Executive Summary : | Transition metal complexes have traditionally been known for their diverse reactivity, including their role in small molecule activation and homogeneous catalysis. However, the quest for metal-free and environmentally benign catalysts has led to significant progress in main group chemistry. Kinetic stabilization of sub-valent main group species has resulted in low-valent complexes that actively participate in catalysis. For example, aluminium hydrides have been used for various organic transformations, such as hydroboration of carbonyl compounds. Recently, pincer supported gallium complexes have been described as active catalysts in catalytic reduction of CO₂. Small molecules like H₂, CO₂, NH₃, and CO behave as synthons for value-added chemical products. A six-membered N-heterocyclic Ga species can accomplish both H₂ and NH₃ activation under ambient conditions. The activation of robust N-N triple bond with main group elements remained elusive until Braunschweig and co-workers reported the reduction of N₂ using [(CAAC)DurBBr₂]. Stable cyclic alkyl amino carbenes were found to react reversibly with H₂ and NH₃. Frustrated Lewis Pair (FLPs) have emerged as promising candidates for activating many inert small molecules. The present proposal aims to stabilize reactive low-valent main group elements by implementing suitable acyclic/cyclic coordinating frameworks. Theoretical investigation of the electronic structure of these complexes will aid in exploring their reactivity. A detailed computational study of their catalytic application and comparison with transition metal complexes will provide experimentalists with an impetus to design new and efficient catalysts for small molecule activation and homogenous catalysts. |