The reaction of C2F6 with either 1 (∆G ‡ 298K = 30.2 kcal mol -1 ) or 1•(DMAP)2 (∆G ‡ 298K = 38.2 kcal mol -1 ) was calculated to proceed with a higher activation energy barrier than 1•DMAP (Supplementary Information, Figure ). It is likely that polarisation and stretching of the Mg-Mg bond in 1•DMAP compared to the symmetric species leads to enhanced reactivity of this species. NPA charges in Alternative mechanisms including electron-transfer were found to be less accessible by DFT calculations and are less likely to be operating under the reaction conditions (Supplementary Information, Figure , Scheme S12).