Related Experiment Video
Updated: Nov 14, 2025

An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation
Published on: November 3, 2016
Identification of the Jahn-Teller active trichlorosiloxy (SiCl3O) free radical in the gas phase
Tony C Smith1, Dennis J Clouthier1
1Ideal Vacuum Products, LLC, 5910 Midway Park Blvd. NE, Albuquerque, New Mexico 87109, USA.
Abstract:
The Ã2A1-X̃2E electronic transition of the jet-cooled trichlorosiloxy (SiCl3O) free radical has been observed for the first time in the 650-590 nm region by laser induced fluorescence (LIF) detection. The radical was produced by a pulsed electric discharge through a mixture of silicon tetrachloride and oxygen in high pressure argon at the exit of a pulsed molecular beam valve. The LIF spectrum shows low frequency intervals, which we assign as activity in the normally forbidden degenerate v5 ' and v6 ' modes, indicative of a significant Jahn-Teller effect in the ground state. Single vibronic level emission spectra show level dependent spin-orbit splittings in the ground state and Jahn-Teller predictable variations depending on which upper state level is pumped. The measured lower state energy levels have been fitted to a Jahn-Teller model that simultaneously includes spin-orbit coupling and linear and quadratic multimode coupling. In SiCl3O, the Jahn-Teller interaction predominates over spin-orbit effects.
More Related Videos
Related Concept Videos
Radical Formation: Homolysis
Radical Reactivity: Nucleophilic Radicals
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
Radical Formation: Elimination
Radical Reactivity: Overview
Radical Reactivity: Electrophilic Radicals

