DFT studies of dehydrogenation of ammonia–borane catalyzed by [Ir(ItBu′)2]+: A proton transfer mechanism

The catalytic dehydrogenation of ammonia borane (NH3BH3) with the Ir pincer complex, [Ir(ItBu′)2]+, has been investigated by density functional theory (DFT). A mechanism has been proposed for dehydrogenation process involving three possible pathways: stepwise B–H/N–H activation, concerted B–H/N–H activation and proton transfer mechanism. The facile occurrence of the studied systems was demonstrated by the activation barriers of the rate-determining steps. It was found that the proton transfer pathway is mostly kinetically favorable with the lowest activation barrier of 28.38 kcal/mol.