Mechanism-Driven Design of Catalytic N ₂ Fixation Mediated by Copper Carbenes: From DFT Insights to a Descriptor-Based Predictive Model

While main-group species (e.g., boron, carbenes) have demonstrated stoichiometric N2 activation, catalytic N2 fixation to form value-added N-containing organic compounds remains an outstanding challenge. Here, through detailed density functional theory (DFT) calculations, we report the mechanism-driven design of copper carbene-mediated catalytic N2 fixation. Principal interacting orbital (PIO) analysis reveals that N2 activation proceeds via dominant σ-donation from N2 to the electron-deficient Cu–C moiety, complemented by π-backdonation. These insights lead to the rational design of a complete catalytic cycle that transfers nondiazo carbene precursors (gem-dihaloalkanes) and N2 into N-containing compounds. Furthermore, a quantum descriptor-based multivariate regression model, incorporating electronic descriptors (Hirshfeld charges, PIO contributions), enables quantitative prediction of activation barriers and provides a practical guideline for catalyst designs.