Possibility of reducing the coordinated dinitrogen into ammonia and hydrazine using [Ru-L] (L = triamidoamine) and FLP-H $$_{2}$$ 2 : A DFT study

Abstract

DFT studies have been executed on a hypothetical Ru-triamidoamine complex to understand the possibility of synthesizing ammonia and hydrazine from the dinitrogen at normal temperature and pressure in heptane. In this present study, we utilized the $$\hbox {H}_{2}$$ in the form of FLP- $$\hbox {H}_{2}$$ complex and reacted with Ru-triamidoamine complex. We have added three $$\hbox {H}^{+}$$ and $$\hbox {H}^{-}$$ parts of FLP- $$\hbox {H}_{2}$$ to the Ru complex in a stepwise manner as an alternate way to yield $$\hbox {NH}_{3}$$ / $$\hbox {N}_{2}\hbox {H}_{4}$$ . The catalytic cycle for the formation of $$\hbox {NH}_{3}$$ and $$\hbox {N}_{2}\hbox {H}_{4}$$ were found to be energetically feasible. We have also observed some thermodynamically feasible six coordinate [M]-H intermediates. DFT studies were carried out on the possibility of synthesis of ammmonia and hydrazine from the dinitrogen using Ru-triamidoamine complex via FLP- $$\hbox {H}_{2}$$ under normal experimental conditions. The calculated free energies revealed that the formation of all the intermediates and the transition states are thermodynamically viable. Furthermore, our calculations predicted that the formation of ammmonia is more feasible than hydrazine.