Chemistry Reference
In-Depth Information
Fullerenes form a broad family of carbon nanostructures which, in principle,
must obey the IPR rule as a criteria of stability. The so-called hollow fullerenes
undergo a very rich covalent chemistry affording a wide variety of fullerene
derivatives. In this review we have mainly focussed on those reactions carried out
involving metals as catalysts, which have significantly enhanced the scope of
derivatives prepared so far. Furthermore, in our group we reported the detailed
retro-cycloaddition reaction of well-known fullerenopyrrolidines in a quantitative
manner, thus providing a new protection-deprotection protocol in fullerene chem-
istry. This interesting reaction was later extended to other fullerene cycloadducts.
An important topic is combining the intriguing properties of fullerenes with
those of highly versatile polymers, affording the new interdisciplinary field of
“fullerene polymers.” This field has been reviewed with the most outstanding and
recent advances and applications according to the rational structural classification
given in the text.
The convex surface of fullerenes is an ideal scenario to interact with the concave
surface of different organic molecules. Therefore the supramolecular chemistry of
fullerenes has been presented with special emphasis on H-bonding interactions and
ˀ
concave-convex interactions in which our group has been mainly engaged. This
singular approach has been complemented with the most significant examples in the
search for fullerene receptors from other authors.
Just a few years have been enough to show that the carbon family is much larger
than initially thought and many other forms of carbon, sometimes encapsulating
atoms, molecules, or clusters in their inner cavity (endohedral fullerenes), have
been produced. Although the number of endohedral fullerenes is becoming larger
and larger and new chemical species are placed at the inner cavity of fullerenes, the
most frequent and studied endofullerenes have been presented according to their
properties and chemical
,
ˀ
reactivity,
thus complementing the related hollow
fullerenes.
The applications of fullerenes is an open question which has been mainly
focussed on the use of fullerenes for organic electronics, namely with their use in
organic photovoltaics which, no doubt, represents the most realistic application of
fullerenes, as well as their use in the study of molecular wires. Both topics give an
idea of the interest of these carbon allotropes in the emerging fields of nanoscience
and nanotechnology.
Finally, we have stressed the future of fullerenes on those which are nowadays
considered an almost scientific curiosity, the non-IPR fullerenes. Since they are
thermodynamically less stable than the corresponding fullerenes obeying the IPR
rule, their syntheses as endo- or exohedrically functionalized species is currently a
synthetic challenge and some of the most outstanding examples have been
presented. Since the potential number is huge compared with those known so far,
the history and development of fullerenes might just be in its infancy. The future
will tell us how these and other fullerene species still to come will impact new
technologies based on these new carbon nanoforms.
