One- or Semi-Two-Dimensional Organic Nanocrystals Induced by Directional Supramolecular Interactions

One- or semi-two-dimensional (semi-2-D) nanostructures of a variety of intramolecular charge transfer organic materials have been obtained by using directional dipole−dipole interaction between neighboring molecules as the driving force. It was found that (1) increasing the dipole strength could increase the tendency of directional assembly; (2) introducing an additional dipole component into the molecule, growth in an additional direction could be promoted and lead to the formation of semi-2-D nanostructures; and (3) molecular geometry also affects the growth process of nanostructures, as molecular planarity decreases, rearrangement and stacking between molecules become increasingly difficult, which would hinder the formation of directional nanostructures. In addition, we showed that besides dipole−dipole interaction, strong directional supramolecular interactions such as π−π stacking and hydrogen-bonding interactions are also effective in directing 1-D and semi-2-D nanostructure growth.