Catalytic role of HI in the interstellar synthesis of complex organic molecule

Author:

Shuming Yang, Peng Xie, Enwei Liang, Zhao Wang

Keyword:

Astrophysics, Astrophysics of Galaxies, Astrophysics of Galaxies (astro-ph.GA)

journal:

Research in Astronomy and Astrophysics, 23, 055019 (2023)

date:

2023-05-18 16:00:00

Abstract

Using quantum chemical calculations, we model the pathways for synthesizing two purine nucleobases, adenine and guanine, in the gas-phase interstellar environment, surrounded by neutral atomic hydrogen (HI). HI is found active in facilitating a series of fundamental proton transfer processes of organic synthesis, including bond formation, cyclization, dehydrogenation, and H migration. The reactive potential barriers were significantly reduced in the alternative pathways created by HI, leading to a remarkable increase in the reaction rate. The presence of HI also lowered the reactive activation temperature from 757.8 K to 131.5-147.0 K, indicating the thermodynamic feasibility of these pathways in star-forming regions where some of the reactants have been astronomically detected. Our findings suggest that HI may serve as an effective catalyst for interstellar organic synthesis.

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