C 3 H 8 O 2 Isomers: Insights into Potential Interstellar Species

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2024-11, Vol.128 (46), p.9964-9971
• Main Authors: Noriega, Lisset, González-Ortiz, Luis Armando, Ortíz-Chi, Filiberto, Quintal, Alan, Ramírez, Sandra I, Merino, Gabriel
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/acs.jpca.4c04804

2-Methoxyethanol, with a formula C H O was recently identified in the massive protocluster NGC 6334I. However, its structural isomers, 1,2-propanediol and 1,3-propanediol, remain undetected despite extensive searches in the Sgr B2 region. In this study, we explored the potential energy surface of the C H O system using CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVTZ calculations, identifying 11 species, with the geminal diols 2,2-propanediol and 1,1-propanediol as the most stable forms. We examined the gas-phase decomposition barrier of these geminal diols and found that 1,1-propanediol is thermodynamically stable at low temperatures (10-150 K). C H O isomers with energies below 30 kcal/mol are relevant to the ISM, as they have been identified or tentatively detected in irradiation experiments of ice analogs of CO, H O, and CH OH.