6-Methylpyridin-2-amine

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).

In the title molecule, C 6 H 8 N 2 , 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-HÁ Á ÁN hydrogen bond, forming an inversion dimer, while the other amino H atom participates in N-HÁ Á Á interactions between the dimers, forming layers parallel to (100).

Timofeeva Comment
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), C 6 H 8 N 2 (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-6methyl 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) (Table 1) between the amino group and pyridine ring further consolidate the crystal packing, forming the layers parallel to (100) (Figure 2).

Experimental
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.

Refinement
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 (CH 3 -group) and refined in the riding model with fixed isotropic displacement parameters [U iso (H) = 1.5U eq (C) for the CH 3 -group and 1.2U eq (C) for the CH-groups].

6-Methylpyridin-2-amine
Crystal data C 6 H 8 N 2 M r = 108.14 Monoclinic, P2 1 /c Hall symbol: -P 2ybc a = 9.1006 (11) Å b = 6.2458 (8)  Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.