20-EPN2-111: Proton Radiolysis of Astrochemically Relevant Formamide Ices Using A Formal Statistical Experimental Design
Visit by Perry Hailey of the University of Kent (UK) to TA2.11 Atomki Ice Chamber for Astrophysics / Astrochemistry (ICA) (Hungary).
Dates of visit: 02-22 May 2022
Report Summary:
Formamide (NH2CHO) is of astrobiological interest as it has been identified as a potential precursor to a wide variety of organic compounds essential to life, and many biochemical studies propose it is likely to play a crucial role in the context of the origin of life. Formamide contains an amide functional group which is the principal building block necessary to form chains of amino acids and proteins. Furthermore, it has been identified as a key precursor of a large variety of prebiotic molecules and in the presence of an energy source, it promotes the synthesis of adenine, guanine, cytosine, and uracil, which are the four nucleobases of ribonucleic acid or RNA; it is also a precursor of carboxylic acids, amino acids, and sugars. In summary, the chemical versatility of formamide can lead, under favorable conditions, to the synthesis of many molecules that are key constituents of living organisms. Several studies report the prebiotic synthesis of nucleobases from formamide under relatively warm conditions (i.e. near or above room temperature), there are no reports on the formation of nucleobases from formamide in interstellar ices through the combination of irradiation at astrophysically relevant low temperatures and subsequent thermal processes. A few laboratory based studies have explored formamide irradiation although with in a largely non-systematic manner, typically employing a change One Factor At a Time (OFAT) approach. Additionally, scant attention has been paid to the refractory components from the irradiation which would likely reveal the complex chemistry that emerges.
To investigate the role of cosmic ray induced chemistry, the Atomki Ice Chamber for Astrophysics / Astrochemistry (ICA) was used and ice analogues were prepared in situ by depositing gases and Formamide onto ZnSe substrates at 20 K, where they were monitored in the solid-phase by Fourier Transform Infrared (FTIR) Spectroscopy and QMS monitoring of the gaseous emissions. TPD studies will also be performed from 20 through to 200K and both QMS and FTIR data captured on a temporal basis to allow for univariate and multivariate post data analysis. Refractory components were also be retained for post chiral/achiral analysis.
