2-{5,5-Dimethyl-3-[2-(pyridin-2-yl)ethenyl]cyclohex-2-enylidene}propanedinitrile

The molecule of the title compound, C18H17N3, with the exception of the –C(CH3)2 group, is nearly planar [maximum deviation: 0.208 (4), r.m.s. deviation 0.099 (6) Å] and the disubstituted C atom is displaced by 0.679 (2) Å from the mean plane through the remaining non-H atoms. In the crystal, the packing is stabilized by weak C—H⋯π interactions.

The molecule of the title compound, C 18 H 17 N 3 , with the exception of the -C(CH 3 ) 2 group, is nearly planar [maximum deviation: 0.208 (4), r.m.s. deviation 0.099 (6) Å ] and the disubstituted C atom is displaced by 0.679 (2) Å from the mean plane through the remaining non-H atoms. In the crystal, the packing is stabilized by weak C-HÁ Á Á interactions.

D-HÁ
In the crystal, the packing is stabilized by weak C-H···π between the C9 methylene group of the cyclohexene ring and the symmetry related pyridine ring and Van der Waals forces.

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 > σ(F 2 ) is used only for calculating Rfactors(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 )
x y z U iso */U eq N1  (17)