Solved Effects on Electronic Structure of C₆₀ and its Intrinsic HUMO-LUMO

The electronic structure of C₆₀ molecules dissolved in different non-polar solvents was investigated by derivative absorption spectroscopy which has an advantage of the improvement of resolution for overlapping absorption bands. Besides the allowed transitions h_u→t_1g, h_g→t_1u and h_u→h_g in the UV region, transitions between the electron-vibration couple states of HOMO and LUMO in the visible region （450~650nm） were determined. The transition energies and the HOMO-LUMO gaps of C₆₀ molecules dissolved in carbon disulfide,benzene, carbon tetrachloride, cyclohexane, n-heptane, n-pentane were determined,respectively, and blue shifts of the transition and the HOMO-LUMO gap were observed. With a linear approximation, the energy parameters, of the electronic structure and HOMO-LUMO gap of the isolated C₆₀ molecule were given by using Maxwell-Garnett effective dielectric model. These parameters can be useful for the theoretical studies of the electronic structure of C₆₀ molecules.