Thus, the calculations show that ∆E ‡ can be lowered by 25 kJ mol -1 over the proxy to the previously reported gallium imide if Ph and C 6 F 5 groups are used as R 1 and R 2 , respectively. This reduction of ∆E ‡ is substantial and will result in a ten-thousand-fold increase in the reaction rate at 300 K. Alternatively, using R 1 --TMS and R 2 --C 6 F 5 makes the C -H activation process 30 kJ mol -1 less exothermic while also lowering the barrier by there are no structures in the set that can lower both the activation barrier and the absolute value of the reaction energy. Next, we explore modifications of the structure of the best candidate (R 1 --Ph and R 2 --C 6 F 5 ) that can further improve the energetics of the C -H bond cleavage.