Theoretical study of the molecular electrostatic potential of C50

Density functional theory (DFF) calculations on three lower energy isomers Of C-50 were carried out at the B3LYP/6-31G* level. Of the three isomers, two have D-5h symmetry (a singlet state and a triplet state) and the other one has D-3 symmetry. The optimized configurations and electrostatic potential distributions have been obtained. The calculated results show that potential minima V-min(r) inside the sphere occur at the center of the sphere. The most negative value of the effective Mulliken atomic charge and the largest regions with the most negative MEP outside the sphere are localized in the neighborhood of pentagon-pentagon vertex fusions. They constitute the most probable active sites in chemical reactions. Our results offer a possible explanation for protonation and alkylation of C-50 fullerene.