Crystal structure of 3-bromo-pyridine N-oxide.

In the title compound, C5H4BrNO, there are two mol-ecules in the asymmetric unit that are related by a pseudo-inversion center. The two independent mol-ecules are approximately planar, with an observed (ring-ring) angle of 5.49 (13)°. The crystal structure exhibits a herringbone pattern with the zigzag running along the b-axis direction. The least-squares plane containing the rings of both asymmetric molecules and the plane containing the symmetrically related mol-ecules make a plane-plane angle of 66.69 (10)°, which makes the bend of the herringbone pattern. The bromo group on one mol-ecule points to the bromo group on the neighboring mol-ecule, with a Br⋯Br inter-molecular distance of 4.0408 (16) Å. The herringbone layer-to-layer distance is 3.431 (4) Å with a shift of 1.742 (7) Å. There are no short contacts, hydrogen bonds, or π-π inter-actions.

Related literature

For the synthesis of pyridine N-oxide-related compounds, see: Rousseau & Robins (1965 ▸). For an example of the chemistry of the title compound and its use in catalysed cyclization of alkynyl oxiranes and oxetanes, see: Gronnier et al. (2012 ▸).

Experimental

Crystal data

C5H4BrNO

M = 174.00

Monoclinic,

a = 7.832 (5) Å

b = 18.398 (10) Å

c = 8.298 (5) Å

β = 92.906 (5)°

V = 1194.2 (12) Å3

Z = 8

Mo Kα radiation

μ = 6.77 mm−1

T = 173 K

0.3 × 0.3 × 0.2 mm

Data collection

Rigaku XtaLAB mini diffractometer

Absorption correction: multi-scan (REQAB; Rigaku, 1998 ▸) T min = 0.189, T max = 0.257

12561 measured reflections

2732 independent reflections

1881 reflections with I > 2σ(I)

R int = 0.056

Refinement

R[F 2 > 2σ(F 2)] = 0.041

wR(F 2) = 0.092

S = 1.09

2732 reflections

146 parameters

H-atom parameters constrained

Δρmax = 0.50 e Å−3

Δρmin = −0.67 e Å−3

Data collection: CrystalClear-SM Expert (Rigaku, 2011 ▸); cell refinement: CrystalClear-SM Expert; data reduction: CrystalClear-SM Expert; program(s) used to solve structure: SHELXT (Sheldrick, 2015a ▸); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b ▸); molecular graphics: OLEX2 (Dolomanov et al., 2009 ▸); software used to prepare material for publication: OLEX2.

Crystal structure: contains datablock(s) I. DOI: 10.1107/S205698901501909X/lh5792sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S205698901501909X/lh5792Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S205698901501909X/lh5792Isup3.cml

Click here for additional data file.

. DOI: 10.1107/S205698901501909X/lh5792fig1.tif

The asymmetric unit of the title compound. Displacement ellipsoids are drawn at the 50% probability level.

CCDC reference: 1430552

Additional supporting information: crystallographic information; 3D view; checkCIF report

C5H4BrNO	F(000) = 672
Mr = 174.00	Dx = 1.936 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 7.832 (5) Å	Cell parameters from 2269 reflections
b = 18.398 (10) Å	θ = 1.6–27.4°
c = 8.298 (5) Å	µ = 6.77 mm−1
β = 92.906 (5)°	T = 173 K
V = 1194.2 (12) Å3	Prism, colorless
Z = 8	0.3 × 0.3 × 0.2 mm

Rigaku XtaLAB mini diffractometer	2732 independent reflections
Radiation source: Sealed Tube	1881 reflections with I > 2σ(I)
Graphite Monochromator monochromator	Rint = 0.056
Detector resolution: 13.6612 pixels mm-1	θmax = 27.5°, θmin = 2.7°
ω scans	h = −10→10
Absorption correction: multi-scan (REQAB; Rigaku, 1998)	k = −23→23
Tmin = 0.189, Tmax = 0.257	l = −10→10
12561 measured reflections

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.041	w = 1/[σ2(Fo2) + (0.0225P)2 + 1.184P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.092	(Δ/σ)max < 0.001
S = 1.09	Δρmax = 0.50 e Å−3
2732 reflections	Δρmin = −0.67 e Å−3
146 parameters	Extinction correction: SHELXL2014 (Sheldrick, 2015b), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraints	Extinction coefficient: 0.0059 (6)
Primary atom site location: structure-invariant direct methods

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.

	x	y	z	Uiso*/Ueq
Br2	0.67164 (6)	0.60185 (3)	0.12441 (6)	0.0635 (2)
Br1	0.49425 (6)	0.20942 (3)	0.64430 (6)	0.0639 (2)
O2	0.3319 (3)	0.40963 (15)	0.4152 (4)	0.0529 (8)
N2	0.3246 (4)	0.46580 (17)	0.3178 (4)	0.0405 (7)
O1	0.8214 (4)	0.41613 (18)	0.3888 (4)	0.0688 (10)
N1	0.8315 (4)	0.36058 (18)	0.4861 (4)	0.0458 (8)
C6	0.4715 (5)	0.4993 (2)	0.2786 (4)	0.0399 (9)
H6	0.5765	0.4832	0.3222	0.048*
C2	0.6948 (5)	0.2634 (2)	0.6143 (4)	0.0423 (9)
C1	0.6861 (5)	0.3230 (2)	0.5159 (5)	0.0439 (9)
H1	0.5814	0.3380	0.4694	0.053*
C7	0.4632 (5)	0.5572 (2)	0.1741 (5)	0.0419 (9)
C3	0.8487 (6)	0.2403 (2)	0.6878 (5)	0.0494 (10)
H3	0.8548	0.1997	0.7547	0.059*
C10	0.1717 (5)	0.4901 (2)	0.2572 (5)	0.0473 (10)
H10	0.0713	0.4681	0.2873	0.057*
C5	0.9832 (5)	0.3399 (2)	0.5567 (5)	0.0500 (10)
H5	1.0818	0.3659	0.5372	0.060*
C4	0.9919 (5)	0.2807 (2)	0.6567 (5)	0.0519 (11)
H4	1.0970	0.2673	0.7049	0.062*
C8	0.3107 (5)	0.5830 (2)	0.1079 (5)	0.0525 (11)
H8	0.3062	0.6223	0.0375	0.063*
C9	0.1645 (5)	0.5475 (3)	0.1510 (5)	0.0571 (12)
H9	0.0589	0.5628	0.1073	0.069*

	U11	U22	U33	U12	U13	U23
Br2	0.0504 (3)	0.0630 (3)	0.0777 (4)	−0.0142 (2)	0.0089 (2)	0.0102 (2)
Br1	0.0534 (3)	0.0706 (4)	0.0674 (3)	−0.0198 (2)	0.0011 (2)	0.0044 (2)
O2	0.0458 (17)	0.0450 (17)	0.0679 (19)	−0.0009 (13)	0.0033 (15)	0.0144 (14)
N2	0.0385 (19)	0.0358 (18)	0.0471 (18)	0.0008 (14)	0.0014 (15)	0.0007 (14)
O1	0.0456 (19)	0.072 (2)	0.089 (2)	0.0061 (15)	0.0075 (17)	0.0410 (18)
N1	0.0341 (18)	0.049 (2)	0.055 (2)	0.0025 (15)	0.0058 (16)	0.0087 (17)
C6	0.030 (2)	0.044 (2)	0.046 (2)	−0.0008 (16)	−0.0014 (17)	−0.0017 (17)
C2	0.039 (2)	0.047 (2)	0.041 (2)	−0.0045 (18)	0.0027 (18)	−0.0059 (18)
C1	0.034 (2)	0.052 (3)	0.046 (2)	0.0011 (18)	−0.0014 (17)	−0.0006 (19)
C7	0.039 (2)	0.040 (2)	0.047 (2)	−0.0015 (17)	0.0039 (18)	−0.0035 (18)
C3	0.053 (3)	0.046 (2)	0.048 (2)	−0.002 (2)	−0.009 (2)	0.0049 (19)
C10	0.028 (2)	0.054 (3)	0.060 (3)	0.0035 (18)	0.0047 (19)	0.001 (2)
C5	0.030 (2)	0.061 (3)	0.059 (3)	0.0003 (19)	0.0000 (19)	0.006 (2)
C4	0.041 (2)	0.055 (3)	0.058 (3)	0.006 (2)	−0.008 (2)	0.001 (2)
C8	0.046 (3)	0.052 (3)	0.059 (3)	0.010 (2)	0.003 (2)	0.018 (2)
C9	0.039 (2)	0.064 (3)	0.067 (3)	0.014 (2)	−0.006 (2)	0.004 (2)

Br2—C7	1.892 (4)	C1—H1	0.9300
Br1—C2	1.885 (4)	C7—C8	1.373 (5)
O2—N2	1.312 (4)	C3—H3	0.9300
N2—C6	1.359 (5)	C3—C4	1.381 (6)
N2—C10	1.351 (5)	C10—H10	0.9300
O1—N1	1.302 (4)	C10—C9	1.374 (6)
N1—C1	1.365 (5)	C5—H5	0.9300
N1—C5	1.352 (5)	C5—C4	1.369 (6)
C6—H6	0.9300	C4—H4	0.9300
C6—C7	1.373 (5)	C8—H8	0.9300
C2—C1	1.367 (5)	C8—C9	1.380 (6)
C2—C3	1.390 (5)	C9—H9	0.9300
O2—N2—C6	119.6 (3)	C2—C3—H3	121.7
O2—N2—C10	120.0 (3)	C4—C3—C2	116.7 (4)
C10—N2—C6	120.4 (3)	C4—C3—H3	121.7
O1—N1—C1	119.0 (3)	N2—C10—H10	120.0
O1—N1—C5	120.9 (3)	N2—C10—C9	120.0 (4)
C5—N1—C1	120.1 (3)	C9—C10—H10	120.0
N2—C6—H6	120.4	N1—C5—H5	119.9
N2—C6—C7	119.2 (3)	N1—C5—C4	120.2 (4)
C7—C6—H6	120.4	C4—C5—H5	119.9
C1—C2—Br1	119.0 (3)	C3—C4—H4	119.2
C1—C2—C3	121.5 (4)	C5—C4—C3	121.7 (4)
C3—C2—Br1	119.4 (3)	C5—C4—H4	119.2
N1—C1—C2	119.9 (4)	C7—C8—H8	121.7
N1—C1—H1	120.1	C7—C8—C9	116.7 (4)
C2—C1—H1	120.1	C9—C8—H8	121.7
C6—C7—Br2	117.4 (3)	C10—C9—C8	121.4 (4)
C6—C7—C8	122.3 (4)	C10—C9—H9	119.3
C8—C7—Br2	120.3 (3)	C8—C9—H9	119.3
Br2—C7—C8—C9	−179.7 (3)	N1—C5—C4—C3	0.4 (7)
Br1—C2—C1—N1	−176.6 (3)	C6—N2—C10—C9	2.2 (6)
Br1—C2—C3—C4	177.8 (3)	C6—C7—C8—C9	−0.3 (6)
O2—N2—C6—C7	178.8 (3)	C2—C3—C4—C5	−0.8 (6)
O2—N2—C10—C9	−177.9 (4)	C1—N1—C5—C4	0.8 (6)
N2—C6—C7—Br2	179.8 (3)	C1—C2—C3—C4	0.1 (6)
N2—C6—C7—C8	0.4 (6)	C7—C8—C9—C10	1.1 (7)
N2—C10—C9—C8	−2.1 (7)	C3—C2—C1—N1	1.1 (6)
O1—N1—C1—C2	178.3 (4)	C10—N2—C6—C7	−1.4 (5)
O1—N1—C5—C4	−179.0 (4)	C5—N1—C1—C2	−1.6 (6)