Fullerenes Molecular Allotropes of Carbon

For synthetic chemists, who are interested in the transformation of known and the creation of new matter, elemental carbon as starting material once played a minor role. This situahon changed dramatically when the family of carbon allotropes consisting of the classical forms graphite and diamond became enriched by the fullerenes. In contrast to graphite and diamond, with extended solid state stmctures, fullerenes are spherical molecules and are soluble in various organic solvents, an important requirement for chemical manipulations. 

Compared to small two-dimensional molecules, for example the planar benzene, the structures of these three-dimensional systems are aesthetically appealing. The beauty and the unprecedented spherical architecture of these molecular cages immediately attracted the attention of many scientists. Indeed, Buckminsterfullerene CgQ rapidly became one of the most intensively investigated molecules. For synthetic chemists the challenge arose to synthesize exohedrally modified derivatives, in which the properties of fullerenes can be combined with those of other classes of materials. The following initial questions concerned the derivatiza-tion of fullerenes What kind of reactivity do the fullerenes have Do they behave like a three-dimensional superbenzene What are the structures of exohedral fullerene derivatives and how stable are they  

The lUPAC method of naming Buckminsterfullerene given below is too lengthy and complicated for general use [1]  

This system allows also for the indication of the absolute configuration of inherently chiral fullerenes by introducing the stereodescriptors f C) and f A) ( P = fullerene s = systematic numbering C = clockwise A = anti-clockwise). 

In another nomenclature recommendation it was suggested that fullerenes be named in the same way as annulenes, for which the number of C-atoms is indicated in square brackets in front of the word [4]. For fullerenes the number of C-atoms is accompanied by the point group symmetry and by the number of the isomer (using capital Roman) in cases were there are more than one. This is especially important for higher fullerenes. Thus, for Buckminsterfullerene the full description is 

---