Enhancing the Production of Endohedral Fullerenes: a Theoretical Proposal

It has been proposed that in a C60 molecule containing two kinds of isotopes one could selectively excite one of them to open temporary gates in the carbon cage and induce the penetration of different atoms inside the molecule in order to produce endohedral fullerenes. In the present work we calculate, from first principles, the vibrational excitation spectra substituting one and two 12C atoms for 13C isotopes in the C60 molecule. To obtain the force constants between the carbon atoms we performed the second derivatives of the energy calculated within the Hartree-Fock approximation. A comparison of the frequency shifts in the vibrational spectra produced by the isotopes with Raman spectroscopy experiments is also presented.