Collisional Energy Transfer In Ethanimine + He System

Abstract

The ethanimine molecule, CH3CHNH, is one of the prebiotic molecules detected by astronomers in chemically-rich molecular clouds in the Galactic Center. The observations indicate a non-equilibrium distribution of rotational state populations in both the E- and Z-isomers of ethanimine, resulting from the competition between radiative processes and collisions with background gases such as He and H2. Accurate interpretation of these observations requires the use of radiative transfer models with collisional state-to-state transition processes included. Here, in order to compute cross sections for state-to-state transitions in both ethanimine isomers, accurate potential energy surfaces for their interaction with a He atom were constructed and three complimentary methods for inelastic scattering were utilized: full-quantum coupled-channel and coupled-states methods, and the mixed quantum/classical theory. Strong propensities of transitions toward Δka = 0 and either Δj = ±1 (with Δkc = 0, ±1, ±2) or Δj = ±2 (with Δkc = ±2) are reported and the origin of this effect is identified. Small but non-negligible differences between energy transfer in the two isomers, on the order of 10%, were found. The utility of the mixed quantum/classical approach to collisional energy transfer at higher collision energies is discussed.

Department(s)

Chemistry

Comments

Centro de Ecológia Aplicada, Grant DE-SC0025420

International Standard Serial Number (ISSN)

1463-9076

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2026 Royal Society of Chemistry, All rights reserved.

Publication Date

01 Jan 2026

PubMed ID

42460913

Link to Full Text

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