The crystal and molecular structure of three homologue 1,4-terephthalylidene-bis-N-(4′-alkylanilines) (TBAA-n)

The three homologue compounds with the general formula (TBAA-n) crystallize in the following space groups: TBAA-0 : monoclinic, P 2₁ c. a = 7.656(3), b = 6.073(1), c = 16.403(7) Å, β = 91.60(2)°; TBAA-1 : monoclinic, P 2₁ c. a = 7.656(3), b = 6.073(1), c = 16.403(7) Å, β = 91.60(2)°; TBAA-1 : monoklin, P 2₁/n, a = 6.0426(11), b = 7.84171(4), c = 18.2147(31) Å, β = 92.32(1)°; TBAA-2 : orthorhombic, P ben, a = 20.9390(8), b = 14.8876(7), c = 6.2069(1) Å. The structures have been solved by direct methods and refined to R = 0.029, 0.044, and 0.049, respectively. Despite the different conformation of the terminal phenyl rings relative to the central core of the coplanar azomethine groups and the phenyl ring, the molecular packing of the three compounds obeys the same principles in forming the crystal structure.