Executive Summary : | Due to the high intrinsic reactivity of dinitrogen, many studies have been explored for their activation using transition metal complexes. The development of nitrogen fixation remains the exclusive domain of transition metals because of the availability of their advantageous oxidation-state and orbital diversity, which generally lacks in the other elements of the periodic table. However, transition metals are mostly expensive and toxic in nature, it is highly desirable to develop greener methods for dinitrogen fixation, which can be done by employing the earth-abundant main group elements. Using the concept of main-group metallomimetics i.e. p-block elements reacting in a similar way to transition metals, only one report on dinitrogen activation and reduction at Boron (a p-block element) has been disclosed. Molecular borylene complex with dinitrogen converts N2 to ammonium chloride. In parallel, such small molecule reduction were possible with other main group elements such as Al(I), Si(II), Ga(I), C(II), Ge(II) and Sn(II) molecular compounds. Strikingly, all of them have two unpaired electrons and two vacant orbitals in their atom electronic configuration. Isolobal relationship between these molecules implies the importance of such low valent main group molecules in redox-active catalysis. Active participation of low valent borylene in dinitrogen activation intrigued us to investigate Low valent main group compounds. On the other hand, reduction of nitrous oxide at the main group active centre has been barely explored, due to its low coordinating ability. The importance of nitrous oxide reduction into diazo compounds recently been realized with the help of N-heterocyclic olefins (NHOs). The activated diazoalkenes can be further employed in the activation of CO2 and isocyanide reductions. Hence, the development of main group compounds for the reduction of dinitrogen and nitrous oxide is highly desirable. In this proposal we aim to synthesize low valent main group complexes with wide range of ligands. Highly reactive boron and aluminium based compounds can be realized by employing N2, N2O as reductants and resulting oxidized compounds with main group elements can be isolated in ambient conditions. Such library of molecules will assist in designing a reversible N2 and N2O reduction catalysis. |