Observational studies reveal that complex organic molecules (COMs) can be found in various objects associated with different stages along the star formation process. The identification of COMs in prestellar cores, i.e., environments in which thermally induced chemistry can be excluded and radiolysis is limited by cosmic rays and cosmic ray induced UV-photons, is particularly important as this stage sets up the initial chemical composition from which ultimately stars and planets evolve.. Recent laboratory results demonstrated that molecules as complex as glycolaldehyde and ethylene glycol are efficiently formed on icy dust grains via non-energetic atom addition reactions between accreting H atoms and CO-molecules, a process that dominates surface chemistry during the ‘CO-freeze out stage’ in dense cores. This work (see also figure) will be shortly reviewed as a starting point to demonstrate that a similar mechanism can result in the formation of the biologically relevant molecule glycerol - H2C(OH)(HCOH)CH2OH – a sugar alcohol necessary for the formation of membranes of modern living cells and organelles. Our experimental results are fully consistent with a reaction scheme in which glycerol is formed along a chain of radical-radical and radical-molecule interactions between various reactive intermediates produced upon hydrogenation of CO ice or its hydrogenation products. The tentative identification of the chemically related simple sugar glyceraldehyde - HC(O)(HCOH)CH2OH – is discussed as well. Extending on the results obtained in these studies, the new laboratory findings presented here will show that the proposed reaction mechanism holds much potential to form even more complex sugar alcohols and simple sugars.

Complex organic molecule formation under dark cloud conditions: The laboratory view

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.