Formation of Acetamide in Interstellar Medium
Authors: L. Foo, A. Surànyi, A. Guljas, M. Szőri, J. J. Villar, B. Viskolcz, I. G. Csizmadia, A. Rágyanszki, B. Fiser
Acetamide (C2H5NO) is the largest molecule containing a peptide bond, which is an amine (-NH2) group bonded to a carbonyl (C = O) group, that has yet been detected in interstellar medium (ISM). It is also considered to be a precursor for amino acids (the building blocks of proteins). Formation of acetamide in ISM is believed to occur due based on evidence for the existence of the molecule itself and its component smaller species in ISM. A case study of acetamide is presented here, to introduce a new method to determine its possible formation reaction pathways in ISM based on the molecular formula of a species. All possible species with the same molecular formula as acetamide (C2H5NO) but with different connectivity, the so-called constitutional isomers of the molecule (198 structures, 91 unique species), were created and studied under the extreme conditions of dense molecular clouds. Acetamide was found to be the most stable of the C2H5NO isomer family. Based on the stability of the uni- and bimolecular species, eight reactions were proposed which could led to the formation of acetamide in ISM.