Experimental Characterization of the Energetics of Low-temperature Surface Reactions

Abstract

Astrochemical surface reactions are thought to be responsible for the formation of complex organic molecules, which are of potential importance for the origin of life. In a situation, when the chemical composition of dust surfaces is not precisely known, the fundamental knowledge concerning such reactions gains significance. We describe an experimental technique, which can be used to measure the energy released in reactions of a single pair of reactants. These data can be directly compared with the results of quantum chemical computations leading to unequivocal conclusions regarding the reaction pathways and the presence of energy barriers. It allows for predicting the outcomes of astrochemical surface reactions with higher accuracy compared to that achieved based on gas-phase studies. However, for the highest accuracy, some understanding of the catalytic influence of specific surfaces on the reactions is required. The new method was applied to study the reactions of C atoms with H2, O2, and C2H2. The formation of HCH, CO + O, and triplet cyclic-C3H2 products has been revealed, correspondingly.

References in corpus (7)

• A KInetic Database for Astrochemistry (KIDA)
• Origin of the RNA World: The Fate of Nucleobases in Warm Little Ponds
• Formation of silicon oxide grains at low temperature
• The abundance of C3H2 and other small hydrocarbons in the diffuse interstellar medium
• Carbon in different phases ([CII], [CI], and CO) in infrared dark clouds: Cloud formation signatures and carbon gas fractions
• Influence of surface and bulk water ice on the reactivity of a water-forming reaction
• Ultra-Low-Temperature Reactions of Carbon Atoms with Hydrogen Molecules

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• CoCCoA: Complex Chemistry in hot Cores with ALMA. The chemical evolution of acetone from ice to gas
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