In the interstellar medium (ISM), UV processing leads to significant chemical transformations in hydrocarbons. Aliphatic hydrocarbons such as alkanes, commonly formed in evolved stars, undergo dehydrogenation primarily through UV-induced photocleavage of C–C bonds rather than direct hydrogen elimination. This study combines experimental data and ab initio calculations to understand how UV absorption at the H-Lyα emission line (121.6 nm) initiates the transition of alkanes to excited Rydberg states, resulting in the formation of olefinic C=C bonds, crucial precursors to aromatic hydrocarbons. The findings highlight a potential bottom-up pathway for the synthesis of unsaturated and aromatic hydrocarbons in dark clouds of the ISM.
You can find the work published in:
https://doi.org/10.1039/D3NR02564K
Photocleavage of Aliphatic C–C Bonds in the Interstellar Medium, Guillermo Tajuelo-Castilla, Jesús I. Mendieta-Moreno, Mario Accolla, Jesús M. Sobrado, Sofia Canola, Pavel Jelínek, Gary J. Ellis, José Ángel Martín-Gago, and Gonzalo Santoro, Astrophys. J. 965 (2024) 184.