Endohedral fullerenes: the importance of electronic, size and shape complementarity between the carbon cages and the corresponding encapsulated clusters

Cage-cluster complementarity is of crucial importance in determining the sizes and structures, as well as the properties of endohedral fullerenes. The encapsulated atoms or clusters, which are typically in a positively charged state, are irreversibly, mechanically, and electrostatically trapped inside the typically negatively charged cages. These rather exotic compounds exhibit exquisitely complementary properties between their components. Here, we present a short overview to show that size and shape are crucial in determining the specific structures that are formed, and the presence of electrostatic interactions result in structural motifs that are never observed for pristine fullerene cages. Copyright (c) 2014 John Wiley & Sons, Ltd.