The analysis of the 26,9 sheet structure reveals a remarkable finding. The calculated ΔGi-qh-tr value (-55.9 kJ mol -1 ) suggests this species should be approximatively four orders of magnitude more reactive towards OMTS than other MAO structures studied. This predicted exceptional reactivity presents an apparent paradox, given the recent successful isolation and structural characterization of 26,9 (following the addition of nearly 1 equiv. of OMTS to MAO). While the incorporation of neutral precursor stability through ΔΔG-qh-tr/n values moderates the differences, [Me2Al(OMTS)] [26,8] is still predicted to be the most stable ionpair amongst all those studied.