Detection of the HCS radical by far-infrared laser magnetic resonance

Abstract

New far-infrared laser magnetic resonance (LMR) spectra from a free radical containing sulfur have been detected in reactions of fluorine, chlorine and hydrogen atoms with several thio-molecules. The same radical is also produced in the chain reaction between molecular fluorine and (CH₃)₂S₂, (CH₃)₂S and mercaptan. The most extensive and intense LMR spectra were observed on the 108 µm D₂O laser line. Based on chemical tests, isotopic substitution and qualitative spectroscopic considerations these spectra are assigned to the HCS radical. This is the first experimental observation of this radical in either the gas or condensed phases.