Fullerene derivatives embedded in poly(methylmethacrylate): a laser flash photolysis and time-resolved EPR study

Abstract

We have found that the addition of N-methylfulleropyrrolidine to poly(methylmethacrylate) (PMMA), during the thermal polymerization route, produces a new fullerene adduct that has been characterized by time-resolved optical and EPR methods. In fact, a new component appears in the differential absorption spectrum with a lifetime of 350 μs and a maximum at 850 nm besides the typical component due to fullerene adducts centered around 700 nm. The new component has been attributed to a fullerene adduct crosslinked to the PMMA chains, supporting the active role of such a polymer matrix in modifying the optical properties of fullerene. Time-resolved electron paramagnetic resonance (TREPR) spectrum of this new species exhibits zfs parameters and spin polarization that are similar to those observed for a trans3– trans3– trans3 adduct in a toluene matrix.