Unveiling the Spectroscopy of Complex Organic Radicals by Exploiting Faraday Rotation at (Sub-)millimeter Wavelengths. Illustration with the Acetonyl Radical.

Radical species constitute the main reactants of numerous chemical reaction networks occurring in diverse environments. Rotationally resolved laboratory data, essential to undertake the detection of these highly reactive species, remain difficult to obtain using conventional high-resolution spectroscopy techniques. In the present work, we exploit a new experimental setup based on the Faraday rotation detection technique which allows us to study the gas phase spectra of relatively large radicals, such as dehydrogenated complex organic molecules (COMs).