skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: POLYCYCLIC AROMATIC HYDROCARBONS WITH ARMCHAIR EDGES AND THE 12.7 μm BAND

Abstract

In this Letter, we report the results of density functional theory calculations on medium-sized neutral polycyclic aromatic hydrocarbon (PAH) molecules with armchair edges. These PAH molecules possess strong C-H stretching and bending modes around 3 μm and in the fingerprint region (10-15 μm), and also strong ring deformation modes around 12.7 μm. Perusal of the entries in the NASA Ames PAHs Database shows that ring deformation modes of PAHs are common, although generally weak. Therefore, we propose that armchair PAHs with N{sub C} > 65 are responsible for the 12.7 μm aromatic infrared band in H II regions and discuss the astrophysical implications in the context of the PAH life cycle.

Authors:
Publication Date:
OSTI Identifier:
22365365
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 791; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; DENSITY FUNCTIONAL METHOD; H2 REGIONS; INFRARED SPECTRA; LIFE CYCLE; MOLECULES; POLYCYCLIC AROMATIC HYDROCARBONS

Citation Formats

Candian, A., Tielens, A. G. G. M., and Sarre, P. J., E-mail: candian@strw.leidenuniv.nl. POLYCYCLIC AROMATIC HYDROCARBONS WITH ARMCHAIR EDGES AND THE 12.7 μm BAND. United States: N. p., 2014. Web. doi:10.1088/2041-8205/791/1/L10.
Candian, A., Tielens, A. G. G. M., & Sarre, P. J., E-mail: candian@strw.leidenuniv.nl. POLYCYCLIC AROMATIC HYDROCARBONS WITH ARMCHAIR EDGES AND THE 12.7 μm BAND. United States. https://doi.org/10.1088/2041-8205/791/1/L10
Candian, A., Tielens, A. G. G. M., and Sarre, P. J., E-mail: candian@strw.leidenuniv.nl. 2014. "POLYCYCLIC AROMATIC HYDROCARBONS WITH ARMCHAIR EDGES AND THE 12.7 μm BAND". United States. https://doi.org/10.1088/2041-8205/791/1/L10.
@article{osti_22365365,
title = {POLYCYCLIC AROMATIC HYDROCARBONS WITH ARMCHAIR EDGES AND THE 12.7 μm BAND},
author = {Candian, A. and Tielens, A. G. G. M. and Sarre, P. J., E-mail: candian@strw.leidenuniv.nl},
abstractNote = {In this Letter, we report the results of density functional theory calculations on medium-sized neutral polycyclic aromatic hydrocarbon (PAH) molecules with armchair edges. These PAH molecules possess strong C-H stretching and bending modes around 3 μm and in the fingerprint region (10-15 μm), and also strong ring deformation modes around 12.7 μm. Perusal of the entries in the NASA Ames PAHs Database shows that ring deformation modes of PAHs are common, although generally weak. Therefore, we propose that armchair PAHs with N{sub C} > 65 are responsible for the 12.7 μm aromatic infrared band in H II regions and discuss the astrophysical implications in the context of the PAH life cycle.},
doi = {10.1088/2041-8205/791/1/L10},
url = {https://www.osti.gov/biblio/22365365}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 791,
place = {United States},
year = {Sun Aug 10 00:00:00 EDT 2014},
month = {Sun Aug 10 00:00:00 EDT 2014}
}