Unveiling the gas phase H₂NCO radical: Laboratory rotational spectroscopy and interstellar searches in the direction of IRAS 16293-2422

Researchers at the Institut des Sciences Moléculaires d’Orsay and partner institutions in Toulouse, Bordeaux and Copenhagen made the first gas-phase laboratory detection of the carbamoyl radical (H₂NCO). This radical is thought to be central to the ice-grain chemistry that forms formamide, acetamide and other interstellar complex organic molecules. They produced it by H-atom abstraction from formamide. Its pure rotational spectrum was recorded up to 660 GHz, with chirped-pulse Fourier-transform spectroscopy at millimetre wavelengths and Zeeman-modulated spectroscopy at submillimetre wavelengths. The resulting spectroscopic parameters were used to search ALMA survey data of the young solar-type protostar IRAS 16293-2422, where the radical was not detected. A Purewave wire-grid polarizer placed after the radiation source improved the submillimetre line profiles.