Publikationsdatum:
2014-06-02
Beschreibung:
In this work, we studied the stability of the glycine molecule in the crystalline zwitterion form, known as α-glycine ( + NH 3 CH 2 COO – ), under the action of heavy cosmic ray analogues. The experiments were conducted in a high vacuum chamber at the heavy-ion accelerator Grand Accélérateur National d'Ions Lourds (GANIL), in Caen, France. The samples were bombarded at two temperatures (14 and 300 K) by 58 Ni 11+ ions of 46 MeV, up to a final fluence of 10 13 ion cm –2 . The chemical evolution of the sample was evaluated in situ using a Fourier Transform Infrared Spectrometer (FTIR). The bombardment at 14 K produced several daughter species, such as OCN – , CO, CO 2 and CN – . The results also suggest the appearance of peptide bonds during irradiation, but this must be confirmed by further experiments. The half-life of glycine in the interstellar medium was estimated to be 7.8 10 3 yr (300 K) and 2.8 10 3 yr (14 K). In the Solar system, the values were 8.4 10 2 yr (300 K) and 3.6 10 3 yr (14 K). It is believed that glycine could be present in space environments that suffered aqueous changes, such as the interiors of comets, meteorites and planetesimals. This molecule is present in the proteins of all living beings. Therefore, studying its stability in these environments will provide further understanding of the role of this species in prebiotic chemistry on Earth.
Print ISSN:
0035-8711
Digitale ISSN:
1365-2966
Thema:
Physik
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