TR-EPR of single and double spin-labeled C-60 derivatives in frozen matrices

Time-resolved electron paramagnetic resonance spectra of two single spin-labeled and two double spin-labeled C6o derivatives in frozen solution are recorded with pulsed laser excitation and 100 ns time resolution. Quartet and quintet excited species are detected which arise from the electron spin coupling of the triplet excited fullerene moiety with the unpaired spin(s) of the nitroxide label(s). Despite the similar molecular structure, in both series of single and double labeled derivatives a different behavior was found, which is due to substantial difference of the energy of Exchange coupling