As shown in Figure , the formation of [Me2Al(OMTS)][26,8] ion-pair involves a low energy intermediate which is only 27 kJ mol -1 higher in G-qh-tr than the separated reactants and is electronically more stable. This intermediate has an interesting structure, in which a Me3Al adduct of OMTS is involved in AlMe bridging to a Lewis acidic 26,8 neutral. We have been unable to locate transition structures connecting this intermediate with either starting materials or products. This suggests that the barriers for Me2Al + cleavage are likely low and predominantly entropic in nature for this specific sheet.