Fullerenes were discovered in 1985 at Rice University and consist of closed hollow cages of carbon atoms arranged in pentagonal and hexagonal rings. The most common fullerene is buckyball (C60), but others include C70, C72, etc. Fullerenes can be produced by vaporizing carbon in a gas medium and spontaneously forming in the condensing vapor. They are very stable due to their structure, with the highest tensile strength of any known material. Research shows fullerenes have applications as strong, resilient materials for armor and inhibiting HIV viruses due to antiviral properties when bonded to other elements.

1. Fullerenes: discovery, properties and applications

2. How did we get to know about fullerenes?Nuclear physics researchers Hahn & Strassman in Germany noticed that carbon cluster ions up to C15+ were produced in a high frequency arc with a graphite electrode in the 1943.

3. A Japanese physical organic chemist E. G. Osawa had perceived that carbon in the single layer closed cages structure would be aromatic and therefore stable, in early 1970.

4. Gal’pern (Russian scientist) had completed the first of many Hückel calculations showing that it would be a closed shell molecule with a large HOMO-LUMO gap in 1973.

5. Fullerenes were discovered experimentally for the first time by a group of scientists at Rice University, Houston, Texas, in September of 1985.What are fullerenes?Fullerenes are closed hollow cages consisting of carbon atoms interconnected in pentagonal and hexagonal rings.

6. Each carbon atom on the cage surface is bonded to three carbon neighbors therefore is sp2 hybridized.

7. The most famous fullerene is C60, known also by “ buckyball ".

8. Other relatively common clusters are C70, C72, C74, C76, C80, C82 and C84 (plenty of others, higher or lower than C60, exist too but less abundant in the experimentally produced mixture fullerene soot). C60C70What are fullerenes? (continued…)

9. Schematic cross-sectional drawing of the supersonic laser-vaporization nozzle used in the discovery of fullerenesHow are fullerenes made?Fullerenes can be made by vaporizing carbon within a gas medium(they could form spontaneously in a condensing carbon vapor)Properties of fullerenesNo other element has such wonderful properties as carbon.

10. Buckyballs are relatively cheap; carbon is everywhere!

11. Even though each carbon atom is only bonded with three other carbons (they are most comfortable with four bonds) in a fullerene molecule, dangling a single carbon atom next to the structure is not strong enough to break the structure of the fullerene molecule.Properties of fullerenes (continued…)In fullerenes, 12 pentagonal rings are necessary and sufficient to effect the cage closure.

12. Fullerenes contain carbon atoms arranged as a combination of 12 pentagonal rings and n hexagonal rings. The chemical formula is C20+2n.

13. Fullerene cages are about 7-15 Å in diameter, and are one carbon atom thick.Properties of fullerenes (continued…)Quite stable from chemical and physical points of view (breaking the balls requires temperatures of about 1000 °C).