The electrochemical reduction of triphenylethylene (TriPE) was studied in dimethylsulfoxide (DMSO) containing 0.1 M tetra-n-butylammonium perchlorate supporting electrolyte through the use of cyclic voltammetry. Experiments were conducted using two different mercury hemisphere electrode sizes (radii 3 and 25 μm) and with TriPE concentrations of 0.50 and 2.00 mM so as to span fully the transition from convergent to linear diffusion and steady state to transient voltammetry. Voltammetric responses obtained display two sucessive reduction waves with formal potentials separated by ca. 290 mV. Taking the diffusion coeffient of TriPE, TriPE and TriPE to be 2.8 × 10 m s , excellent fits between simulation and experiments were obtained across all experimental conditions, with the following DISP2 reaction scheme: Heterogeneous reactions: TriPE+ TriPE k10=0.15cms , =0.5 TriPE + TriPE k20=0.032cms , =0.5 (Ef,20-Ef,10=290mV) Homogeneous reactions: TriPE + TriPE TriPE + TriPE K = 1.3 × 10 , k = 5.0 × 10 mol dm s TriPE →products >1.5×10 , >1.0×10 s where k denotes the standard electrochemical rate constant, α the transfer coefficient, Ef0 the standard formal potential, K the equilibrium constant of the disproportionation reaction, k the rate of the forward reaction of disproportionation, K the equilibrium constant of the decay of TriPE , and k the rate of the forward reaction of the decay of TriPE .