Electronic, Energetic, and Geometric Properties of Methylene-Functionalized C60

Chemical functionalization of C-60 fullerene with one to six carbene (CH2) molecule(s) has been investigated using density functional theory. We have found that the reaction is regioselective so that a CH2 molecule prefers to be adsorbed atop a C-C bond which is shared between two hexagonal rings of the C-60, releasing energy of -3.95 eV. Singly occupied molecular orbital (SOMO) of the CH2 interacts with LUMO of the C-60 via a [2 + 1] cycloaddition reaction. Energy of the reaction and work function of the system are decreased by increasing the number of adsorbed CH2 molecules. The HOMO/LUMO energy gap of C-60 is slightly changed and the electron emission from its surface is facilitated upon the functionalization.