Theoretical investigation of interstellar C-C-O and C-O-C bonding backbone molecules

There are numerous complex organic molecules containing carbon and oxygen atoms which show either C-C-O or C-O-C bonding backbone. This paper examines altogether 51 C-C-O and C-O-C bonding backbone molecules from ten different isomeric groups ( C2H2O, C3H2O, C2H4O, C2H4O2, C3H4O, C2H6O, C2H6O2, C3H6O, C3H6O2, C3H8O) to summarize the present astronomical status of these molecules. Accurate calculations of enthalpy of formation of these molecules show that the isomers with C-C-O backbone are more stable than the C-O-C backbone. Interestingly, a detailed analysis of relevant astromolecules indicates that most of the observed astromolecules have the C-C-O backbone. As a matter of fact, of all the molecules examined in this study, 80% of the astronomically observed species have the C-C-O backbone while only 20% have the C-O-C backbone. In general, interstellar abundance of a molecule is controlled by some factors such as kinetics, formation and destruction pathways, thermodynamics etc. A proper consideration of these factors could explain the observed abundances of these molecules. All these possible key factors are discussed in this paper.