Perylene Diimide: Versatile Building Blocks for Molecular Self-Assemblies, Folding Motifs, and Reaction-Directing Codes

Perylene diimides (PDIs) have been playing important roles in several active fields. Therefore, we will first review the current methods to modify the skeleton of perylene diimides. Next, PDI self-assemblies and PDI folded nanostructures and chemically restrained PDI nanostructures are presented. Unusual physical properties due to nanostructures formation are discussed including the absorption band intensity reversal and pi-stack red-fluorescence emission. Because of interesting pi-stacked structures, PDI derivatives are considered as potential candidates for photovoltaic applications and organic electronics. More importantly, pi-stacking can be tuned when the dihedral angle of the two naphthalene planes varies, thus resulting in adjusted interacting forces. Such cooperative forces lead to the discovery of molecular code phenomena, which will have profound impact an future bi-molecular reaction designs.