The molecular and crystal structure ofN-(4-n-butyloxybenzylidene)-4′-ethylaniline (4O.2) and the homologueN-(4-n-heptyloxybenzylidene)-4′-hexylaniline (7O.6) have been solved (at room temperature) by direct methods. The crystals of both compounds belong to the triclinic system with space group P1with two molecules per unit cell. 4O.2:a= 5·531(2),b= 7·592(3),c= 19·746(7) Å, α = 86·66(2),β= 88·15(2),γ= 90·29(2)° 7O.6:a= 5·420(2),b= 8·307(3),c= 28·057(7) Å, α = 91·69(2),β= 89·76(2),γ= 108·02(2)°. The structures were refined by full-matrix least-squares calculations toR= 0·036 for 2297 observed reflections for 4O.2 and toR= 0·037 for 2150 reflections for 7O.6. The conformations in the asymmetric units of the two compounds differ considerably: The planes of the two phenyl rings of 4O.2, forming the mesogenic core of the molecule, are twisted at 61·2° to each other and the butoxy group contains agaucheconformation. In contrast the heptoxy chain of 7O.6 forms an alltrans-conformation which lies almost in one plane with the two coplanar phenyl rings. The hexyl group also exists in an extended form, in a plane which is rotated against the plane of the mesogenic unit. The packing in the crystalline state of the two homologues exhibits a layered structure alongc*; in 4O.2 these layers are separated, but in 7O.6 they are interdigitated. The compensation of the dipole moments of the C‒O‒C and C˭N‒C bonds occurs similarly in both structures: molecular orientations parallel to thea, c-plane in which the long axes of the molecules points in the same direction are packed in antiparallel fashion alongb*.