Controlling Supramolecular Topology The Art of Building Supermolecules

1 Fullerenes - Carbon Soccer Balls As described above, fullerenes are closed structures constructed from pentagonal and hexagonal carbon units. The fullerene consisting of sixty carbon atoms has a structure similar to a soccer ball. Fullerenes possess very different properties to diamond and graphite some of their electronic properties are somewhat similar to those of a semiconductor. 

2 Carbon Nanotubes - The Smallest Tubular Molecules A carbon nanotube is carbon-based tube with a diameter that is measured in nanometers and a length of several micrometers. Nanotubes have interesting electronic characteristics that are expected to lead to their widespread use in molecular electronics. 

3 Dendrimers - Molecular Trees Dendrimers have systematic branching structures and they are built in a stepwise manner. Supermolecules from this family can be used to shield functional groups and to collect energy. 

4 Rotaxanes-Threading Molecular Rings Rotaxanes are obtained by threading linear polymers through molecular rings such as cyclodextrins, crown ethers and cyclophanes. Molecular shuttles based on the rotaxane structure have been proposed. 

5 Catenanes and Molecular Capsule - Complex Molecular Associations Interlocking several rings results in a catenane structure. Catenanes can be obtained efficiently using supramolecular concepts. The spontaneous formation of a palladiiun coordination complex is an elegant process that is used in the synthesis of catenanes and molecular capsules. 

---