Formation of Acetaldehyde on CO-rich Ices

Abstract

The radicals HCO and CH${}_3$ on carbon monoxide ice surfaces were simulated using density functional theory. Their binding energy on amorphous CO ice shows broad distributions, with approximative average values of 500 K for HCO and 200 K for CH${}_3$. If they are located on the surface close to each other (3 to 4 Å), molecular dynamics calculations based on density functional theory show that they can form acetaldehyde (CH${}_3$CHO) or CH${}_4$ + CO in barrier-less reactions, depending on the initial orientation of the molecules with respect to each other. In some orientations, no spontaneous reactions were found, the products remained bound to the surface. Sufficient configurational sampling, inclusion of the vibrational zero point energy, and a thorough benchmark of the applied electronic structure method are important to predict reliable binding energies for such weakly interacting systems. From these results it is clear that complex organic molecules, like acetaldehyde, can be formed by recombination reactions of radicals on CO surfaces.

Accepted in ACS Earth and Space Chemistry

References in corpus (8)

• Formation of methyl formate and other organic species in the warm-up phase of hot molecular cores
• The origin of complex organic molecules in prestellar cores
• Binding energies: new values and impact on the efficiency of chemical desorption
• Experimental evidence for Glycolaldehyde and Ethylene Glycol formation by surface hydrogenation of CO molecules under dense molecular cloud conditions
• Formation of the prebiotic molecule NH${}_2$CHO on astronomical amorphous solid water surfaces: accurate tunneling rate calculations
• Complex organic molecules in diffuse clouds along the line of sight to Sgr B2
• Tunneling Rate Constants for H2CO+H on Amorphous Solid Water Surfaces
• Influence of surface and bulk water ice on the reactivity of a water-forming reaction

Cited by in corpus (19)

• Reactivity of HCO with CH3 and NH2 on Water Ice Surfaces. A Comprehensive Accurate Quantum Chemistry Study
• Formation of COMs through CO hydrogenation on interstellar grains
• Quantum mechanical simulations of the radical-radical chemistry on icy surfaces
• Formation of complex molecules in translucent clouds: Acetaldehyde, vinyl alcohol, ketene, and ethanol via nonenergetic processing of C2H2 ice
• Hydrogenation of accreting C-atoms and CO molecules -- simulating ketene and acetaldehyde formation under dark and translucent cloud conditions
• Formation of complex organic molecules in molecular clouds: acetaldehyde, vinyl alcohol, ketene, and ethanol via the "energetic" processing of C${}_2$H${}_2$ ice
• Formation of complex organic molecules on interstellar CO ices? Insights from computational chemistry simulations
• Revisiting the reactivity between HCO and CH${}_3$ on interstellar grain surfaces
• Neural-Network Assisted Study of Nitrogen Atom Dynamics on Amorphous Solid Water. I. Adsorption & Desorption
• Acetaldehyde binding energies: a coupled experimental and theoretical study
• A cryogenic ice setup to simulate carbon atom reactions in interstellar ices
• Enhanced formation of interstellar complex organic molecules on carbon monoxide ice
• Conformational isomerism of methyl formate: new detections of the higher-energy trans conformer and theoretical insights
• Thermal desorption of astrophysical relevant ice mixtures of acetaldehyde and acetonitrile from olivine dust
• Interstellar Chemistry of CN Radicals on Ices: The formation of CH3CN and CH3NC and potential connection to acetamide
• Hydrogenation of acetaldehyde on interstellar ice analogs reveals limited destruction
• Complex Organic Molecules towards the central molecular zone of NGC 253
• A sensitivity analysis of interstellar ice chemistry in astrochemical models
• Theoretical computations on the efficiency of acetaldehyde formation on interstellar icy grains