Synthesis of ^MeBICAAC Supported Si(III) Radicals and a Silylone via Reduction Route From ^MeBICAAC‐Si(IV) Precursors

Past one decade has witnessed a tremendous growth in the field of carbene stabilized low-valent silicon compounds unravelling very exciting properties of these molecules. Herein, we have employed a bicyclic (alkyl)(amino)carbene, (^MeBICAAC) to explore the low-valent chemistry of silicon. The reduction of bicyclic (alkyl)(amino)carbene-SiCl₄ complex, [(^MeBICAAC)SiCl₄] (1) with KC₈ afforded low-valent Si complexes, including Si(III) radical [(^MeBICAAC)SiCl₃] (2) and a complex with silicon center in a formal zero-valent state, [(^MeBICAAC)₂Si] (3). Similarly, the reduction of in-situ generated ^MeBICAAC adduct of Me₂SiCl₂ with one equivalent of KC₈ led to the formation of [(^MeBICAAC)SiMe₂Cl] (4) complex having an unpaired electron. These complexes have been characterized by IR, UV-Vis., NMR, HRMS, EPR and their solid-state structures were also elucidated by single crystal X-ray crystallography. Further, DFT calculations revealed the lower energy singlet state for complexes 1, 3 and doublet state for complexes 2, 4.