3-[4-(Dimethylamino)benzylideneamino]benzonitrile

The molecule of the title Schiff base, C16H15N3, is non-planar and displays a trans configuration with respect to the C=N double bond. The two benzene rings make a dihedral angle of 49.24 (3)°.

The molecule of the title Schiff base, C 16 H 15 N 3 , is non-planar and displays a trans configuration with respect to the C N double bond. The two benzene rings make a dihedral angle of 49.24 (3) .

3-[4-(Dimethylamino)benzylideneamino]benzonitrile
Hai-Jun Xu, Qin-Ying Tan, Li-Jing Cui and Kun Qian S1. Comment Schiff base compounds have attracted great attention and been extensively investigated in terms of their crystallography and coordination chemistry (Garnovskii et al., 1993). As a continuation of our studies on Schiff-base compounds, we here report the synthesis and crystal structure of the title compound (I).
The molecule displays a trans configuration with respect to the C=N double bond (Fig. 1). The values of the C-C, C=C, C-N and C=N bond distances in (I) are similar to the corresponding bond lengths in 4-(2-Hydroxybenzylideneamino)benzonitrile (Gong & Xu, 2008). The molecule is nonplanar and the dihedral angle between the planes of the two benzene rings is 49.24 (0.03) °.

S2. Experimental
All chemicals were obtained from commercial sources and directly used without further purification. 3-aminobenzonitrile (1.18 g, 10 mmol) and 4-(dimethylamino)benzaldehyde (1.49 g, 10 mmol) were dissolved in ethanol (20 ml). The mixture was heated to reflux for 6 h, then cooled to room temperature overnight and large amounts of a yellow precipitate were formed. Yellow crystals were obtained by recrystallization from ethanol(yield:2.04,82%). 1 H-NMR(CDCl 3 , 300 MHz):

S3. Refinement
All H atoms attached to C were positioned geometrically and treated as riding, with C-H = 0.93 (aromatic), 0.93

Figure 1
A view of the title compound with the atomic numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

3-[4-(Dimethylamino)benzylideneamino]benzonitrile
Crystal data Special details 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 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.