Synthesis of Boryl-Substituted Disilane, Disilene, and Silyl Cation

Reduction of (boryl)­dibromosilane (boryl)­SiHBr2 (1; boryl = B­(NArCH)2, Ar = 2,6-iPr2C6H3) with 2 equiv of potassium graphite in DME at low temperature led to the isolation of bis­(boryl)­disilane (boryl)­SiH2SiH2(boryl) (3) as a colorless solid, whereas reduction of (boryl)­SiPhBr2 (2) in THF gave the boryl-substituted disilene (boryl)­PhSiSiPh­(boryl) (4) as a yellow solid. The reaction of 1 with 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (IiPr) unexpectedly led to the formation of the cationic species [(boryl)­SiHBr­(IiPr)]+Br– (6). These products were characterized by spectroscopic methods as well as by X-ray single-crystal analysis.