Electrochemical studies of the products of C-60 gamma-irradiated in cyclohexane were conducted using the frequency response of hydrodynamic modulation at rotating disk electrodes (HMRDE) to determine transport properties by a methodology independent of the concentration of the electroactive species. The diffusion coefficients of C-60 and its gamma-irradiated product were separately determined to be 1.9 x 10(-6) and 0.96 x 10(-6) cm(2)/s, respectively, at 50 degrees C. The estimated Stokes radius of the radiolytic product of C-60 approaches twice that of the fullerene itself. Such a result for gamma-radiolysis in cyclohexane solution is consistent with the formation of cyclohexane adducts and likely some C-60 dimer.