Activation of Nitrogen by Diberyllium Species: Matrix Infrared Spectra and Quantum Chemical Calculations

Herein, we report the investigation of N2 activation mediated by diberyllium species in the presence of H2 or CH4 under low-temperature matrix isolation conditions, yielding novel diberyllium dinitrogen complexes HBe(μ-N)2BeR (R = H, CH3). Comprehensive characterization via matrix isolation infrared spectroscopy and quantum chemical calculations unveils elongated N–N bond length (1.293 Å) and reduced N–N bond order (2.13). Bonding and reaction mechanisms analysis reveal the role of σ/π donation and π backdonation between N2 and transient BeI radicals, generated in situ via Be–Be bond cleavage. These BeI radicals exhibit borylene-like reactivity, enabling N2 binding modes previously exclusive to transition metals. The stability of these complexes is attributed to the aromatic character within the Be(μ-N)2Be framework. This study establishes diberyllium compounds as potent main-group N2 activators, offering fundamental insights into their potential for catalytic applications in small-molecule activation.