Several arylfullerenes, C 70 Ph 2n (n = 1-5), are characterised. Their electrochemical properties, investigated by cyclic voltammetry, are the result of a competition between the electron-withdrawing effect exerted by the phenyl groups and the destabilization of redox orbitals deriving from the saturation of double bonds. C 70 Ph 2 is easier to reduce than C 70 , a feature possibly shared with C 70 Ph 4 that makes these derivatives of C 70 amongst the best electron acceptor molecules so far discovered. In the following derivatives, destabilization prevails, and reductions become increasingly more cathodic along the series. NMR spectroscopy is used to investigate C 70 Ph 2n (n = 1-3). Finally, calculation of the LUMO energies supports the earlier reduction of C 70 Ph 2 and calculations also indicate the layering of the injected charges, in the multiply-reduced species, over concentric shells.

C 60 Ph 5 Cl has electrochemical properties strikingly different from pristine C 60 : the cyclovoltammetric curves show that, in the first reduction peak, two electrons are sequentially and irreversibly injected at the same potential. Analysis of the corresponding kinetics suggests that the carbon-chlorine bond is concomitantly severed and that back-oxidation of the resulting fragments regenerates the pristine fullerene derivative. The different oxidation states of this derivative of C 60 therefore repel and attract the chlorine atom, a property that further adds to the well-known special character of fullerene anions.

No abstract

No abstract

No abstract