J/ApJ/662/1309 Rotational spectra of small PAHs (Thorwirth+, 2007)
Rotational spectra of small PAHs: acenaphthene, acenaphthylene, azulene,
and fluorene.
Thorwirth S., Theule P., Gottlieb C.A., McCarthy M.C., Thaddeus P.
<Astrophys. J., 662, 1309-1314 (2007)>
=2007ApJ...662.1309T 2007ApJ...662.1309T
ADC_Keywords: Atomic physics
Keywords: astrochemistry - ISM: molecules - molecular data
Abstract:
Pure rotational spectra of four small polycyclic aromatic hydrocarbons
have been observed by Fourier transform microwave spectroscopy of
a molecular beam in the frequency range from 7 to 37GHz. Initial
searches for acenaphthene (C12H10), acenaphthylene (C12H8), and
fluorene (C13H10) were guided by quantum chemical calculations
performed at the B3LYP/cc-pVTZ level of theory. All three molecules
exhibit b-type rotational spectra and are calculated to be moderately
polar, with dipole moments of 0.3-0.9D. Close agreement (to better
than 1%) between the calculated equilibrium and experimentally derived
ground-state rotational constants is achieved. Selected transitions of
acenaphthene and fluorene have also been measured in the 3mm region
by conventional free-space absorption spectroscopy, as have
transitions of the previously studied azulene (C10H8). The data
presented here facilitate deep radio astronomical searches with large
radio telescopes.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 46 115 Experimental rotational transition frequencies
of Azulene (C10H8)
table3.dat 46 227 Selected experimental rotational transition
frequencies of Acenaphthene (C12H10)
table6.dat 46 57 Selected experimental rotational transition
frequencies of Acenaphthylene (C12H8)
table8.dat 46 114 Selected experimental rotational transition
frequencies of Fluorene (C13H10)
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Byte-by-byte Description of file: table*.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- J' The upper J quantum number
5- 6 I2 --- Ka' The upper Ka quantum number
8- 10 I3 --- Kc' The upper Kc quantum number
12- 14 I3 --- J" The lower J quantum number
16- 17 I2 --- Ka" The lower Ka quantum number
19- 21 I3 --- Kc" The lower Kc quantum number
23- 32 F10.4 MHz Freq The experimental frequency of the transition
34- 40 F7.4 MHz O-C The observed minus calculated value
42- 46 F5.3 MHz e_Freq Estimated experimental uncertainty in Freq
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 22-May-2009