N-centered, yet Persistent: Isolation of N2O-Based Radicals through FLP-type Stabilization

Abstract

The electrochemical one-electron reduction of IDipp•N₂O (IDipp = 1,3-bis(2,6diisopropylphenyl)imidazol-2-ylidene) is inherently irreversible, highlighting the short-lived nature of the corresponding radical anion. However, stabilization by Lewis acidic boranes enables electrochemically reversible behavior, unlocking access to stable radical species. These radicals are synthesized via chemical reduction and fully characterized, revealing a highly N-centered nature alongside remarkable persistence at room temperature under an inert atmosphere. A comprehensive investigation of their electronic structure is presented, integrating electron paramagnetic resonance techniques (both continuous-wave and pulsed) with theoretical analysis to provide deeper insight into their properties.