Dihydrogen coordinaQon to Int-6 is moderately endergonic and leads to the formaQon of an unstable dihydrogen complex Int-7. Experimental data supports the possible existence of dihydrogen complexes of palladium(II) in a four-coordinate environment. DeprotonaQon of Int-7 by Me3N was calculated to occur through TS-3. TS-3 is the highest barrier on the potenQal energy surface (DG ‡ 373K = 21.9 -26.4 kcal mol -1 ). TS-3 progresses to Int-8 which is stabilised by a hydrogen bond between the liberated ammonium group, Me3NH, and newly formed Pd bromide. Previously it has been demonstrated that hydrogenolysis of dimeric analogues of Int-6 occurs with opQmum yields when conducted in the presence of TMEDA between 50 -100 °C. A significant turnover limiQng contribuQon of the dihydrogen acQvaQon step is consistent with 1 st order behavior in base (number of basic sites) and decreasing reacQon rates with decreased dihydrogen pressure. This step alone does not explain the electronic effects observed across the two different kineQc regimes and needs to be considered alongside migratory inserQon menQoned above as part of a turnover-limiQng sequence.