Absorption Spectroscopic Study of the Complexation of C_(70) with Aniline and Substituted Anilines

摘要

Complexes of fullerene C_(70) with aniline and various substituted anilines have been studied in CCl_4 medium by electronic absorption spectroscopy. An absorption band due to a charge transfer (CT) transition is observed in the visible region. The experimental CT transition energies are well correlated (through Mulliken's equation) with the ionization potentials (I_D) of the series of anilines studied. From an analysis of this correlation, the electron affinity of C_(70) has been found to be 2.28 eV. The degree of charge transfer in the ground state of the complexes has been found to be very low (0.2-0.3%). The experimentally determined formation constants of the complexes of C_(70) with N-substituted anilines exhibit a very good linear free-energy relationship (Hammett, L. P. Chem. Rev. 1953, 53, 191).