The fluorescence properties of the phenylated fullerenes C70Ph4, C70Ph6, C70Ph8 and C70Ph10 in room temperature solutions

International audienceThe emission and excitation spectra of four phenylated [70] fullerenes, C70Ph4, C70Ph6, C70Ph8, and C70Ph10 in cyclohexane and toluene solutions have been measured. The fluorescence spectra and related excited state properties are found to depend strongly on the number of attached phenyl groups, but with no systematic trends. Quantum yields and fluorescence lifetimes were measured for C70Ph6, C70Ph8, and C70Ph10, allowing the determination of S1 → S0 radiative transition rates kR. It is found that kR for C70Ph10 is about six times larger than for the other compounds. This is consistent with measured absorbtivities for these compounds. The particular character of C70Ph10 is also manifested by its higher intersystem crossing rate kISC