NHC-Stabilized Silicon-Carbon Mixed Cumulene

Area of Science:

• Organosilicon Chemistry
• Main Group Chemistry
• Carbene Chemistry

Background:

• Silicon-carbon cumulenes are relatively unexplored due to stability challenges.
• N-heterocyclic carbenes (NHCs) are versatile ligands for stabilizing reactive species.

Purpose of the Study:

• To synthesize and characterize a novel NHC-stabilized silicon-carbon mixed cumulene.
• To investigate the structural and electronic properties of the new compound.
• To explore the reactivity of the silicon-carbon cumulene.

Main Methods:

• Synthesis via reaction of a potassium amide with an NHC-stabilized silene.
• X-ray crystal analysis to determine molecular structure.
• Density Functional Theory (DFT) calculations to probe electronic properties.

Main Results:

• Successful preparation of (Me3Si)2C═Si(IPr)═Si(IPr)═C(SiMe3)2, a C═Si═Si═C cumulene.
• X-ray analysis revealed a short Si-Si double bond distance (2.1896(10) Å).
• DFT calculations indicated a zwitterionic character for the cumulene.
• Reaction with diphenylacetylene yielded a silatriafulvene derivative.

Conclusions:

• The study demonstrates the successful synthesis of a unique silicon-carbon cumulene stabilized by NHCs.
• The compound possesses a distinct C═Si═Si═C cumulene structure with significant zwitterionic character.
• The reactivity studies open possibilities for further exploration in organosilicon chemistry.