Photoinduced Electron Transfer and Adduct Formation between C60/C70 and Optically Active 1,1‘-Binaphthyl-2,2‘-diamine

Abstract

Photoinduced electron transfer and adduct formation between C60/C70 and 1,1‘-binaphthyl-2,2‘-diamine (BNA) have been studied by nanosecond laser flash photolysis and steady-state photolysis as well as circular dichroism measurements. Quantum yields (ΦetT) and rate constants of electron transfer from BNA to the excited triplet state of C60/C70 have been determined by observing the transient absorption bands in the near-IR region where the triplet states and anion radicals of fullerenes appear. Compared with the planar naphthylamine moiety, ΦetT values of perpendicular bichromophoric BNA are low because of hindrance of approach to round fullerenes. The formation of an optically active adduct between C60 and BNA in a polar solvent was observed upon excitation with light at λ > 330 nm where both C60 and BNA are light-absorbing. The reaction mechanism for the optically active adduct formation can be explained as a result of the addition reaction of the N-centered radical formed by deprotonation of BNA•+, which...