NDI Foldamers, Assemblies and Conformational Switching
Naphthalene tetracarboxylic diimide (NDI) has been used in a number of ways to create folding and assembling supramolecular systems. A brief summary of interactions between aromatic units is presented with an emphasis on using electrostatic principles to predict interaction geometries. As a consequence of the highly polarized carbonyl groups on its periphery, NDI has a propensity to self-stack in a characteristic off-set parallel fashion, while preferring an alternating face-centered stacking geometry with complementary, electron rich aromatic moieties such as dialkoxyl naphthalene (DAN) units. This ability to shift between self-stacking and alternating stacking with electron-rich units is now the basis for a growing list of NDI-based supramolecular complexes and assemblies that can undergo predictable conformational switching.