N2 cleavage by silylene and formation of H2Si(μ-N)2SiH2

Abstract

Fixation and functionalisation of N₂ by main-group elements has remained scarce. Herein, we report a fixation and cleavage of the N ≡ N triple bond achieved in a dinitrogen (N₂) matrix by the reaction of hydrogen and laser-ablated silicon atoms. The four-membered heterocycle H₂Si(μ-N)₂SiH₂, the H₂SiNN(H₂) and HNSiNH complexes are characterized by infrared spectroscopy in conjunction with quantum-chemical calculations. The synergistic interaction of the two SiH₂ moieties with N₂ results in the formation of final product H₂Si(μ-N)₂SiH₂, and theoretical calculations reveal the donation of electron density of Si to π* antibonding orbitals and the removal of electron density from the π bonding orbitals of N₂, leading to cleave the non-polar and strong NN triple bond.