QUANTUM CHEMICAL MODELING OF ASTROCHEMICAL REACTIONS OF C ATOM AND C+ CATION WITH NH₃ BOUND TO AMORPHOUS WATER ICE

Permalink

https://hdl.handle.net/2142/122318

Title: QUANTUM CHEMICAL MODELING OF ASTROCHEMICAL REACTIONS OF C ATOM AND C+ CATION WITH NH₃ BOUND TO AMORPHOUS WATER ICE
Author(s): Woon, David E.
Issue Date: 2023-06-23
Keyword(s): Mini-symposium: Infrared Spectroscopy in the JWST Era
Abstract: Reactions of C atoms and C⁺ cations with NH₃ on water ice were characterized with density function theory using modestly sized water clusters. Both reactions are expected to occur in dense interstellar clouds and in protostellar sources. The neutral C(³P) + NH₃ reaction on ice begins with the formation of triplet CNH₃ via dative bonding involving the 2s² lone pair on nitrogen. Assuming it is not ejected into the gas phase, CNH₃ can subsequently react with one or two H atoms to yield CH₂NH₂ and then CH₃NH₂. The ion-molecule C⁺(²P) + NH₃ reaction on ice begins with charge transfer so that C(³P) reacts with NH₃⁺. The short-lived CNH₃⁺ intermediate, which has a covalent C-N bond, deprotonates to yield the H₂NC radical, which was detected in 2021 toward the dark cloud L483 and other sources. Doublet H₂NC can react with H atoms to yield several different products. The vibrational spectrum of NH₃ on amorphous ice will also be presented.
Publisher: International Symposium on Molecular Spectroscopy
Type of Resource: Text
Language: eng
Handle URL: https://hdl.handle.net/2142/122318
DOI: https://doi.org/10.15278/isms.2023.6851