Coupling octupoles in crystals:: The case of the 1,3,5-trinitrobenzene-triphenylene 1:1 molecular co-crystal

A new supramolecular crystal engineering approach toward quadratic nonlinear optics is inferred from an acentric cocrystalline template made of two different bi-dimensional octupolar molecules: trinitrobenzene (TNB) and triphenylene (TP). The resulting 2-D octupolar cocrystalline lattice is proposed as a generic template toward multipolar crystalline engineering studies. X-ray diffraction data evidence parallel stacks with alternating vertically overlapping TNB and TP units, leading to a significant, pi-pi intermolecular charge transfer which cannot be accounted for by an oriented gas model.