Metamorphosis of activated nitrogen to ammonia at metal-free ambient condition: A DFT based inquisition

Activation of N_2 at an ambient condition and reduction to produce ammonia employing metal-free catalyst is one of the grand scientific problems to date. An effective appetite of carbenes towards molecular nitrogen proclaims their candidature as N_2 sequestering agent. However, the sequestering process is associated with a high activation energy barrier. Thus, to ameliorate the use of carbene for the N 2 activation process a Density Functional Theory (DFT) based design is pursued. Through a systematic study, the binding mechanism of the C − N bond between carbene and nitrogen is explored to model efficient carbene. Additionally, Intrinsic Reaction Coordinate (IRC) geometry traping followed by molecular orbital analysis was employed to explore the electronic level reaction mechanism of diazo derivative formation. It is corroborated that in the carbene − N_2 reaction, carbene operates as a σ -acceptor and π-donor where the bonding and the back bonding processes take place before and after the transition state of the reaction. With the aid of this knowledge, a model carbene is designed and computationally tested for nitrogen activation and ammonia formation. It is observed that the model carbene, 6^CN , is an efficient candidate for nitrogen activation and ammonia synthesis in a catalytic way. These results may stimulate future experimental inquisitions.