Introduction
Haber-Bosch Process: Vital for NH3 production from N2 in agriculture and industry (Fig. 1).
Energy-Intensive Process: High energy consumption and reliance on fossil fuels.
Greenhouse Gas Emissions: Significant contribution to emissions, particularly CO2.
High Temperatures and Pressures: Further intensify energy use and carbon footprint.
Call for Sustainable Alternatives: Urgent need to find greener methods for N2 capture and NH3 production.

Goals and Methods
Goal:
Use computational chemistry to craft boron-based systems capable of potentially activating N2 at room temperature and catalysing its reduction to NH3.
Reasons for Boron:
Widely distributed main group element in both Earth’s crust and in the ocean.
Entry to Group 13 chemistry and transition-metal-free chemistry.
Borylenes of the form [LBR] (Fig. 2) have demonstrated reactivity toward N2.
Computational Methods: Geometries + frequencies: M06-D3/def2-SVP.
Single-point energies: ωB97XD/def2-TZVP.
Implicit solvents (benzene) with PCM.
Concentration correction included for ΔG.
Natural population analyses with NBO.
[B]–N2 bonding situation with EDA-NOCV.

Results and Discussion (Chem. Eur. J. 2022, 28, e2021041 – HOT PAPER)

A – Energy and geometrical correlations
No single geometrical property can account for the energy profile of the distinct [B]–N2 systems.
Strong linear correlations are found between ΔG and the [B]–N2 natural charge at boron, indicating the more negative the natural charge, the larger the exergonicity.

B – EDA-NOCV bonding situation
The interaction between a dicoordinate borylene fragment of the form [LBR] and N2 in a hypothetical complex of the form [LRB(N2)], or [B]–N2, can be envisioned to be similar to that in transition metal dinitrogen complexes (i.e., [LnM–N2], Fig. 4).
EDA-NOCV analysis explored bonding in B–N2 complexes (Fig. 5).
All complexes exhibited substantial ΔEint values.
ΔEelstat contributed 35%-43%, while ΔEorb was the major contributor (57%-64%).
ΔEorb revealed [B]→N2 π-backdonation dominance, with in-plane π component (π||) being the major contributor (32%-54%).
σ-donation played a minor role (17.8%-50%).
Phosphorus-substituted borylenes had higher Pauli repulsion, balanced by electrostatic and orbital interactions, with added benefit from dispersion interactions.
The studied [B]–N2 complexes further benefit from a non-negligible contribution from dispersion interactions (ΔEdisp).

Conclusion
The strategic tuning of the natural charge at boron opens up possibilities for the design of novel borylenes capable of dinitrogen activation and fixation, representing a critical initial step towards catalytic ammonia production involving main group elements.