HCSiF and HCSiCl: The First Detection of Molecules with Formal C≡Si Triple Bonds

Area of Science:

• Organosilicon chemistry
• Reaction mechanisms
• Computational chemistry

Background:

• Radical cations are reactive intermediates.
• Silynes are silicon analogs of alkynes, with limited experimental evidence for neutral forms.
• Understanding the structure and reactivity of novel silicon compounds is crucial.

Purpose of the Study:

• To provide the first experimental evidence for the formation of neutral silynes HC≡SiF and HC≡SiCl.
• To investigate the molecular structures of these novel silicon compounds.
• To elucidate the reaction pathways involving silicon-containing radical cations.

Main Methods:

• Neutralization of [C,H,Si,X]+ radical cations (X=F, Cl).
• High-level electronic structure calculations.
• Spectroscopic analysis (implied by experimental evidence).

Main Results:

• Experimental confirmation of neutral silynes HC≡SiF and HC≡SiCl formation.
• Determination of nonlinear molecular geometries for HC≡SiF and HC≡SiCl.
• Validation of computational predictions regarding silyne stability and structure.

Conclusions:

• The neutralization of specific silicon-containing radical cations is a viable route to synthesize neutral silynes.
• Neutral silynes HC≡SiF and HC≡SiCl possess experimentally verified nonlinear structures.
• This study expands the known chemistry of silicon-containing compounds and provides a foundation for future investigations.