Abstract
To investigate the magnetic anisotropy effect of C60, thirteen N-acyl fulleropyrrolidines and two N-acyl fulleroazilidines were synthesized and their 1H-NMR analyses were carried out. The protons of fulleropyrrolidine derivatives appeared at low magnetic field compared with those of the corresponding pyrrolidine derivatives. In addition, the downfield shifts correlated strongly with the distances between the protons and the fullerene skeleton. The greater downfield shifts were observed with fulleroazilidine derivatives in which the distances between the protons and the fullerene skeleton are shorter. Comparison of the downfield shifts of fulleropyrrolidine derivatives with those of the corresponding isoindoline derivatives suggested that the magnetic anisotropy effect of C60 is approximately four times greater than that of benzene. These results indicated the possibility of C60 as a tool for structural analysis using NMR.
