Work

CH3OH•+ + CH4 Reaction: Mechanistic Insights and Reaction Rates for Astrochemical and Atmospheric Environments

Year: 2025

Type: article

Abstract: The reaction between methanol radical cations and methane, producing methyl radicals and protonated methanol, is pivotal to both astrochemical and atmospheric processes. Methanol and methane are the most abundant organic molecules in space and Earth’s atmosphere and central to molecular synthesis under different environmental conditions. Here, we present a combined experimental and theoretical investigation of the ion–molecule reaction between CH3OH•+ and CH4. The study explores the reaction mechanism and energetics under ionized conditions utilizing quantum chemical methods and experimental data. The findings reveal that the reaction’s non-thermal behavior becomes pronounced when CH3OH•+ is vibrationally excited by photon absorption above the ionization threshold, as can happen in the presence of ionizing agents like cosmic rays. Conversely, in thermal equilibrium conditions, the reaction accelerates as temperatures decrease, as suggested by canonical rate coefficient calculations. The products can initiate further chemical reactions, shaping molecular networks in the interstellar medium and affecting atmospheric trace gas balances.

Source: Molecules

DOI: 10.3390/molecules30051029

Authors: Mauro Satta, Daniele Catone, Mattea Carmen Castrovilli, Francesca Nicolanti, Antonella Cartoni

Institutions: Institute of Nanostructured Materials, National Research Council, Sapienza University of Rome, Institute of Structure of Matter

Language: English

Topic: Astrophysics and Star Formation Studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,258

Funder: Sapienza Università di Roma