2,3-Di­chloro­pyridine

The complete mol­ecule of the title compound, C₅H₃Cl₂N, is generated by crystallographic twofold symmetry, which forces the pyridine N atom and the opposite C—H group to be statistically disordered. In the crystal, weak aromatic π–π stacking [centroid–centroid separation = 3.805 (4) Å and slippage = 1.704 Å] leads to [100] stacks of mol­ecules. Short Cl⋯Cl contacts [3.334 (3) Å] are also observed.

Related literature

For the biological activity of related compounds, see: Liu et al. (2011). For related structures, see: Ma et al. (2007), Liu & Liu (2011).

Experimental

Crystal data

• C₅H₃Cl₂N

• M_r = 147.98

• Monoclinic, C 2/c

• a = 3.805 (3) Å

• b = 14.196 (12) Å

• c = 10.68 (1) Å

• β = 97.221 (14)°

• V = 572.3 (9) ų

• Z = 4

• Mo Kα radiation

• μ = 1.00 mm⁻¹

• T = 113 K

• 0.36 × 0.04 × 0.04 mm

Data collection

• Rigaku Saturn CCD diffractometer

• Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005) T_min = 0.714, T_max = 0.961

• 2936 measured reflections

• 675 independent reflections

• 541 reflections with I > 2σ(I)

• R_int = 0.044

Refinement

• R[F² > 2σ(F²)] = 0.025

• wR(F²) = 0.054

• S = 1.01

• 675 reflections

• 43 parameters

• 2 restraints

• All H-atom parameters refined

• Δρ_max = 0.31 e Å⁻³

• Δρ_min = −0.19 e Å⁻³

Data collection: CrystalClear (Rigaku/MSC, 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 (Sheldrick, 2008); software used to prepare material for publication: CrystalStructure (Rigaku/MSC, 2005).

Supporting information

S1. Comment

Pyridine derivatives are valuable intermidiates and various biological activities. the structure of 2,3-dichloropyridine was confirmed by X-ray crstallography. For biological activities of related compounds, see: Liu et al. (2011). For related structure, see: Ma et al. (2007), Liu et al. & Liu (2011);

Single-crystal X-ray diffraction analysis reveals that the title compound crystallizes in the monoclinic space group C2/c. As shown in Fig. 1, the pyridine ring is nearly planar [mean deviation = 0.003 Å]. As shown in Fig. 2, the crystal structure is stabilized by van der Waals' interactions.

Related literature

For the biological activity of related compounds, see: Liu et al. (2011). For related structures, see: Ma et al. (2007), Liu & Liu (2011);

S2. Experimental

2,3-dichloropyridine is commercially available. Colourless prisms were grown from ethanol.

S3. Refinement

All the H atoms were positioned geometrically (C—H = 0.93Å) and refined as riding with U_iso(H) = 1.2U_eq(C)

Computing details

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

Figures

	Fig. 1. The molecular structure of (I). Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. Atoms with suffix A are generated by (1–x, y, 3/2–z). Just one orientation of N1 and C3 is shown.
	Fig. 2. The crystal packing for (I) with short Cl···Cl contacts indicated by dashed lines.

2,3-Dichloropyridine

Crystal data

C5H3Cl2N	F(000) = 296
Mr = 147.98	Dx = 1.717 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 985 reflections
a = 3.805 (3) Å	θ = 1.9–27.8°
b = 14.196 (12) Å	µ = 1.00 mm^−1
c = 10.68 (1) Å	T = 113 K
β = 97.221 (14)°	Prism, colorless
V = 572.3 (9) Å^3	0.36 × 0.04 × 0.04 mm
Z = 4

Data collection

Rigaku Saturn CCD diffractometer	675 independent reflections
Radiation source: rotating anode	541 reflections with I > 2σ(I)
Multilayer monochromator	Rint = 0.044
Detector resolution: 14.63 pixels mm^-1	θmax = 27.8°, θmin = 2.9°
ω and ϕ scans	h = −4→4
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2005)	k = −18→18
Tmin = 0.714, Tmax = 0.961	l = −13→13
2936 measured reflections

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)] = 0.025	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.054	All H-atom parameters refined
S = 1.01	w = 1/[σ^2(Fo^2) + (0.022P)^2] where P = (Fo^2 + 2Fc^2)/3
675 reflections	(Δ/σ)max = 0.001
43 parameters	Δρmax = 0.31 e Å^−3
2 restraints	Δρmin = −0.19 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	Occ. (<1)
Cl1	0.26918 (10)	0.32961 (3)	0.61537 (4)	0.02346 (14)
C1	0.3983 (4)	0.43421 (10)	0.69098 (13)	0.0154 (3)
C2	0.2951 (3)	0.51548 (10)	0.63275 (12)	0.0182 (3)	0.50
H2	0.138 (6)	0.514 (2)	0.5570 (16)	0.022*	0.50
N1	0.2951 (3)	0.51548 (10)	0.63275 (12)	0.0182 (3)	0.50
C3	0.3971 (4)	0.59762 (10)	0.69191 (15)	0.0214 (4)
H3	0.312 (4)	0.6559 (8)	0.6561 (15)	0.026*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0279 (3)	0.0201 (2)	0.0216 (2)	−0.00436 (16)	0.00026 (17)	−0.00631 (16)
C1	0.0142 (8)	0.0163 (7)	0.0160 (7)	−0.0009 (6)	0.0031 (6)	−0.0027 (6)
C2	0.0158 (8)	0.0235 (7)	0.0149 (7)	−0.0009 (6)	0.0008 (6)	0.0016 (6)
N1	0.0158 (8)	0.0235 (7)	0.0149 (7)	−0.0009 (6)	0.0008 (6)	0.0016 (6)
C3	0.0184 (9)	0.0185 (8)	0.0269 (9)	0.0015 (6)	0.0012 (7)	0.0073 (7)

Geometric parameters (Å, º)

Cl1—C1	1.7317 (18)	C2—H2	0.943 (10)
C1—C2	1.346 (2)	C3—C3^i	1.382 (3)
C1—C1^i	1.394 (3)	C3—H3	0.951 (9)
C2—C3	1.359 (2)
C2—C1—C1^i	120.97 (9)	C3—C2—H2	122.4 (18)
C2—C1—Cl1	118.07 (12)	C2—C3—C3^i	120.92 (9)
C1^i—C1—Cl1	120.96 (6)	C2—C3—H3	119.8 (10)
C1—C2—C3	118.10 (14)	C3^i—C3—H3	119.1 (10)
C1—C2—H2	119.2 (18)
C1^i—C1—C2—C3	0.5 (3)	C1—C2—C3—C3^i	0.5 (3)
Cl1—C1—C2—C3	−179.84 (12)

Symmetry code: (i) −x+1, y, −z+3/2.