Chemistry Reference
In-Depth Information
with fullerenes which have been classified according to their chemical structures.
This review is completed with the study of endohedral fullerenes, a new family of
fullerenes in which the carbon cage of the fullerene contains a metal, molecule, or
metal complex in the inner cavity. The presence of these species affords new
fullerenes with completely different properties and chemical reactivity, thus open-
ing a new avenue in which a more precise control of the photophysical and redox
properties of fullerenes is possible. The use of fullerenes for organic electronics,
namely in photovoltaic applications and molecular wires, complements the study
and highlights the interest in these carbon allotropes for realistic practical
applications. We have pointed out the so-called non-IPR fullerenes - those that
do not follow the isolated pentagon rule - as the most intriguing class of fullerenes
which, up to now, have only shown the tip of the huge iceberg behind the examples
reported in the literature. The number of possible non-IPR carbon cages is almost
infinite and the near future will show us whether they will become a reality.
Keywords Asymmetric synthesis
Endohedral fullerenes
Fullerenes
Macro-
molecular chemistry
Molecular wires
Non-IPR fullerenes
Organic photovoltaics
Supramolecular chemistry
Contents
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Brief History of Fullerenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 General Remarks on the Chemical Reactivity of Fullerenes . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 New Covalent Chemistry of Fullerenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1 New Reactions on Fullerenes Involving Metals . . . . . . . . . . . . .......................... 8
2.2 Asymmetric Catalysis on Fullerenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.3 Retro-Cycloaddition Reactions of Fullerene Cycloadducts . . . ....................... 13
3 Macromolecular Chemistry of Fullerenes ................................................... 17
3.1 Classification and Synthetic Strategies ................................................ 17
3.2 Properties and Applications . .......................................................... 19
4 Supramolecular Chemistry of Fullerenes ................................................... 23
4.1 H-Bonded Fullerene Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
4.2 On Concave-Convex Interactions . . ................................................... 28
4.3 Tweezers and Macrocycles for the Molecular Recognition of Fullerenes . .......... 32
5 Endohedral Fullerenes: Improving Size, Shape, and Electronic Properties . . . . . . . . . . . . . . . 36
5.1 Metallofullerenes and TNT Endofullerenes ........................................... 38
5.2 Chemical Reactivity of Endohedral Fullerenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
6 Fullerenes for Organic Electronics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
6.1 Fullerenes for Organic Photovoltaics . . . .............................................. 43
6.2 Fullerenes for Molecular Wires . . ..................................................... 45
7 The Future: Non-IPR Fullerenes . . .......................................................... 49
8 Summary, Conclusions, Outlook . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
