Astronomical Search of Vinyl Alcohol Assisted by Submillimeter Spectroscopy

We report an extension toward the submillimeter domain of the laboratory spectroscopy of the syn and anti conformers of vinyl alcohol, a species that has been detected once in the interstellar medium, in the massive star-forming region Sagittarius B2­(N) (Turner, B. E.; Apponi, A. Microwave detection of interstellar vinyl alcohol, CH2CHOH. Astrophys. J. 2001, 561, L207−L210, 10.1086/324762). Spectra were recorded with high accuracy (15–20 kHz) between 245 and 310 GHz by a frequency-modulation spectrometer equipped with a pyrolysis cell. Using these spectra and the refined molecular constants, we have searched for vinyl alcohol in the publicly available spectral line surveys from the ASAI [Astrochemical Surveys at Institut de Radioastronomie Millimétrique (IRAM)] Large Project, whose source sample spans the evolutionary range of a solar-type protostar and covering 75–350 GHz (4–1 mm) in frequency. We report non-detections in all nine sources, derive upper limits to the abundance of both conformers of vinyl alcohol, and comment on possible chemical and physical explanations for the non-detections.