Isomers of hydrogenated polycyclic aromatic hydrocarbons explain the presence of infrared bands in the 3 μm region

A large number of hydrogenated coronene, circumcoronene, and circumcircumcoronene isomers have been investigated by means of density functional theory calculations. The computation of their IR spectra puts forward significant differences between the different isomers in the 3 μm region and shows tha...

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Detalles Bibliográficos
Autores: Pla Terrada, Paula, Wang, Yang, Martín García, Fernando, Alcamí Pertejo, Manuel
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/708920
Acceso en línea:http://hdl.handle.net/10486/708920
https://dx.doi.org/10.3847/1538-4357/ab9cb4
Access Level:acceso abierto
Palabra clave:Polycyclic aromatic hydrocarbons
Spectral line identification
Line positions
Molecular spectroscopy
Cosmochemistry
Química
Descripción
Sumario:A large number of hydrogenated coronene, circumcoronene, and circumcircumcoronene isomers have been investigated by means of density functional theory calculations. The computation of their IR spectra puts forward significant differences between the different isomers in the 3 μm region and shows that hydrogenated polycyclic aromatic hydrocarbons can account for the aromatic infrared bands resulting from the absorption of light by the interstellar medium. In particular, the intense 3.3 μm band, as well as the weak features observed at 3.40, 3.46, 3.51, and 3.56 μm are reasonably reproduced by the present calculations. The latter two are only observed when hydrogenation takes place in tertiary carbon atoms, showing that the frequencies at which these IR bands appear are a consequence of their position and chemical environment within the molecule