A second monoclinic polymorph of N-(pyrazin-2-yl)aniline

Abstract

The two aromatic rings in the title compound, C₁₀H₉N₃, are aligned at 23.4 (1)° and the bridging C—N—C angle is 128.9 (1)°. In the crystal structure, intermolecular N—H⋯N hydrogen bonds result in a chain motif, the repeat distance of which is half the b axial length of 8.8851 (3) Å.

Related literature

In the P2₁/c modification, the aromatic rings are aligned at 15.2 (1)°, and the repeat distance of the helical chain is half the b-axial length of 7.8423 (3) Å; see: Wan Saffiee et al. (2008 ▶).

Experimental

Crystal data

• C₁₀H₉N₃

• M _r = 171.20

• Monoclinic,

• a = 8.2194 (3) Å

• b = 8.8851 (3) Å

• c = 11.8395 (4) Å

• β = 104.643 (2)°

• V = 836.56 (5) ų

• Z = 4

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 100 (2) K

• 0.25 × 0.05 × 0.03 mm

Data collection

• Bruker SMART APEX diffractometer

• Absorption correction: none

• 7621 measured reflections

• 1922 independent reflections

• 1389 reflections with I > 2σ(I)

• R _int = 0.045

Refinement

• R[F ² > 2σ(F ²)] = 0.042

• wR(F ²) = 0.113

• S = 1.03

• 1922 reflections

• 122 parameters

• H atoms treated by a mixture of independent and constrained refinement

• Δρ_max = 0.20 e Å⁻³

• Δρ_min = −0.23 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Barbour, 2001 ▶); software used to prepare material for publication: publCIF (Westrip, 2008 ▶).

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯N3i	0.90 (2)	2.17 (2)	3.062 (2)	175 (2)

Symmetry code: (i) .

supplementary crystallographic information

Comment

The cell dimensions of the reported monoclinic P2₁/c modification are: a = 10.0644 (3), b = 7.8423 (3), c = 10.8907 (3) Å; β = 116.439 (2)° (Wan Saffiee et al., 2008). The cell dimensions of the present modification (Scheme I, Fig. 1), after transformation to the standard P2₁/c setting, are: a = 8.2194 (3), b = 8.8851 (3), c = 12.5909 (4) Å, β = 114.525 (2)°.

Experimental

The P2₁/c modification of 2-pyrazinyl-N-aniline (0.10 g, 0.4 mmol), zinc acetate (0.09 g, 0.4 mmol) and water (18 ml) were heated in a 23-ml Teflon-lined Parr bomb at 403 K for 2 days. The bomb was cooled to room temperature at 5 K min^-1. Several faint yellow prisms were picked out manually from the cool solution.

Refinement

Carbon-bound H-atoms were placed in calculated positions (C—H 0.95 Å) and were included in the refinement in the riding model approximation, with U(H) fixed at 1.2U(C). The amino H-atom was located in a difference Fourier map, and was freely refined.

Figures

Fig. 1.

Thermal ellipsoid plot (Barbour, 2001) of C10H9N3 at the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius.

Crystal data

C10H9N3	F(000) = 360
Mr = 171.20	Dx = 1.359 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1282 reflections
a = 8.2194 (3) Å	θ = 2.7–26.1°
b = 8.8851 (3) Å	µ = 0.09 mm−1
c = 11.8395 (4) Å	T = 100 K
β = 104.643 (2)°	Prism, pale yellow
V = 836.56 (5) Å3	0.25 × 0.05 × 0.03 mm
Z = 4

Data collection

Bruker SMART APEX diffractometer	1389 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.045
graphite	θmax = 27.5°, θmin = 2.7°
ω scans	h = −10→10
7621 measured reflections	k = −11→11
1922 independent reflections	l = −15→14

Refinement

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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.113	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ2(Fo2) + (0.0547P)2 + 0.1331P] where P = (Fo2 + 2Fc2)/3
1922 reflections	(Δ/σ)max = 0.001
122 parameters	Δρmax = 0.20 e Å−3
0 restraints	Δρmin = −0.22 e Å−3

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

	x	y	z	Uiso*/Ueq
N1	1.00115 (16)	0.42084 (14)	0.63143 (11)	0.0216 (3)
H1	1.103 (2)	0.377 (2)	0.6527 (15)	0.035 (5)*
N2	0.84988 (15)	0.63197 (14)	0.66840 (11)	0.0230 (3)
N3	1.15770 (16)	0.76478 (14)	0.78284 (11)	0.0228 (3)
C1	0.86787 (18)	0.33136 (16)	0.56827 (12)	0.0193 (3)
C2	0.89595 (19)	0.17682 (17)	0.56499 (13)	0.0254 (4)
H2	1.0021	0.1367	0.6049	0.030*
C3	0.7717 (2)	0.08147 (17)	0.50462 (14)	0.0264 (4)
H3	0.7933	−0.0235	0.5030	0.032*
C4	0.61582 (19)	0.13750 (17)	0.44633 (13)	0.0232 (3)
H4	0.5296	0.0717	0.4058	0.028*
C5	0.58777 (19)	0.29106 (17)	0.44814 (13)	0.0222 (3)
H5	0.4815	0.3305	0.4079	0.027*
C6	0.71238 (18)	0.38836 (16)	0.50783 (13)	0.0211 (3)
H6	0.6916	0.4936	0.5074	0.025*
C7	0.99583 (18)	0.56191 (16)	0.67668 (13)	0.0192 (3)
C8	1.14967 (18)	0.63040 (16)	0.73478 (13)	0.0213 (3)
H8	1.2514	0.5772	0.7393	0.026*
C9	1.00948 (18)	0.83515 (18)	0.77382 (13)	0.0248 (4)
H9	1.0085	0.9325	0.8069	0.030*
C10	0.8604 (2)	0.76892 (17)	0.71788 (14)	0.0254 (4)
H10	0.7592	0.8226	0.7139	0.030*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N1	0.0144 (7)	0.0200 (7)	0.0276 (7)	0.0019 (5)	0.0003 (5)	−0.0014 (5)
N2	0.0173 (6)	0.0230 (7)	0.0272 (7)	0.0004 (5)	0.0027 (5)	−0.0036 (5)
N3	0.0195 (7)	0.0228 (7)	0.0251 (7)	−0.0033 (5)	0.0037 (5)	−0.0011 (5)
C1	0.0180 (7)	0.0205 (7)	0.0193 (7)	−0.0010 (6)	0.0048 (6)	−0.0009 (6)
C2	0.0217 (8)	0.0227 (8)	0.0289 (8)	0.0040 (6)	0.0012 (6)	0.0000 (6)
C3	0.0293 (9)	0.0176 (8)	0.0307 (9)	0.0005 (6)	0.0043 (7)	−0.0019 (6)
C4	0.0217 (8)	0.0233 (8)	0.0244 (8)	−0.0059 (6)	0.0053 (6)	−0.0035 (6)
C5	0.0173 (7)	0.0251 (8)	0.0229 (8)	0.0005 (6)	0.0026 (6)	−0.0006 (6)
C6	0.0195 (8)	0.0190 (7)	0.0237 (8)	0.0005 (6)	0.0031 (6)	−0.0011 (6)
C7	0.0175 (7)	0.0198 (7)	0.0194 (7)	0.0004 (6)	0.0030 (6)	0.0020 (6)
C8	0.0177 (7)	0.0224 (8)	0.0233 (8)	−0.0001 (6)	0.0041 (6)	0.0015 (6)
C9	0.0228 (8)	0.0220 (8)	0.0284 (8)	−0.0016 (6)	0.0047 (6)	−0.0049 (6)
C10	0.0202 (8)	0.0241 (8)	0.0307 (9)	0.0032 (6)	0.0043 (6)	−0.0041 (7)

Geometric parameters (Å, °)

N1—C7	1.3681 (19)	C3—H3	0.9500
N1—C1	1.4061 (19)	C4—C5	1.385 (2)
N1—H1	0.897 (18)	C4—H4	0.9500
N2—C7	1.3330 (18)	C5—C6	1.389 (2)
N2—C10	1.3438 (19)	C5—H5	0.9500
N3—C8	1.3171 (19)	C6—H6	0.9500
N3—C9	1.3494 (19)	C7—C8	1.415 (2)
C1—C6	1.393 (2)	C8—H8	0.9500
C1—C2	1.395 (2)	C9—C10	1.370 (2)
C2—C3	1.379 (2)	C9—H9	0.9500
C2—H2	0.9500	C10—H10	0.9500
C3—C4	1.385 (2)
C7—N1—C1	128.94 (13)	C4—C5—H5	119.4
C7—N1—H1	114.0 (12)	C6—C5—H5	119.4
C1—N1—H1	116.7 (11)	C5—C6—C1	119.86 (14)
C7—N2—C10	115.67 (13)	C5—C6—H6	120.1
C8—N3—C9	116.12 (13)	C1—C6—H6	120.1
C6—C1—C2	118.72 (13)	N2—C7—N1	121.09 (13)
C6—C1—N1	123.92 (13)	N2—C7—C8	120.79 (13)
C2—C1—N1	117.35 (13)	N1—C7—C8	118.11 (13)
C3—C2—C1	120.88 (14)	N3—C8—C7	122.74 (13)
C3—C2—H2	119.6	N3—C8—H8	118.6
C1—C2—H2	119.6	C7—C8—H8	118.6
C2—C3—C4	120.52 (14)	N3—C9—C10	121.23 (14)
C2—C3—H3	119.7	N3—C9—H9	119.4
C4—C3—H3	119.7	C10—C9—H9	119.4
C5—C4—C3	118.88 (14)	N2—C10—C9	123.44 (14)
C5—C4—H4	120.6	N2—C10—H10	118.3
C3—C4—H4	120.6	C9—C10—H10	118.3
C4—C5—C6	121.11 (14)
C7—N1—C1—C6	21.9 (2)	C10—N2—C7—N1	178.88 (14)
C7—N1—C1—C2	−159.27 (15)	C10—N2—C7—C8	0.2 (2)
C6—C1—C2—C3	−1.0 (2)	C1—N1—C7—N2	2.9 (2)
N1—C1—C2—C3	−179.81 (14)	C1—N1—C7—C8	−178.36 (14)
C1—C2—C3—C4	−0.3 (2)	C9—N3—C8—C7	0.0 (2)
C2—C3—C4—C5	1.0 (2)	N2—C7—C8—N3	−0.2 (2)
C3—C4—C5—C6	−0.5 (2)	N1—C7—C8—N3	−178.92 (13)
C4—C5—C6—C1	−0.8 (2)	C8—N3—C9—C10	0.1 (2)
C2—C1—C6—C5	1.5 (2)	C7—N2—C10—C9	0.0 (2)
N1—C1—C6—C5	−179.75 (13)	N3—C9—C10—N2	−0.1 (2)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···N3i	0.90 (2)	2.17 (2)	3.062 (2)	175 (2)

Symmetry codes: (i) −x+5/2, y−1/2, −z+3/2.