Abstract
In this manuscript, we provide a theoretical rationalization of the mechanisms that control double H(2) addition to an unsaturated 14 e cationic Ir(III) complex to yield a dihydride Ir(III) complex. Further, we also present two mechanisms that can explain the experimentally observed incorporation of deuterium into the tert-Butyl ((t)Bu) groups of the N-heterocyclic I(t)Bu ligands.