Adsorption of HCN on cosmic silicates : a periodic quantum mechanical study
Bancone, Niccolò (Universitat Autònoma de Barcelona. Departament de Química)
Pantaleone, Stefano (Università degli Studi di Torino. Dipartimento di Chimica)
Ugliengo, Piero (Università degli Studi di Torino. Dipartimento di Chimica)
Rimola Gibert, Albert (Universitat Autònoma de Barcelona. Departament de Química)
Corno, Marta (Università degli Studi di Torino. Dipartimento di Chimica)

Date:	2023
Abstract:	Hydrogen cyanide (HCN) represents a small but widely distributed fraction of the interstellar molecules, and it has been observed in all the environments characterizing the formation of a new planetary system. HCN can polymerize to form biomolecules, including adenine (H5C5N5), and it has drawn attention as a possible precursor of several building blocks of life due to the presence of its polymerization products in meteorites, comets and other asteroidal bodies. To elucidate the potential catalytic role that cosmic silicates have played in these processes, we have investigated, at DFT-PBE level inclusive of a posteriori dispersion correction, the energetic and spectroscopic features of the adsorption of HCN molecules on the most relevant crystalline surfaces of the mineral forsterite (Mg2SiO4), a common silicate constituent of the interstellar core grains and planetary rocky bodies. The results reveal that HCN adsorbs both in molecular and dissociative ways, within a wide range of adsorption energies (-29. 4 to -466. 4 kJ mol-1). Thermodynamic and kinetic results show that dissociative adsorption is dominant already at low temperatures, a fact particularly relevant at the protoplanetary conditions (i. e. , the latest stages in the star system formation process). The simulated spectroscopic features of the studied adducts show a wide range of different degrees of perturbation of C-H and C[triple bond, length as m-dash]N bonds. This finding agrees with previous experimental works, and our results confirm that a complex chemistry is observed when this astrochemically-relevant molecule interacts with Mg2SiO4, which may be associated with a considerable potential reactivity towards the formation of relevant prebiotic compounds.
Grants:	European Commission 865657 European Commission 811312 Agencia Estatal de Investigación PID2021-126427NB-I00
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	Physical chemistry chemical physics, Vol. 25, Issue 39 (October 2023) , p. 26797-26812, ISSN 1463-9084

DOI: 10.1039/d3cp01459b

16 p, 2.2 MB

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