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 P 2 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.