{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T08:11:15Z","timestamp":1789632675108,"version":"build-2803163510"},"reference-count":47,"publisher":"AIP Publishing","issue":"22","content-domain":{"domain":["pubs.aip.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2013,12,14]]},"abstract":"<jats:p>The rotational spectrum of pyridazine (o-C4H4N2), the ortho disubstituted nitrogen analog of benzene, has been measured and analyzed in the gas phase. For the ground vibrational state of the normal isotopolog, over 2000 individual rotational transitions have been identified between 238 and 360\u2009GHz and have been fit to 13 parameters of a 6th-order centrifugal distortion Hamiltonian. All transitions in this frequency region can now be predicted from this model to near experimental accuracy, i.e., well enough for the purpose of any future radio-astronomical search for this species. Three isotopologs, [3-13C]-C4H4N2, [4-13C]-C4H4N2, and [1-15N]-C4H4N2, have been detected in natural abundance, and several hundred lines have been measured for each of these species and fit to 6th-order Hamiltonians. Ten additional isotopologs were synthesized with enhanced deuterium substitution and analyzed to allow for a complete structure determination. The equilibrium structure (Re) of pyridazine was obtained by correcting the experimental rotational constants for the effects of vibration-rotation coupling using interaction constants predicted from CCSD(T) calculations with an ANO0 basis set and further correcting for the effect of electron mass. The final Re structural parameters are determined with excellent accuracy, as evidenced by their ability to predict 28 independent moments of inertia (Ia and Ib for 14 isotopologs) very well from 9 structural parameters. The rotational spectra of the six lowest-energy fundamental vibrational satellites of the main isotopolog have been detected. The rotational spectra of the five lowest-energy vibrational satellites have been assigned and fit to yield accurate rotational and distortion constants, while the fit and assignment for the sixth is less complete. The resultant vibration-rotation interaction (\u03b1) constants are found to be in excellent agreement with ones predicted from coupled-cluster calculations, which proved to be the key to unambiguous assignment of the satellite spectra to specific vibration modes.<\/jats:p>","DOI":"10.1063\/1.4832899","type":"journal-article","created":{"date-parts":[[2013,12,11]],"date-time":"2013-12-11T00:34:43Z","timestamp":1386722083000},"update-policy":"https:\/\/doi.org\/10.1063\/aip-crossmark-policy-page","source":"Crossref","is-referenced-by-count":53,"title":["Rotational spectroscopy of pyridazine and its isotopologs from 235\u2013360\u2009GHz: Equilibrium structure and vibrational satellites"],"prefix":"10.1063","volume":"139","author":[{"given":"Brian J.","family":"Esselman","sequence":"first","affiliation":[{"name":"University of Wisconsin\u2013Madison 1 Department of Chemistry, , Madison, Wisconsin 53706, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Brent K.","family":"Amberger","sequence":"additional","affiliation":[{"name":"University of Wisconsin\u2013Madison 1 Department of Chemistry, , Madison, Wisconsin 53706, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joshua D.","family":"Shutter","sequence":"additional","affiliation":[{"name":"University of Wisconsin\u2013Madison 1 Department of Chemistry, , Madison, Wisconsin 53706, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mitchell A.","family":"Daane","sequence":"additional","affiliation":[{"name":"University of Wisconsin\u2013Madison 1 Department of Chemistry, , Madison, Wisconsin 53706, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John F.","family":"Stanton","sequence":"additional","affiliation":[{"name":"The University of Texas\u2013Austin 2 Institute for Theoretical Chemistry, Departments of Chemistry and Biochemistry, , Austin, Texas 78712, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R. Claude","family":"Woods","sequence":"additional","affiliation":[{"name":"University of Wisconsin\u2013Madison 1 Department of Chemistry, , Madison, Wisconsin 53706, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert J.","family":"McMahon","sequence":"additional","affiliation":[{"name":"University of Wisconsin\u2013Madison 1 Department of Chemistry, , Madison, Wisconsin 53706, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"317","published-online":{"date-parts":[[2013,12,10]]},"reference":[{"key":"2023062523403882500_c1","doi-asserted-by":"publisher","first-page":"427","DOI":"10.1051\/eas\/1146044","article-title":"PAHs and the chemistry of the ISM","volume":"46","year":"2011","journal-title":"Eur. Astron. Soc. Publ. 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Theoretical predictions of the vibration-rotation interaction at various levels of theory. A full list of measured and fit lines for all species in the ASFIT output format."}],"container-title":["The Journal of Chemical Physics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.aip.org\/aip\/jcp\/article-pdf\/doi\/10.1063\/1.4832899\/13322917\/224304_1_online.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.aip.org\/aip\/jcp\/article-pdf\/doi\/10.1063\/1.4832899\/13322917\/224304_1_online.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,6,25]],"date-time":"2023-06-25T23:40:45Z","timestamp":1687736445000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.aip.org\/jcp\/article\/139\/22\/224304\/193370\/Rotational-spectroscopy-of-pyridazine-and-its"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,12,10]]},"references-count":47,"journal-issue":{"issue":"22","published-print":{"date-parts":[[2013,12,14]]}},"URL":"https:\/\/doi.org\/10.1063\/1.4832899","relation":{},"ISSN":["0021-9606","1089-7690"],"issn-type":[{"value":"0021-9606","type":"print"},{"value":"1089-7690","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2013,12,14]]},"published":{"date-parts":[[2013,12,10]]},"article-number":"224304"}}