Photoinduced intermolecular electron transfer in mixtures of oligo(p-phenylene vinylene)s (OPVns, with n = 2-7, the number of phenyl rings) and N-methylfulleropyrrolidine (MP-C-60) is studied in o-dichlorobenzene photoinduced absorption (PIA) spectroscopy is used to show that photoexcitation of MP-C-60 generates the corresponding triplet state, which is quenched in a one-electron reduction reaction by OPVn for n > 2. The electronic transitions of the photogenerated OPVn(+.) radical cations evolve with conjugation length in a near linear relation with 1/n. Charge transfer in these donor-acceptor systems for n > 2 is in full agreement with the calculated change in free energy for charge separation.