Chemistry International
Vol. 24, No. 5
September 2002
Highlights
from Pure and Applied Chemistry
Nomenclature
for the C60-Ih and C70-D5h(6) Fullerenes (IUPAC Recommendations
2002)
by W.
H. Powell, F. Cozzi, G. P. Moss, C. Thilgen, R. J.-R. Hwu, and A. Yerin
Pure and Applied Chemistry,
Vol. 74, No. 4, pp. 629- 695 (2002)
Fullerenes
are a new allotrope of carbon characterized by a closed-cage structure
consisting of an even number of three-coordinate carbon atoms devoid
of hydrogen atoms. This class was originally limited to closed-cage
structures with 12 isolated five-member rings, the rest being six-member
rings.
Although
it was recognized that existing organic ring nomenclature could be used
for these structures, the resulting names would be extremely unwieldy
and inconvenient for use. Incorrect von Baeyer ring names have been
published. At the same time it was also recognized that established
organic nomenclature principles could be used, or adapted, to provide
a consistent nomenclature for this unique class of compounds based on
the class name fullerene. However, it was necessary to develop an entirely
new method for uniquely numbering closed-cage systems.
This paper
describes IUPAC recommendations for naming and uniquely numbering the
two most common fullerenes with isolated pentagons, the icosahedral
C60 fullerene and a D5h-C70
fullerene.
|
|
(C60-Ih)[5,6]fullerene
|
(C70-D5h(6))[5,6]fullerene
|
It also
describes recommendations for adapting organic nomenclature principles
for naming fullerenes with nonclosed-cage structures, heterofullerenes,
derivatives formed by substitution of hydrofullerenes, and the fusion
of organic rings or ring systems to the fullerene cage. Finally, the
paper suggests methods for describing structures consisting of two or
more fullerene units and for denoting configurations of chiral fullerenes
and their derivatives.
www.iupac.org/publications/pac/2002/7404/7404x0629.html