Final recommendations. Imide D is the best candidate for facile methane activation with its lowest ∆E ‡ and active center protected from the dimerization, albeit with the most exothermic ∆E rxn . Another candidate is the R 1 =TMS R 2 =Ph imide, which has a low ∆E ‡ (103 kJ mol -1 ), does not dimerize easily, with an even less exothermic ∆E dim than D, has a moderate ∆E rxn (Figure ), and may also be synthesized in the manner suggested in Ref. . An even lower barrier for imide A (∆E ‡ = 93kJ mol -1 ) makes it suitable for methane activation if its gallium core is additionally protected with bulky groups against 12