Chiral molecule formation in interstellar ice analogs: alpha-aminoethanol NH 2 CH(CH 3 )OH

Aims. Aminoalcohol molecules such as alpha-aminoethanol NH2CH(CH3)OH may be aminoacid precursors. We attempt to characterize and detect this kind of molecules which is important to establish a possible link between interstellar molecules and life as we know it on Earth. Methods. We use Fourier transform infrared (FTIR) spectroscopy and mass spectrometry to study the formation of alphaaminoethanol NH2CH(CH3)OH in H2O:NH3: CH3CHO ice mixtures. Isotopic substitution with NH3 and ab-initio calculation are used to confirm the identification of alpha-aminoethanol. Results. After investigating the thermal reaction of solid NH3 and acetaldehyde CH3CHO at low temperature, we find that this reaction leads to the formation of a chiral molecule, the alpha aminoethanol NH2CH(CH3)OH. For the first time, we report the infrared and mass spectra of this molecule. We also report on its photochemical behavior under VUV irradiation. We find that the main photoproduct is acetamide (NH2COCH3). Data provided in this work indicates that alpha-aminoethanol is formed in one hour at 120 K and suggests that its formation in warm interstellar environments such as protostellar envelopes or cometary environments is likely.