A Disilene Base Adduct with a Dative Si-Si Single Bond

Area of Science:

• Inorganic Chemistry
• Organosilicon Chemistry
• Materials Science

Background:

• Disilenes are silicon analogues of alkenes, featuring a silicon-silicon double bond.
• Stabilization of low-coordinate silicon species is crucial for understanding silicon chemistry.
• Base-stabilized silicon compounds offer unique reactivity and structural motifs.

Purpose of the Study:

• To synthesize and characterize a novel base-stabilized disilene.
• To elucidate the bonding and structural features of the new compound.
• To investigate the formation mechanism of the disilene.

Main Methods:

• Experimental synthesis at low temperatures.
• Single-crystal X-ray diffraction for structural determination.
• Quantum-chemical calculations for bonding analysis.

Main Results:

• Formation of a base-stabilized disilene (1) through a disproportionation reaction.
• Unprecedented structure featuring a dative Si→Si single bond (Me2EtN→SiCl2→Si(SiCl3)2).
• Push-pull stabilization achieved through an ambiphilic SiCl2 group acting as an acceptor and donor.

Conclusions:

• The study reveals a novel structure in silicon chemistry with a dative Si→Si bond.
• The push-pull electronic stabilization mechanism is key to the compound's formation and stability.
• A proposed autocatalytic mechanism explains the formation of the disilene from reaction intermediates.