In spite of considerable use of carbenes for CO 2 sequestering and conversion, they were unable to attract significant importance for the SO 2 fixation process due to the instability of carbene -SO 2 adduct. Very recently we reported that the modeling of proper carbenes, particularly, N-heterocyclic carbenes, is effective for the sequestering and conversion of SO 2 to valuable chemicals. These carbenes are also highly reactive to N O 2 . The success of these studies motivates us to extend our studies with these carbenes for N 2 activation. Since carbene -SO 2 and carbene -N O 2 reactions are barrierless processes and occur at room temperature, carbene -N 2 reactions may occur at an ambient condition. We further extended our quest to convert the captured N 2 to ammonia. To execute N 2 activation by carbene, initially four carbenes with seven substituents which are depicted in Figure , are tested. Carbene -N 2 reaction is exhibited in Figure . The energy profile diagrams of the nitrogen activation process for different carbenes are constructed.