The use of anions to template the formation of new supramolecular entities is a relatively new approach to self-assembly, but one that is expanding the available number of noncovalent and coordinate bonding motifs for the construction of new interlocked materials and new supramolecular nanoarchitectures.1-51, 2, 3, 4, 5 Transition metal directed approaches (e.g., using a transition metal to template catenane formation) rely on the directionality of the coordination sphere of the metal to define the geometry of the new self-assembled entity. Hydrogen bonds to anions are also directional in nature,6 and this, combined with the range of geometries that anions possess, allows them to be used to template a variety of new organic supramolecular species. The range of anion geometries has also allowed anionic species to be employed in templating roles in the formation of inorganic clusters and new materials.

This chapter focuses on “inorganic” systems, subdivided by the type of metal cation used. Readers interested in organic systems are directed to the article on “Anion-Templated Self Assembly: Organic Compounds,” keeping in mind that there are many overlaps between these categories and this division is intended only as an aid to the reader.