supplementary materials


gk2596 scheme

Acta Cryst. (2014). E70, o4    [ doi:10.1107/S1600536813032364 ]

2,6-Bis(bromo­meth­yl)pyridine

O. Cuzan, T. Straistari, C. Turta and M. Réglier

Abstract top

In the title mol­ecule, C7H7Br2N, the C-Br vectors of the bromo­methyl groups extend to opposite sides of the pyridine ring and are oriented nearly perpendicular to its plane. In the crystal, the mol­ecules related by a c-glide-plane operation are arranged into stacks along the c axis, with centroid-centroid distances between neighboring aromatic rings of 3.778 (2) Å. A short Br...Br contact of 3.6025 (11) Å is observed within a pair of inversion-related mol­ecules.

Comment top

2,6-Bis(bromomethyl)pyridine is a well known organic compound which serves as a precursor in various organic reactions leading to formation of a large range of pyridine derivatives. Additionally, the presence of N-donor atom enables coordination of metal ions by this molecule. Due to conformational flexibility of the bromomethyl arms, the title compound has been used as a starting material for the synthesis of macrocycles (Dioury et al., 2009).

Recently, the crystal structure of the Cl analogue of the title compound - 2,6-bis(chloromethyl)pyridine - has been reported and the two compounds form an isomorphous pair.

In the crystal, π-π stacking interaction between aromatic rings of molecules forming stacks along the c axis are observed. The distance between the centroids of the stacked pyridine rings is 3.778 (2) Å (symmetry code: x, 1/2 - y, -1/2 + z).

The bromine atoms are situated at both sides of the pyridine plane and bromomethyl arms are pointing at approximately opposite directions. In the crystal, there are two different Br···Br contacts of type I. The contact longer than the sum of van der Waals radii [Br2···Br1i 3.7051 (11) Å; symmetry code: (i) 1 + x, y, 1 + z] links the molecules into infinite chains along [1 0 1] whereas the other one [Br2···Br2iii 3.6025 (11) Å; symmetry code: (iii) -x, -y, -z] is formed between neighbouring chains.

Related literature top

For the isomorphous crystal structure of 2,6-bis(chloromethyl)pyridine, see: Betz et al. (2011). For the synthesis of 2,6-bis(bromomethyl)pyridine, see: Dioury et al. (2009).

Experimental top

The compund was obtained according to previously reported procedure from the 2,6-bis(hydroxymethyl)pyridine (Dioury et al., 2009). Crystals suitable for the X-ray diffraction study were obtained by recrystallization from diethylether at room temperature.

Refinement top

The H atoms were positioned geometrically and refined using a riding model with C—H = 0.95–0.99 Å and with Uiso(H) = 1.2 times Ueq(C).

Computing details top

Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2006) and XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: enCIFer (Allen et al., 2004) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as small spheres of arbitrary radius.
[Figure 2] Fig. 2. Intermolecular Br···Br contacts (dashed lines) in the title compound. Symmetry codes: (i) 1 + x, y, 1 + z; (ii) -1 + x, y, -1 + z; (iii) -x, -y, -z. H atoms have been omitted for clarity.
2,6-Bis(bromomethyl)pyridine top
Crystal data top
C7H7Br2NF(000) = 504
Mr = 264.96Dx = 2.072 Mg m3
Monoclinic, P21/cMelting point = 358–360 K
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 9.2955 (19) ÅCell parameters from 10219 reflections
b = 12.980 (3) Åθ = 2.8–30.4°
c = 7.5288 (15) ŵ = 9.47 mm1
β = 110.75 (3)°T = 293 K
V = 849.5 (3) Å3Platelet, colourless
Z = 40.28 × 0.26 × 0.12 mm
Data collection top
Nonius KappaCCD
diffractometer
2480 independent reflections
Radiation source: fine-focus sealed tube1923 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.048
ω and Phi scanθmax = 30.4°, θmin = 2.8°
Absorption correction: multi-scan
(SORTAV; Blessing, 1995)
h = 1113
Tmin = 0.088, Tmax = 0.321k = 1714
10219 measured reflectionsl = 108
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.044H-atom parameters constrained
wR(F2) = 0.119 w = 1/[σ2(Fo2) + (0.0467P)2 + 1.3504P]
where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max < 0.001
2480 reflectionsΔρmax = 0.99 e Å3
92 parametersΔρmin = 1.06 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.036 (3)
Crystal data top
C7H7Br2NV = 849.5 (3) Å3
Mr = 264.96Z = 4
Monoclinic, P21/cMo Kα radiation
a = 9.2955 (19) ŵ = 9.47 mm1
b = 12.980 (3) ÅT = 293 K
c = 7.5288 (15) Å0.28 × 0.26 × 0.12 mm
β = 110.75 (3)°
Data collection top
Nonius KappaCCD
diffractometer
2480 independent reflections
Absorption correction: multi-scan
(SORTAV; Blessing, 1995)
1923 reflections with I > 2σ(I)
Tmin = 0.088, Tmax = 0.321Rint = 0.048
10219 measured reflectionsθmax = 30.4°
Refinement top
R[F2 > 2σ(F2)] = 0.044H-atom parameters constrained
wR(F2) = 0.119Δρmax = 0.99 e Å3
S = 1.04Δρmin = 1.06 e Å3
2480 reflectionsAbsolute structure: ?
92 parametersAbsolute structure parameter: ?
0 restraintsRogers parameter: ?
Special details top

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
xyzUiso*/Ueq
Br10.97970 (5)0.13488 (4)0.59690 (7)0.0698 (2)
Br20.17000 (5)0.07677 (4)0.10894 (7)0.0696 (2)
N10.5656 (3)0.1307 (2)0.3525 (4)0.0461 (6)
C10.6810 (4)0.1899 (3)0.3462 (5)0.0447 (7)
C20.6751 (4)0.2963 (3)0.3423 (5)0.0509 (8)
H20.75800.33470.33710.061*
C30.5438 (5)0.3448 (3)0.3464 (6)0.0560 (9)
H30.53690.41620.34540.067*
C40.4230 (4)0.2844 (3)0.3521 (5)0.0535 (9)
H40.33290.31480.35360.064*
C50.4380 (4)0.1781 (3)0.3554 (5)0.0479 (8)
C60.8218 (4)0.1350 (4)0.3439 (6)0.0559 (9)
H6A0.86100.16880.25550.067*
H6B0.79570.06460.30150.067*
C70.3117 (5)0.1099 (4)0.3646 (6)0.0646 (11)
H7A0.25600.14410.43500.078*
H7B0.35520.04680.43100.078*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0465 (3)0.0867 (4)0.0672 (3)0.01422 (19)0.00885 (19)0.0045 (2)
Br20.0558 (3)0.0711 (3)0.0710 (3)0.01709 (19)0.0091 (2)0.0004 (2)
N10.0412 (15)0.0523 (16)0.0429 (15)0.0000 (12)0.0127 (12)0.0034 (12)
C10.0419 (16)0.0556 (19)0.0357 (15)0.0006 (14)0.0127 (13)0.0011 (13)
C20.0466 (18)0.056 (2)0.0481 (19)0.0040 (15)0.0141 (15)0.0016 (15)
C30.057 (2)0.052 (2)0.052 (2)0.0039 (16)0.0115 (17)0.0016 (16)
C40.0417 (17)0.070 (2)0.0460 (18)0.0105 (16)0.0117 (14)0.0023 (16)
C50.0382 (16)0.065 (2)0.0374 (16)0.0015 (14)0.0100 (13)0.0030 (15)
C60.0458 (19)0.072 (3)0.052 (2)0.0069 (17)0.0199 (16)0.0008 (17)
C70.048 (2)0.092 (3)0.055 (2)0.010 (2)0.0190 (18)0.008 (2)
Geometric parameters (Å, º) top
Br1—C61.950 (4)C3—H30.9300
Br2—C71.956 (4)C4—C51.387 (6)
N1—C11.334 (4)C4—H40.9300
N1—C51.343 (5)C5—C71.491 (5)
C1—C21.382 (6)C6—H6A0.9700
C1—C61.496 (5)C6—H6B0.9700
C2—C31.383 (6)C7—H7A0.9700
C2—H20.9300C7—H7B0.9700
C3—C41.382 (6)
C1—N1—C5117.5 (3)N1—C5—C7116.3 (4)
N1—C1—C2123.4 (3)C4—C5—C7121.1 (4)
N1—C1—C6116.3 (3)C1—C6—Br1110.4 (3)
C2—C1—C6120.3 (4)C1—C6—H6A109.6
C1—C2—C3118.8 (4)Br1—C6—H6A109.6
C1—C2—H2120.6C1—C6—H6B109.6
C3—C2—H2120.6Br1—C6—H6B109.6
C4—C3—C2118.4 (4)H6A—C6—H6B108.1
C4—C3—H3120.8C5—C7—Br2110.6 (3)
C2—C3—H3120.8C5—C7—H7A109.5
C3—C4—C5119.2 (3)Br2—C7—H7A109.5
C3—C4—H4120.4C5—C7—H7B109.5
C5—C4—H4120.4Br2—C7—H7B109.5
N1—C5—C4122.6 (3)H7A—C7—H7B108.1
C5—N1—C1—C20.0 (5)C1—N1—C5—C7179.4 (3)
C5—N1—C1—C6179.7 (3)C3—C4—C5—N10.3 (6)
N1—C1—C2—C30.4 (6)C3—C4—C5—C7179.0 (4)
C6—C1—C2—C3179.4 (3)N1—C1—C6—Br1100.1 (3)
C1—C2—C3—C40.7 (6)C2—C1—C6—Br179.7 (4)
C2—C3—C4—C50.6 (6)N1—C5—C7—Br291.3 (4)
C1—N1—C5—C40.0 (5)C4—C5—C7—Br289.4 (4)

Experimental details

Crystal data
Chemical formulaC7H7Br2N
Mr264.96
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)9.2955 (19), 12.980 (3), 7.5288 (15)
β (°) 110.75 (3)
V3)849.5 (3)
Z4
Radiation typeMo Kα
µ (mm1)9.47
Crystal size (mm)0.28 × 0.26 × 0.12
Data collection
DiffractometerNonius KappaCCD
diffractometer
Absorption correctionMulti-scan
(SORTAV; Blessing, 1995)
Tmin, Tmax0.088, 0.321
No. of measured, independent and
observed [I > 2σ(I)] reflections
10219, 2480, 1923
Rint0.048
(sin θ/λ)max1)0.713
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.119, 1.04
No. of reflections2480
No. of parameters92
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.99, 1.06

Computer programs: COLLECT (Nonius, 1998), DENZO/SCALEPACK (Otwinowski & Minor, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), Mercury (Macrae et al., 2006) and XP in SHELXTL (Sheldrick, 2008), enCIFer (Allen et al., 2004) and PLATON (Spek, 2009).

Acknowledgements top

We thank Dr Michel Giorgi (Spectropole, Aix Marseille University) for helpful advice. This research was supported by the bilateral Moldo–French project entitled `Nickel and iron complexes as models of active centre of hydrogenases' 13.820.08.01/FrF; nr. 170783.

references
References top

Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335–338.

Betz, R., Gerber, T. & Schalekamp, H. (2011). Acta Cryst. E67, o1577.

Blessing, R. H. (1995). Acta Cryst. A51, 33–38.

Dioury, F., Ferroud, C., Guy, A. & Port, M. (2009). Tetrahedron, 65, 7573–7579.

Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457.

Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands.

Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Spek, A. L. (2009). Acta Cryst. D65, 148–155.