In Quest of the Missing CHO Isomers in the Interstellar Medium: A Theoretical Search.

Ethylene glycol (CHO), the only diol detected in the interstellar medium (ISM), is a key component in the synthesis of prebiotic sugars. Its structural isomer, methoxymethanol, has also been found in the ISM. Our results show that neither ethylene glycol (ethane-1,2-diol) nor methoxymethanol is the most stable isomer. Using high-level computational methods, we identified five isomers: two diols, one hydroxy ether, and two peroxides. The geminal diol 1,1-ethanediol (ethane-1,1-diol) is the most stable isomer, although it has not been detected in the ISM, whereas the two peroxides are less stable than the geminal diol by 60 kcal/mol. This study also provides the rotational constants and dipole moment for each conformer of every CHO isomer.