Predicting Dinitrogen Activation by Carborane-Based Frustrated Lewis Pairs

Activation of atmospherically abundant dinitrogen (N-2) under mild conditions has been a great challenge in chemistry for decades because of the significantly strong N N triple bond. The traditional strategy of N-2 activation was mainly limited to metallic species until the ground-breaking achievement of N-2 activation by two-coordinated borylenes was achieved experimentally in 2018. On the other hand, carborane derivatives have attracted considerable interest for small-molecule activation. Still, the utilization of carborane derivatives in N-2 activation remains elusive. Here, we design four types of carborane-based frustrated Lewis pairs (FLPs) to probe their potential for N-2 activation by systematical density functional theory calculations. Interestingly, all these carborane-based FLPs are found to become favorable both kinetically and thermodynamically for activating N-2 with low reaction barriers (ranging from 13.0 to 25.8 kcal mol(-1)) and high exothermicity, with Delta G values ranging from -37.5 to -51.0 kcal mol(-1), indicating a high potential for metal-free N2 activation under mild conditions. Our study opens an avenue to metal-free N-2 activation, highlighting the great importance of carborane derivatives in the field of N-2 activation.

Automated summary

This study discusses the challenge of activating dinitrogen (N-2) under mild conditions and introduces the potential of using carborane derivatives for N-2 activation. Through theoretical calculations, it is found that carborane-based frustrated Lewis pairs (FLPs) have low reaction barriers and high exothermicity for N-2 activation, indicating the potential for metal-free N2 activation under mild conditions.