ELECTRON TRANSFER PROCESSES OF FULLERENES IN THE GROUND AND EXCITED STATES

摘要

Electron transfer takes place only by mixing the strong electron-donors and fullerenes, which gave the steady-state absorption spectra and EPR spectra of the ion radicals. For higher fullerenes, dianions were formed. From the steady-state measurements, the equilibrium constants of the electron-transfer systems were evaluated. By the laser flash photolysis of such equilibrium solution, the electron transfer rates in the excited state and back-electron transfer rate were evaluated. On combining these kinetic data with the equilibrium data, we can able to evaluate the electron-transfer rate constants in the ground state. When the borate anions were used, the photoinduced electron transfer occurs yielding the anion radicals of fullerenes in steady-state concentration. In such system, fullerenes acts as photosensitizing electron acceptor and electron mediator to oxygen and to alkyl viologen dications.