5,5′,6,6′-Tetramethyl-3,3′-bi-1,2,4-triazine

In the title compound, C10H12N6, the two 5,6-dimethyl-1,2,4-triazine halves of the molecule are related by a centre of symmetry. The two triazine rings are coplanar to within a maximum deviation of 0.013 (2) Å from the mean plane of the ring atoms. In the crystal, molecules form layers parallel to the (100) crystallographic plane. Adjacent layers are held together via a C—H⋯π interaction involving molecules related by an a-glide plane.

In the title compound, C 10 H 12 N 6 , the two 5,6-dimethyl-1,2,4triazine halves of the molecule are related by a centre of symmetry. The two triazine rings are coplanar to within a maximum deviation of 0.013 (2) Å from the mean plane of the ring atoms. In the crystal, molecules form layers parallel to the (100) crystallographic plane. Adjacent layers are held together via a C-HÁ Á Á interaction involving molecules related by an a-glide plane.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FY2014).
In the crystal structure, the molecules of (I) form molecular layers parallel to the (100) crystallographic plane (Fig.   2), with the molecular mean planes being inclined to this plane at an angle of 34.8 (5)°. The layers are held together via C-H···π interaction involving the C51-H151 atoms of the methyl group and the triazine ring from the molecule related by an a-glide plane.

Experimental
The title compound, (I), was prepared by the condensation of oxalhydrazidine with 2,3-butanedione according to the procedure of Dedichen (1936Dedichen ( , 1937. Crystals suitable for X-ray diffraction analysis were grown by slow evaporation of a benzene solution.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
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 > 2sigma(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.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )