Intercepting the Disilene-Silylsilylene Equilibrium

Area of Science:

• Organosilicon Chemistry
• Main group element chemistry
• Isomerization reactions

Background:

• Disilenes (R2Si=SiR2) and silylsilylenes (R3Si-SiR) are silicon compounds with distinct bonding.
• The equilibrium between these isomers has been difficult to observe directly, except for the parent H2Si=SiH2.

Purpose of the Study:

• To develop a new method for preparing base-coordinated disilenes with hydride substituents.
• To investigate the control over rearrangement from disilenes to silylsilylenes by varying substituents and coordinating bases.

Main Methods:

• Synthesis of novel base-coordinated disilene adducts.
• Systematic variation of steric bulk of coordinating bases and silicon substituents.
• Density Functional Theory (DFT) calculations to study reaction mechanisms and bonding.

Main Results:

• Successful preparation of base-coordinated disilenes with hydride substituents.
• Demonstrated control over the rearrangement to silylsilylene tautomers.
• Observed preference for 1,2-migration of a trimethylsilyl group over hydrogen migration.

Conclusions:

• The study provides direct observation of disilene-silylsilylene tautomerism.
• The findings reveal substituent effects on migratory preferences in silicon compounds.
• DFT calculations offer mechanistic insights into the observed reactivity and bonding in base-stabilized disilenes.