Abstract
Since the early nineties, countless publications have been devoted to the study of possible uses of [60] fullerene (C-60) and its derivatives in the fields of materials and nano-biomedical sciences. However, in spite of the importance of conformers notably from the pharmacological point of view, the cis/trans isomerization of C-60 mono-adducts has been rarely seldom investigated. Here we present the results of DFT calculations of the structural, vibrational and NMR properties of both cis and trans isomers of fulleropyrrolidine mono-adduct obtained by photo-addition of glycine methyl ester to C-60. Taken together, our results have shown that the cis isomer is more stable than the trans one. For the cis conformation, the simulated vibrational spectrum shows a more intense peak at 1298 cm(-1). While C-13 spectra revealed no significant differences between the two isomers as compared to experimental results, the calculated H-1 chemical shifts show a significant difference between the two conformers in both the gas phase and in solution. The trans isomer presents a proton at 5.86 ppm, which is more deshielded than the proton of the cis conformer (5.24 ppm).