Interstellar enols are formed in plasma discharges of alcohols

Laboratory low-pressure cold plasma discharges, which are used to simulate some hot core environments in the star-forming region, have been investigated by employing single-photon vacuum ultraviolet (VUV) photoionization mass spectrometry. Enols with two to four carbon atoms were detected in plasma discharges of alcohols, indicating that enols can result from alcohol destruction induced by ultraviolet and cosmic radiation and accelerated electrons that are abundant in the interstellar medium. This observation, together with the detection of ethenol toward Sgr B2, suggests that larger enols, such as propenols and butenols, should be in the search list of potential molecular species to be identified in interstellar space. The laboratory experiment presented here shows that VUV photoionization sampling of plasma discharges is a valuable method for guiding the search for new interstellar molecules and helping to understand the transformation mechanism of molecular species of astrochemical significance.