Metal-Free Reduction of Nitrous Oxide via P III /P V ═O Cycling: Mechanistic Insights and Catalytic Performance

The catalytic reduction of nitrous oxide (N₂O) has been achieved through metal-free P^III/P^V═O catalysis. Kinetic analysis revealed that the oxygen transfer reaction to the phosphetane is rate determining. Computational investigations support a reaction mechanism in which the phosphetane catalyst preferentially interacts with the nitrogen terminus of N₂O, leading to the formation of a P-N═N-O intermediate in the cis configuration. Natural population analysis indicates stabilizing interactions between the occupied nonbonding oxygen orbitals and the antibonding orbitals of the phosphetane backbone, facilitating the oxygen atom transfer. Following nitrogen extrusion, the active phosphetane species is regenerated via silane-mediated reduction. The catalytic activity was quantitatively assessed by monitoring the nitrogen evolution through gas chromatography (GC) analysis.