organic compounds
6-Methylpyridin-2-amine
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
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
|
Refinement
|
Data collection: APEX2 (Bruker, 2005); cell 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
10.1107/S1600536812047800/cv5366sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812047800/cv5366Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536812047800/cv5366Isup3.cml
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.
The hydrogen atoms of the amino group were localized in the difference-Fourier map and refined isotropically. The other hydrogen atoms were placed in the calculated positions with C—H = 0.93 Å (CH-groups) and 0.96 Å (CH3-group) and refined in the riding model with fixed isotropic displacement parameters [Uiso(H) = 1.5Ueq(C) for the CH3-group and 1.2Ueq(C) for the CH-groups].
Data collection: APEX2 (Bruker, 2005); cell
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).C6H8N2 | F(000) = 232 |
Mr = 108.14 | Dx = 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 |
Bruker APEXII CCD diffractometer | 1420 independent reflections |
Radiation source: fine-focus sealed tube | 1196 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.030 |
ϕ and ω scans | θmax = 28.0°, θmin = 2.3° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | h = −12→12 |
Tmin = 0.977, Tmax = 0.985 | k = −8→8 |
5852 measured reflections | l = −13→13 |
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(Fo2) + (0.082P)2 + 0.126P] where P = (Fo2 + 2Fc2)/3 |
1420 reflections | (Δ/σ)max < 0.001 |
82 parameters | Δρmax = 0.32 e Å−3 |
0 restraints | Δρmin = −0.16 e Å−3 |
C6H8N2 | V = 589.29 (13) Å3 |
Mr = 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)° |
Bruker APEXII CCD diffractometer | 1420 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2003) | 1196 reflections with I > 2σ(I) |
Tmin = 0.977, Tmax = 0.985 | Rint = 0.030 |
5852 measured reflections |
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 | Δρmax = 0.32 e Å−3 |
1420 reflections | Δρmin = −0.16 e Å−3 |
82 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
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* |
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) |
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) |
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 |
Mr | 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) |
Tmin, Tmax | 0.977, 0.985 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5852, 1420, 1196 |
Rint | 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 |
Δρmax, Δρmin (e Å−3) | 0.32, −0.16 |
Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2001), SHELXTL (Sheldrick, 2008).
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.
References
Bruker (2001). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2005). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Büyükgüngör, O. & Odabaşoǧlu, M. (2006). Acta Cryst. E62, o2749–o2750. Web of Science CSD CrossRef IUCr Journals Google Scholar
Chtioui, A. & Jouini, A. (2006). Mater. Res. Bull. 41, 569–575. Web of Science CSD CrossRef CAS Google Scholar
Dai, W.-M., Zhou, H. & Hu, Y.-Q. (2011). Acta Cryst. E67, o578. Web of Science CSD CrossRef IUCr Journals Google Scholar
Jacques, J., Collet, A. & Wilen, S. H. (1981). In Enantiomers, Racemates, and Resolutions. New York: John Wiley & Sons. Google Scholar
Miyata, S. (1991). In Organic Molecules for Nonlinear Optics and Photonics, edited by J. Messier, F. Kajzar & P. Prasad, P. Dordrecht: Kluwer Academic Publishers. Google Scholar
Ni, S.-F., Feng, W.-J., Guo, H. & Jin, Z.-M. (2007). Acta Cryst. E63, o3866. Web of Science CSD CrossRef IUCr Journals Google Scholar
Scheiner, S. (1997). In Molecular Interactions. Chichester: John Wiley & Sons. Google Scholar
Sheldrick, G. M. (2003). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Waddell, P. G., Hulse, J. O. S. & Cole, J. M. (2011). Acta Cryst. C67, o255–o258. Web of Science CSD CrossRef IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
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).