(4E)-N-[(2-Chlorophenyl)methoxy]-1,3-dimethyl-2,6-diphenylpiperidin-4-imine

In the title compound, C26H27ClN2O, the piperidine ring has a chair conformation and all of the ring substituents at Csp 3 atoms occupy equatorial positions. The dihedral angle formed between the phenyl rings is 48.11 (9)°. The chlorobenzene ring occupies a position orthogonal to the methoxy(methylidene)amine residue [N—O—C—C torsion angle = −87.90 (15)°]. The conformation about the imine C=N bond [1.278 (2) Å] is E, and the chloro substituent is anti to the piperidine N atom. Helical supramolecular chains along [010] are sustained by C—H⋯π interactions in the crystal packing.

In the title compound, C 26 H 27 ClN 2 O, the piperidine ring has a chair conformation and all of the ring substituents at Csp 3 atoms occupy equatorial positions. The dihedral angle formed between the phenyl rings is 48.11 (9) . The chlorobenzene ring occupies a position orthogonal to the methoxy(methylidene)amine residue [N-O-C-C torsion angle = À87. 90 (15) ]. The conformation about the imine C N bond [1.278 (2) Å ] is E, and the chloro substituent is anti to the piperidine N atom. Helical supramolecular chains along [010] are sustained by C-HÁ Á Á interactions in the crystal packing.

Experimental
Cg1 and Cg2 are the centroids of the C1-C6 and C15-C20 rings, respectively.
In (I), Fig. 1, the piperidine ring has a chair conformation and all of the ring-substituents occupy equatorial positions. In the bromo derivative (Ramalingan et al., 2012) all but the N-bound substituent, which occupies a bisectional position, also occupy equatorial positions, in accord with (I). The dihedral angle formed between the C15-C20 and C21-C26 phenyl rings is 48.11 (9)°, and each forms a dihedral angle of 64.68 (8) and 72.57 (9)°, respectively, with the chlorobenzene ring, which occupies a position orthogonal to the methoxy(methylidene)amine residue as seen in the N1-O1-C7-C6 torsion angle of -87.90 (15)°. The conformation about the imine C8═N1 bond [1.278 (2) Å] is E. The chloro substituent is anti to the piperidine-N atom.
In the crystal packing, helical supramolecular chains along [0 1 0] are sustained by C-H···π interactions, Fig. 2 and Table 1. These assemble into a three-dimensional architecture without specific intermolecular interactions between the chains, Fig. 3.

Experimental
For full details of the synthesis, refer to Ramalingan et al. (2006). Re-crystallization was performed by slow evaporation of an ethanolic solution of (I) which afforded colourless crystals. M.pt: 361-362 K.

Refinement
Carbon-bound H-atoms were placed in calculated positions [C-H = 0.95-0.99 Å, U iso (H) = 1.2-1.5U eq (C)] and were included in the refinement in the riding model approximation. Owing to poor agreement, two reflections, i.e. (0 1 0) and (1 2 10), were omitted from the final refinement.  The molecular structure of (I) showing the atom-labelling scheme and displacement ellipsoids at the 50% probability level.  A view in projection down the b axis of the unit-cell contents for (I). The C-H···π interactions are shown as purple dashed lines. One chain has been highlighted in space-filling mode. where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max = 0.001 Δρ max = 0.29 e Å −3 Δρ min = −0.28 e Å −3

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.