ORIGINAL RESEARCH article
Front. Astron. Space Sci.
Sec. Astrochemistry
This article is part of the Research TopicSeeing that Which Remains Hidden: Tracer and Proxy Species in AstrochemistryView all 6 articles
A gas-phase "top-down" chemical link between aldehydes and alcohols
Provisionally accepted
Christopher Nelson Shingledecker1*
German Molpeceres2
Deaton Warren1
A Mackenzie Flowers3Emma Stanley1
Anthony Remijan4- 1Virginia Military Institute, Lexington city, United States
- 2Fundacion General CSIC, Madrid, Spain
- 3University of Virginia, Charlottesville, United States
- 4National Radio Astronomy Observatory, Charlottesville, United States
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Alcohols and aldehydes represent two key classes of interstellar complex organic molecules (COMs). This work seeks to better understand their possible chemical connections, with a focus on such molecules in the sources of the star-forming region Sgr B2 (N). In particular, we carried out DFT calculations on the gas-phase reaction between ethanol (CH3CH2OH) and the halogens fluorine and chlorine, with the goal of determining whether astrochemically viable chemical pathways leading to acetaldehyde (CH3CHO) exist. These calculations revealed that both chlorine and fluorine can react barrierlessly with ethanol to abstract a hydrogen atom. Following this initial step, the resulting ethanol radicals can undergo further reactions with atomic hydrogen, with some routes leading to acetaldehyde. The studied reactions were then included in an astrochemical model of Sgr B2 (N) to determine their significance under real interstellar conditions. These models showed that the reactions are indeed efficient in hot cores, and can lead to modest increases in the abundance of CH3CHO during model times where gas-phase ethanol is abundant. Regarding the ethanol radicals, we find CH3CHOH to be the most abundant in our simulations, with an abundance comparable to that of ethanol at some times, making this species an attractive target for future study and observational searches in hot cores. Overall, this work reveals a novel gas-phase "top-down" link from alcohols to aldehydes that compliments the better studied "bottom-up" routes involving grain-surface H-addition reactions yielding alcohols from aldehydes.
Keywords: Alcohols, Aldehydes, Astrochemical modeling, astrochemistry, DFT, Halogens, Sgr B2
Received: 11 Jul 2025; Accepted: 03 Dec 2025.
Copyright: © 2025 Shingledecker, Molpeceres, Warren, Flowers, Stanley and Remijan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Christopher Nelson Shingledecker
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.