Abstract:

In order to obtain a better understanding of the substituent effect on C60 derivatives, the 1H NMR, 13C NMR and cyclic voltammetry of a series of 1,2-H(XPhCH2)C60(X=H,o-CH3,m-CH3,p-CH3,o-Br,m-Br,p-Br) derivatives have been examined. The results show that for NMR, the resonances of methylene protons and the methylene carbon atoms of the benzyls are affected significantly by the o-substituent, while the resonances of the fullerenyl protons and the C60sp3 carbon atoms bonded to the addends are less affected by the o-, m- and p-substituent. As for the cyclic voltammetry, the redox properties of these derivatives are also less affected by the o-, m- and p-position difference of the substituent. However, the redox potentials of the derivatives containing CH3PhCH2— are shifted negatively, and the redox potentials of the derivatives containing BrPhCH2 are shift positively with respect to those of 1,2-H(PhCH2)C60. The results indicate that the inductive effect is probably the dominant factor in affecting the properties of C60 derivatives, which may be explored in modulating the electronic structure of C60 derivatives.

Key words: fullerene derivatives, substituent effect, NMR, cyclic voltammetry