J/ApJ/662/1309ivo://CDS.VizieR/J/ApJ/662/1309doi:10.26093/cds/vizier.16621309CDSThorwirth S.Theule P.Gottlieb C.A.McCarthy M.C.Thaddeus P.2017-06-01T08:52:35Z2009-07-09T04:27:14ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.fratomic-physicsPure 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 (C_12_H_10_), acenaphthylene (C_12_H_8_), and fluorene (C_13_H_10_) 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 (C_10_H_8_). The data presented here facilitate deep radio astronomical searches with large radio telescopes.2007ApJ...662.1309Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/662/1309CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/662/1309https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/662/1309http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/662/1309https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/662/1309https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/662/1309http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/662/1309GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/662/1309/new_nameExperimental rotational transition frequencies of 4 PAHsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMolSimbad column added by the CDSmeta.id;meta.datasetintnullableJ'The upper J quantum numberinstr.det.qe;stat.maxintKa'The upper Ka quantum numberphys.atmol.qn;stat.maxintKc'The upper Kc quantum numberphys.atmol.qn;stat.maxintJ"The lower J quantum numberinstr.det.qe;stat.minintKa"The lower Ka quantum numberphys.atmol.qn;stat.minintKc"The lower Kc quantum numberphys.atmol.qn;stat.minintFreqThe experimental frequency of the transitionMHzem.freq;phys.atmol.transitiondoublee_FreqEstimated experimental uncertainty in FreqMHzstat.errorfloatO-CThe observed minus calculated valueMHzstat.fit.residualfloat