2-[(Dimethylamino)methylidene]propanedinitrile

In the title moleclue, C6H7N3, the mean plane of the dimethylamino group [maximum deviation = 0.006 (2) Å] forms a dihedral angle of 7.95 (18)° with the mean plane of the propanedinitrile fragment [maximum deviation = 0.008 (2) Å]. In the crystal, weak C—H⋯N hydrogen bonds link the molecules into a three-dimensional network.

In the title moleclue, C 6 H 7 N 3 , the mean plane of the dimethylamino group [maximum deviation = 0.006 (2) Å ] forms a dihedral angle of 7.95 (18) with the mean plane of the propanedinitrile fragment [maximum deviation = 0.008 (2) Å ]. In the crystal, weak C-HÁ Á ÁN hydrogen bonds link the molecules into a three-dimensional network.

Experimental
In a 50 ml round bottomed flask charged with 3 mmol of malononitrile and 3 mmol of dimethyl formamide dimethylacetal was stirred for 2 -3hrs at room temp. The reaction was monitored by TLC. After completion of the reaction, a precipitate was formed. Finally, the product was filtered and washed with pet ether. Yield: 75%, m.p. 361-363 K.
Diffraction quality single crystals were grown by slow evaporation of an ethanol solution of the title compound at room temperature

Refinement
All H atoms were positioned geometrically and were treated as riding on their parent C atoms, with C-H distances of 0.93-0.96 Å and with U iso (H) = 1.2U eq (C) or 1.5U eq (methyl C).  The molecular structure of (I) with displacement ellipsoids drawn at the 40% probability level. H atoms are shown as small spheres of arbitrary radii.

Figure 2
Part of the crystal structure with dashed lines showing weak intermolecular C-H···N hydrogen bonds.

2-[(Dimethylamino)methylidene]propanedinitrile
Crystal data 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.