To gain further insight into the efficiency of these redox processes, Marcus theory was applied to calculate the kinetic barriers (Table .4.1). The terminatory SET with the DABCO cation, which regenerates DABCO for further EDA complexation, has an estimated barrier of +9.3 kcal mol -1 . In contrast, the propagative pathway, involving the direct reduction of the RAE, is much more favourable with an estimated barrier of only +0.4 kcal mol -1 , suggesting that this step is diffusion-controlled at room temperature. This implies that the radical anion exists in very low concentrations and undergoes rapid SET, leading to further fragmentation and chain propagation of the cyclohexyl radical R • .