6-Methyl­pyridin-2-amine

Draguta, S.; Khrustalev, V.N.; Sandhu, B.; Antipin, M.Y.; Timofeeva, T.V.

doi:10.1107/S1600536812047800

organic compounds

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Volume 68| Part 12| December 2012| Page o3466

doi:10.1107/S1600536812047800

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6-Methylpyridin-2-amine

Sergiu Draguta,^a ^* Victor N. Khrustalev,^b Bhupinder Sandhu,^c Mikhail Yu. Antipin ^d and Tatiana V. Timofeeva ^c

^aD. Ghitu Institute of Electronic Engineering and Nanotechnologies, 3/3 Academy str., MD-2028, Chisinau, Republic of Moldova, ^bX-Ray Structural Centre, A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov St, B-334, Moscow 119991, Russian Federation, ^cDepartment of Chemistry & Biology, New Mexico Highlands University, 803 University Avenue, Las Vegas, NM 87701, USA, and ^dDepartment of Chemistry & Biology, New Mexico Highlands University, 803 University Avenue, Las mVegas, NM 87701, USA
^*Correspondence e-mail: sergiudraguta@gmail.com

(Received 16 November 2012; accepted 21 November 2012; online 28 November 2012)

In the title molecule, C₆H₈N₂, the endocyclic angles are in the range 118.43 (9)–122.65 (10)°. The molecular skeleton is planar (r.m.s. deviation = 0.007 Å). One of the two amino H atoms is involved in an N—H⋯N hydrogen bond, forming an inversion dimer, while the other amino H atom participates in N—H⋯π interactions between the dimers, forming layers parallel to (100).

Related literature

For general background to the design of chiral or acentric co-crystals, see: Jacques et al. (1981 ); Miyata (1991 ); Scheiner (1997 ). For related compounds, see: Büyükgüngör & Odabaşoğlu (2006 ); Chtioui & Jouini (2006 ); Ni et al. (2007 ); Dai et al. (2011 ); Waddell et al. (2011 ).

Experimental

Crystal data

C₆H₈N₂
M_r = 108.14
Monoclinic, P 2₁ /c
a = 9.1006 (11) Å
b = 6.2458 (8) Å
c = 10.5598 (13) Å
β = 100.952 (2)°
V = 589.29 (13) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 296 K
0.30 × 0.25 × 0.20 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ) T_min = 0.977, T_max = 0.985
5852 measured reflections
1420 independent reflections
1196 reflections with I > 2σ(I)
R_int = 0.030

Refinement

R[F² > 2σ(F²)] = 0.043
wR(F²) = 0.130
S = 1.00
1420 reflections
82 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

Cg is the centroid of the N1/C2–C6 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2A⋯N1ⁱ	0.896 (17)	2.211 (17)	3.1062 (14)	177.5 (11)
N2—H2B⋯Cgⁱⁱ	0.867 (17)	2.674 (16)	3.4875 (12)	163.5 (11)
Symmetry codes: (i) -x, -y+1, -z+2; (ii) $[-x, y+{\script{1\over 2}}, -z-{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2005 ); cell refinement: SAINT (Bruker, 2001 ); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812047800/cv5366sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812047800/cv5366Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812047800/cv5366Isup3.cml

checkCIF report

Comment top

In supramolecular chemistry, intermolecular non-valent interactions, as a factor responsible for the collective properties of solids, are useful chemical tools to control stability, conformation, and assembly of molecules and thus to design new materials with specific physical and chemical properties (Scheiner, 1997). In particular, the absolute asymmetric synthesis that affords optically active compounds starting from achiral reactants in the absence of any external chiral agents is of significant interest (Jacques et al., 1981). To enable the absolute asymmetric synthesis with a high reliability, it is necessary to predict and obtain chiral crystals through self-assembly of the achiral molecules. Such chiral co-crystals are very important as starting solids for the nonlinear optical materials (Miyata, 1991).

In this paper, we determined the structure of the title compound (I), C₆H₈N₂ (Figure 1), with the purpose to study the strengths and directional propensities of its intermolecular non-bonding interactions and to generate in future the chiral molecular co-crystals on the basis of this compound. The structures of several interesting series with pyridine-2-amino-6-methyl derivatives, including acentric organic salts, have been already reported (Büyükgüngör & Odabaşoǧlu, 2006; Chtioui & Jouini, 2006; Ni et al., 2007; Dai et al., 2011; Waddell et al., 2011).

In the molecule of I, endocyclic angles cover the range 118.43 (9)–122.65 (10)°. The endocyclic angles at the C2 and C6 carbon atoms adjacent to the N1 heteroatom are larger than 120°, and those at the other atoms of the ring are smaller than 120°. All the non-hydrogen atoms lie within the same plane (r.m.s. deviation is 0.007 Å). The N2 atom of the amino group has a slightly pyramidalized configuration (sum of the bond angles is 356°).

In the crystal of I, the pyridine N1 atom serves as the acceptor of the N—H···N hydrogen bond (Table 1) which links two molecules into the centrosymmetric dimer (Figure 2). The intermolecular N—H···π interaction (Table 1) between the amino group and pyridine ring further consolidate the crystal packing, forming the layers parallel to (100) (Figure 2).

Related literature top

For general background, see: Jacques et al. (1981); Miyata (1991); Scheiner (1997). For related compounds, see: Büyükgüngör & Odabaşoǧlu (2006); Chtioui & Jouini (2006); Ni et al. (2007); Dai et al. (2011); Waddell et al. (2011).

Experimental top

The compound I was obtained commercially (Aldrich) as a fine-crystalline powder and purified additionally by filtration. Crystals suitable for the X-ray diffraction study were grown by slow evaporation from chloroform solution.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. Molecular structure of I. Displacement ellipsoids are shown at the 50% probability level. H atoms are presented as small spheres of arbitrary radius.
	Fig. 2. A portion of the crystal packing showing intermolecular N—H···N and N—H···π hydrogen bonds as dashed lines.

6-Methylpyridin-2-amine top

Crystal data top

C₆H₈N₂	F(000) = 232
M_r = 108.14	D_x = 1.219 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2436 reflections
a = 9.1006 (11) Å	θ = 2.3–30.0°
b = 6.2458 (8) Å	µ = 0.08 mm⁻¹
c = 10.5598 (13) Å	T = 296 K
β = 100.952 (2)°	Prism, colourless
V = 589.29 (13) Å³	0.30 × 0.25 × 0.20 mm
Z = 4

Data collection top

Bruker APEXII CCD diffractometer	1420 independent reflections
Radiation source: fine-focus sealed tube	1196 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.030
ϕ and ω scans	θ_max = 28.0°, θ_min = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −12→12
T_min = 0.977, T_max = 0.985	k = −8→8
5852 measured reflections	l = −13→13

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)] = 0.043	Hydrogen site location: difference Fourier map
wR(F²) = 0.130	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ²(F_o²) + (0.082P)² + 0.126P] where P = (F_o² + 2F_c²)/3
1420 reflections	(Δ/σ)_max < 0.001
82 parameters	Δρ_max = 0.32 e Å⁻³
0 restraints	Δρ_min = −0.16 e Å⁻³

Crystal data top

C₆H₈N₂	V = 589.29 (13) Å³
M_r = 108.14	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 9.1006 (11) Å	µ = 0.08 mm⁻¹
b = 6.2458 (8) Å	T = 296 K
c = 10.5598 (13) Å	0.30 × 0.25 × 0.20 mm
β = 100.952 (2)°

Data collection top

Bruker APEXII CCD diffractometer	1420 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	1196 reflections with I > 2σ(I)
T_min = 0.977, T_max = 0.985	R_int = 0.030
5852 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.043	0 restraints
wR(F²) = 0.130	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	Δρ_max = 0.32 e Å⁻³
1420 reflections	Δρ_min = −0.16 e Å⁻³
82 parameters

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

	x	y	z	U_iso*/U_eq
N1	0.17331 (10)	0.50475 (14)	0.92049 (8)	0.0227 (3)
N2	−0.00315 (12)	0.77129 (17)	0.90952 (10)	0.0311 (3)
H2A	−0.0502 (18)	0.693 (3)	0.9607 (16)	0.040 (4)*
H2B	−0.0533 (18)	0.877 (3)	0.8697 (15)	0.038 (4)*
C2	0.11252 (12)	0.68485 (17)	0.86263 (10)	0.0234 (3)
C3	0.16561 (13)	0.77898 (18)	0.75860 (11)	0.0271 (3)
H3	0.1219	0.9029	0.7196	0.033*
C4	0.28303 (13)	0.68378 (19)	0.71621 (10)	0.0281 (3)
H4	0.3191	0.7419	0.6470	0.034*
C5	0.34831 (12)	0.49983 (18)	0.77700 (10)	0.0267 (3)
H5	0.4291	0.4349	0.7500	0.032*
C6	0.29036 (12)	0.41577 (17)	0.87838 (10)	0.0234 (3)
C7	0.35535 (13)	0.21888 (19)	0.94938 (11)	0.0307 (3)
H7A	0.4172	0.2597	1.0298	0.046*
H7B	0.4146	0.1429	0.8980	0.046*
H7C	0.2758	0.1282	0.9656	0.046*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0270 (5)	0.0204 (4)	0.0207 (4)	0.0013 (3)	0.0052 (3)	−0.0013 (3)
N2	0.0372 (6)	0.0251 (5)	0.0331 (5)	0.0101 (4)	0.0122 (4)	0.0046 (4)
C2	0.0256 (5)	0.0207 (5)	0.0233 (5)	−0.0009 (4)	0.0029 (4)	−0.0030 (4)
C3	0.0292 (6)	0.0236 (5)	0.0271 (5)	−0.0005 (4)	0.0018 (4)	0.0045 (4)
C4	0.0271 (6)	0.0331 (6)	0.0240 (5)	−0.0056 (4)	0.0047 (4)	0.0045 (4)
C5	0.0243 (5)	0.0315 (6)	0.0251 (5)	0.0014 (4)	0.0065 (4)	−0.0009 (4)
C6	0.0254 (5)	0.0225 (5)	0.0218 (5)	0.0002 (4)	0.0031 (4)	−0.0027 (4)
C7	0.0351 (6)	0.0269 (6)	0.0316 (6)	0.0078 (5)	0.0098 (5)	0.0031 (4)

Geometric parameters (Å, º) top

N1—C2	1.3476 (14)	C4—C5	1.3929 (16)
N1—C6	1.3496 (13)	C4—H4	0.9300
N2—C2	1.3575 (14)	C5—C6	1.3837 (15)
N2—H2A	0.896 (17)	C5—H5	0.9300
N2—H2B	0.867 (17)	C6—C7	1.5019 (15)
C2—C3	1.4099 (15)	C7—H7A	0.9600
C3—C4	1.3702 (16)	C7—H7B	0.9600
C3—H3	0.9300	C7—H7C	0.9600

C2—N1—C6	118.43 (9)	C6—C5—C4	118.53 (10)
C2—N2—H2A	119.7 (10)	C6—C5—H5	120.7
C2—N2—H2B	120.1 (10)	C4—C5—H5	120.7
H2A—N2—H2B	116.2 (14)	N1—C6—C5	122.65 (10)
N1—C2—N2	116.52 (10)	N1—C6—C7	115.68 (9)
N1—C2—C3	121.96 (10)	C5—C6—C7	121.67 (10)
N2—C2—C3	121.51 (10)	C6—C7—H7A	109.5
C4—C3—C2	118.53 (10)	C6—C7—H7B	109.5
C4—C3—H3	120.7	H7A—C7—H7B	109.5
C2—C3—H3	120.7	C6—C7—H7C	109.5
C3—C4—C5	119.88 (10)	H7A—C7—H7C	109.5
C3—C4—H4	120.1	H7B—C7—H7C	109.5
C5—C4—H4	120.1

C6—N1—C2—N2	−178.81 (9)	C3—C4—C5—C6	1.01 (17)
C6—N1—C2—C3	1.34 (15)	C2—N1—C6—C5	−1.20 (16)
N1—C2—C3—C4	−0.31 (17)	C2—N1—C6—C7	178.40 (9)
N2—C2—C3—C4	179.84 (10)	C4—C5—C6—N1	0.04 (17)
C2—C3—C4—C5	−0.88 (17)	C4—C5—C6—C7	−179.54 (10)

Hydrogen-bond geometry (Å, º) top

Cg is the centroid of the N1/C2–C6 ring.

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···N1ⁱ	0.896 (17)	2.211 (17)	3.1062 (14)	177.5 (11)
N2—H2B···Cgⁱⁱ	0.867 (17)	2.674 (16)	3.4875 (12)	163.5 (11)

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

Experimental details

Crystal data
Chemical formula	C₆H₈N₂
M_r	108.14
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	9.1006 (11), 6.2458 (8), 10.5598 (13)
β (°)	100.952 (2)
V (Å³)	589.29 (13)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.30 × 0.25 × 0.20

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2003)
T_min, T_max	0.977, 0.985
No. of measured, independent and observed [I > 2σ(I)] reflections	5852, 1420, 1196
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.660

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.043, 0.130, 1.00
No. of reflections	1420
No. of parameters	82
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.32, −0.16

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2001), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

Cg is the centroid of the N1/C2–C6 ring.

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···N1ⁱ	0.896 (17)	2.211 (17)	3.1062 (14)	177.5 (11)
N2—H2B···Cgⁱⁱ	0.867 (17)	2.674 (16)	3.4875 (12)	163.5 (11)

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

Acknowledgements

The authors are grateful to the NSF for support via DMR grant 0934212 (PREM) and CHE 0832622.

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CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 12| December 2012| Page o3466

doi:10.1107/S1600536812047800

Open

access