Ab initio and crystal structures of (E,E)-1,4-diphenylbutadiene:: A new type of arene-arene double T-contact and an interesting interlayer cooperation involving diastereoisomeric contacts

The title compound 1,4-(E,E)-diphenylbutadiene crystallizes in the space group P2(1)/n, and the structure contains three independent molecules A-C with modest twisting about the C-Ph bonds. Each molecule engages in two double face-to-face contacts and in four double T-contacts of a new type. These arene-arene interactions form two-dimensional layers that are stacked in the third dimension. In the new double T-contact, both arenes of each laterally off-set spacer-connected diarene serve as faces or edges in each contact. The occurrence of either one independent molecule (A) in two orientations (+A and -A) or of two independent molecules (B and C) results in two diastereoisomeric double T-contacts in each layer. Molecule A is asymmetric and forms enantiomeric (-A+A) and (-A'+A') layers. The alternation between layers with different pairs of diastereosiomeric double T-contacts allows for reduced surface-matching and better van der Waals interactions between the surfaces of the -A+A (-A'+A') layers and the BC layers.