N,N-Dihexyl-4-[2-(4-nitrophenyl)vinyl]aniline

The title compound, C26H36N2O2, was prepared by Horner olefination of p-dihexylaminobenzaldehyde and diethyl p-nitrobenzylphosphonate. It crystallizes with two independent molecules in the asymmetric unit. Both have similar geometries of the pi-systems but the conformations of all hexyl chains are different. Whereas one hexyl chain of the first molecule shows the typical all-anti conformation, the second is arranged in a gauche-anti-gauche-anti conformation with N-C-C-C, C-C-C-C, C-C-C-C and C-C-C-C torsion angles of -65.1 (4), 167.3 (3), 63.3 (4), and 179.4 (3)degrees. One of the hexyl chains in the other molecule has an anti-anti-gauche-anti conformation [N-C-C-C, C-C-C-C, C-C-C-C and C-C-C-C torsion angles = 179.6 (3), -179.8 (3), -68.7 (5) and -178.8 (4)degrees], the other starts with an anti-gauche-gauche sequence. Molecules A and B are composed of five planar subunits. The angle sums around the N atoms are in the range 356 (2)-360.0 (2)degrees. Torsion angles between these segments do not exceed 4.9 (4)degrees, except for one of the alkyl chains each [molecule A = 26.2 (4)degrees; molecule B = -6.0 (4)degrees]. The high planarity of the molecules and the short aniline C-N bonds [1.385 (3) A in molecule A and 1.378 (3) A in molecule B] indicate a strong electronic coupling through the stilbene unit. One methylene group is disordered over two positions with an occupancy ratio of 0.72:0.28.