Astrochemistry provides fascinating insights into the connections between alcohols and aldehydes, two important categories of complex organic molecules found in interstellar spaces. In this study, we delve deeper into the chemical relationships between these compounds, particularly focusing on those present in the star-forming region known as Sgr B2 (N).
We conducted an investigation into the gas-phase reactions involving ethanol (CH3CH2OH) and the halogens—specifically fluorine and chlorine. Using Density Functional Theory (DFT) calculations, our objective was to uncover whether feasible chemical pathways exist for converting ethanol into acetaldehyde (CH3CHO) in astrochemical environments. To assess their relevance under actual interstellar conditions, we incorporated the reactions we studied into a comprehensive astrochemical model of Sgr B2 (N).
The findings from our DFT analyses demonstrated that both chlorine and fluorine can interact with ethanol without energy barriers, effectively removing a hydrogen atom. After this initial reaction, the resultant ethanol radicals have the potential to engage in additional reactions with atomic hydrogen, leading to the formation of acetaldehyde through various pathways.
When we integrated these innovative reactions into astrochemical models simulating hot cores, it became evident that they are quite effective under such circumstances, resulting in moderate increases in the presence of CH3CHO during periods when gas-phase ethanol is abundant. Among the ethanol radicals explored in our chemical network, we discovered that the radical CH3CHOH showed the highest levels of abundance in our simulations, comparable to the concentrations of ethanol at certain times modeled.
Overall, our research unveils a unique gas-phase “top-down” connection from alcohols to aldehydes that complements the more widely studied “bottom-up” methods, which involve chemical reactions on grain surfaces that convert aldehydes into alcohols. Furthermore, the outcomes of our astrochemical models indicate that the ethanol radical CH3CHOH might be detectable within the interstellar medium, opening new avenues for exploration.
This work was conducted by Christopher N. Shingledecker, Germán Molpeceres, A. Mackenzie Flowers, Deaton Warren, Emma Stanley, and Anthony Remijan. It has been accepted for publication in "Frontiers in Astronomy and Space Sciences," encompassing 11 pages, 8 figures, and 2 tables.
For those interested in further exploring this topic, you can refer to the citation arXiv:2602.03989 [astro-ph.GA] or access the publication directly at https://doi.org/10.48550/arXiv.2602.03989.
Astrobiology and astrochemistry are at the forefront of unraveling the mysteries of the universe. What do you think about the potential for detecting such radicals in space? Are there implications for understanding the origins of life beyond Earth? Share your thoughts!
