472	0.3482	0.5245	0.027*
C5	1.0312 (6)	−0.2472 (5)	0.29910 (12)	0.0246 (5)
H5A	1.1472	−0.3700	0.3260	0.030*
H5B	1.1656	−0.1467	0.2794	0.030*
C6	0.9040 (6)	−0.3692 (5)	0.24945 (13)	0.0252 (5)
H6A	0.8035	−0.2459	0.2205	0.030*
H6B	0.7546	−0.4560	0.2691	0.030*
C7	1.1433 (6)	−0.5451 (5)	0.21343 (13)	0.0243 (5)
H7A	1.2859	−0.4564	0.1917	0.029*
H7B	1.2521	−0.6622	0.2427	0.029*
C8	1.0156 (6)	−0.6788 (5)	0.16645 (13)	0.0252 (5)
H8A	0.9235	−0.5629	0.1348	0.030*
H8B	0.8587	−0.7541	0.1876	0.030*
C9	1.2497 (6)	−0.8726 (5)	0.13441 (13)	0.0256 (5)
H9A	1.4096	−0.7988	0.1141	0.031*
H9B	1.3374	−0.9921	0.1657	0.031*
C10	1.1181 (7)	−0.9966 (5)	0.08686 (14)	0.0318 (6)
H10A	1.0477	−0.8797	0.0535	0.038*
H10B	0.9454	−1.0560	0.1064	0.038*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0440 (2)	0.02089 (17)	0.03148 (19)	0.00035 (12)	0.00067 (12)	−0.00647 (11)
N1	0.0283 (11)	0.0155 (9)	0.0208 (10)	−0.0037 (8)	−0.0010 (8)	0.0000 (7)
N2	0.0270 (11)	0.0158 (9)	0.0226 (10)	−0.0051 (8)	−0.0006 (8)	−0.0020 (7)
N3	0.0373 (13)	0.0183 (10)	0.0292 (12)	−0.0012 (9)	0.0015 (10)	0.0037 (9)
N4	0.0340 (13)	0.0184 (10)	0.0270 (11)	−0.0016 (9)	0.0014 (9)	0.0022 (8)
C1	0.0272 (12)	0.0150 (10)	0.0197 (11)	−0.0032 (9)	−0.0033 (9)	−0.0011 (8)
C2	0.0263 (12)	0.0137 (10)	0.0224 (11)	−0.0043 (8)	−0.0040 (9)	−0.0015 (8)
C3	0.0309 (13)	0.0133 (10)	0.0245 (12)	−0.0020 (9)	−0.0018 (10)	0.0005 (9)
C4	0.0283 (13)	0.0129 (10)	0.0251 (12)	0.0010 (9)	0.0001 (9)	−0.0014 (8)
C5	0.0261 (13)	0.0222 (12)	0.0245 (12)	−0.0028 (9)	0.0016 (9)	−0.0039 (9)
C6	0.0284 (13)	0.0193 (11)	0.0279 (13)	−0.0037 (9)	−0.0017 (10)	−0.0060 (9)
C7	0.0250 (13)	0.0196 (11)	0.0276 (13)	−0.0020 (9)	−0.0025 (10)	−0.0030 (9)
C8	0.0290 (13)	0.0194 (11)	0.0267 (13)	−0.0023 (9)	−0.0032 (10)	−0.0046 (9)
C9	0.0263 (13)	0.0197 (11)	0.0297 (14)	−0.0011 (9)	−0.0028 (10)	−0.0028 (10)
C10	0.0304 (14)	0.0283 (14)	0.0334 (15)	0.0048 (11)	−0.0036 (11)	−0.0113 (11)

Geometric parameters (Å, º) top

Br1—C10	1.957 (3)	C5—H5B	0.9900
N1—N2	1.330 (3)	C6—C7	1.527 (4)
N1—N3	1.333 (3)	C6—H6A	0.9900
N1—C5	1.462 (3)	C6—H6B	0.9900
N2—C1	1.340 (3)	C7—C8	1.521 (4)
N3—N4	1.321 (3)	C7—H7A	0.9900
N4—C1	1.355 (3)	C7—H7B	0.9900
C1—C2	1.464 (4)	C8—C9	1.532 (4)
C2—C4ⁱ	1.400 (3)	C8—H8A	0.9900
C2—C3	1.401 (3)	C8—H8B	0.9900
C3—C4	1.389 (4)	C9—C10	1.507 (4)
C3—H3	0.9500	C9—H9A	0.9900
C4—C2ⁱ	1.400 (3)	C9—H9B	0.9900
C4—H4	0.9500	C10—H10A	0.9900
C5—C6	1.524 (4)	C10—H10B	0.9900
C5—H5A	0.9900

N2—N1—N3	113.8 (2)	C5—C6—H6B	109.2
N2—N1—C5	122.8 (2)	C7—C6—H6B	109.2
N3—N1—C5	123.1 (2)	H6A—C6—H6B	107.9
N1—N2—C1	101.6 (2)	C8—C7—C6	112.2 (2)
N4—N3—N1	106.2 (2)	C8—C7—H7A	109.2
N3—N4—C1	106.1 (2)	C6—C7—H7A	109.2
N2—C1—N4	112.3 (2)	C8—C7—H7B	109.2
N2—C1—C2	123.4 (2)	C6—C7—H7B	109.2
N4—C1—C2	124.3 (2)	H7A—C7—H7B	107.9
C4ⁱ—C2—C3	119.5 (2)	C7—C8—C9	112.6 (2)
C4ⁱ—C2—C1	119.7 (2)	C7—C8—H8A	109.1
C3—C2—C1	120.8 (2)	C9—C8—H8A	109.1
C4—C3—C2	119.8 (2)	C7—C8—H8B	109.1
C4—C3—H3	120.1	C9—C8—H8B	109.1
C2—C3—H3	120.1	H8A—C8—H8B	107.8
C3—C4—C2ⁱ	120.7 (2)	C10—C9—C8	111.3 (2)
C3—C4—H4	119.6	C10—C9—H9A	109.4
C2ⁱ—C4—H4	119.6	C8—C9—H9A	109.4
N1—C5—C6	110.2 (2)	C10—C9—H9B	109.4
N1—C5—H5A	109.6	C8—C9—H9B	109.4
C6—C5—H5A	109.6	H9A—C9—H9B	108.0
N1—C5—H5B	109.6	C9—C10—Br1	112.1 (2)
C6—C5—H5B	109.6	C9—C10—H10A	109.2
H5A—C5—H5B	108.1	Br1—C10—H10A	109.2
C5—C6—C7	111.9 (2)	C9—C10—H10B	109.2
C5—C6—H6A	109.2	Br1—C10—H10B	109.2
C7—C6—H6A	109.2	H10A—C10—H10B	107.9

Symmetry code: (i) −x, −y, −z+1.

References

Bethel, P. A., Hill, M. S., Mahon, M. F. & Molloy, K. C. (1999). J. Chem. Soc. Perkin Trans. 1, pp. 3507–3514. Web of Science CSD CrossRef Google Scholar
Blessing, R. H. (1995). Acta Cryst. A51, 33–37. CrossRef CAS Web of Science IUCr Journals Google Scholar
Butler, R. N. (1996). Comprehensive Heterocyclic Chemistry, Vol. 4, edited by A. R. Katrilzky, C. W. Rees & E. F. V. Scriven. Oxford: Pergamon. Google Scholar
Butler, R. N. & Fleming, A. F. M. (1997). J. Heterocycl. Chem. 34, 691–693. CrossRef CAS Google Scholar
Butler, R. N., McGinley, J., Mahon, M. F., Molloy, K. C. & NíBhrádaigh, E. P. (2001) Acta Cryst. E57, o195–o197. Web of Science CSD CrossRef IUCr Journals Google Scholar
Butler, R. N. & NíBhrádaigh, E. P. (1994). J. Chem. Res. (S), pp. 148–149. Google Scholar
Butler, R. N., Quinn, K. F. & Welke, B. (1992). J. Chem. Soc. Chem. Commun. pp. 1481–1482. CrossRef Web of Science Google Scholar
Christofi, A. M., Garratt, P. J., Hogarth, G. & Steed, J. W. (2000). J. Chem. Soc. Dalton Trans. pp. 2137–2144. Web of Science CSD CrossRef Google Scholar
Fleming, A. F. M., Kelleher, F., Mahon, M. F., McGinley, J. & Prajapati, V. (2004). Unpublished work. Google Scholar
Goodger, A., Hill, M. S., Mahon, M. F., McGinley, J. & Molloy, K. C. (1996). J. Chem. Soc. Dalton Trans. pp. 847–852. CSD CrossRef Web of Science Google Scholar
Hill, M. S., Mahon, M. F., McGinley, J. & Molloy, K. C. (1996). J. Chem. Soc. Dalton Trans. pp. 835–845. CSD CrossRef Web of Science Google Scholar
Hooft, R. (1998). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Kuhn, N., Abu-Rayyan, A., Eichele, K., Schwarz, S. & Steimann, M. (2004). Inorg. Chim. Acta, 357, 1799–1804. Web of Science CSD CrossRef CAS Google Scholar
McArdle, P. (1995). J. Appl. Cryst. 28, 65. CrossRef IUCr Journals Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr and R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Ruthe, F., Du Mont, W.-W. & Jones, P. G. (1997). Chem. Commun. p. 1947. CrossRef Google Scholar
Savinsky, R., Hopf, H., Dix, I. & Jones, P. G. (2001). Eur. J. Org. Chem. pp. 4595–4606. CrossRef Google Scholar
Sheldrick, G. M. (1990). Acta Cryst. A46, 467–473. CrossRef CAS Web of Science IUCr Journals Google Scholar
Sheldrick, G. M. (1997). SHELXL97. University of Göttingen, Germany. Google Scholar
Zubarev, V. Y. & Ostrovskii, V. A. (2000). Chem. Heterocycl. Compds, 53, 1421–1448. Google Scholar

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