{
  "abstract": "Partial semi-experimental equilibrium (reSE) and substitution (rsSE) structures of cyclobutenone (c-C4H4O, Cs, μa = 3.4 D) have been determined for the first time via rotational spectroscopy. The rotational spectrum of this reactive species, which contains a highly strained four-membered ring, has been measured from 9 to 735 GHz. Over 3800 transitions for the ground vibrational state of the normal isotopologue of cyclobutenone were measured, assigned, and least-squares fit to sextic distorted-rotor A- and S-reduced Hamiltonians in the Ir representation, providing a complete set of quartic and sextic centrifugal distortion parameters. Rotational transitions for each of the singly substituted heavy-atom isotopologues were measured at natural abundance. Rotational constants (B0) for the six isotopologues were converted to equilibrium values (Be) using CCSD(T)/cc-pCVTZ vibration-rotation interaction and electron-mass corrections, enabling the determination of partial reSE and rsSE structures that define all of the heavy-atom parameters of cyclobutenone. The two different sets of semi-experimental structural parameters (reSE and rsSE) are compared to the \"best theoretical estimate\" (BTE re) values, which are derived from the CCSD(T)/cc-pCV5Z re structure with additional corrections addressing finite basis set, higher-level electron correlation, and relativistic effects, as well as incorporating the diagonal Born-Oppenheimer correction. Additionally, transitions of the four lowest-energy vibrationally excited states have been assigned, measured, and least-squares fit to A-reduced, sextic centrifugally distorted-rotor Hamiltonians in the Ir representation. While ν21 was well-modeled using a single-state Hamiltonian, 2ν21, ν14, and ν20 form an anharmonic- and Coriolis-coupled triad and were treated by a three-state Hamiltonian model.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin53706, United States.",
    "Department of Chemistry and Biochemistry, Kent State University, Kent, Ohio44240, United States.",
    "Quantum Theory Project, Departments of Physics and Chemistry, University of Florida, Gainesville, Florida32611, United States."
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Brian J Esselman",
      "orcid": "0000-0002-9385-8078"
    },
    {
      "affs": [
        1
      ],
      "name": "Michael J Carrillo",
      "orcid": "0000-0001-6060-4664"
    },
    {
      "affs": [
        0
      ],
      "name": "Madeleine G Atwood",
      "orcid": "0000-0002-5319-8845"
    },
    {
      "affs": [
        2
      ],
      "name": "Nitai P Sahoo"
    },
    {
      "affs": [
        1
      ],
      "name": "Zoe K Deems"
    },
    {
      "affs": [
        1
      ],
      "name": "Michael J Tubergen",
      "orcid": "0000-0002-5646-0300"
    },
    {
      "affs": [
        0
      ],
      "name": "Maria A Zdanovskaia",
      "orcid": "0000-0001-5167-8573"
    },
    {
      "affs": [
        0
      ],
      "name": "R Claude Woods",
      "orcid": "0000-0003-0865-4693"
    },
    {
      "affs": [
        0
      ],
      "name": "Robert J McMahon",
      "orcid": "0000-0003-1377-5107"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1qwaq2mgtrekq.bib",
  "cited_by": 0,
  "doi": "10.1021/acs.jpca.6c04937",
  "fulltext_url": "https://europepmc.org/articles/PMC13656784",
  "id": "1qwaq2mgtrekq",
  "issns": [
    "1089-5639",
    "1520-5215"
  ],
  "landing_url": "https://europepmc.org/article/MED/42917613",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "1607|Molecular Spectroscopy and Structure"
    ]
  ],
  "openalex": "W7214597016",
  "pdf_url": "https://europepmc.org/articles/PMC13656784?pdf=render",
  "pmcid": "PMC13656784",
  "pmid": "42917613",
  "published": "2026-10-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/1qwaq2mgtrekq.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:36Z",
      "native_id": "MED:42917613",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42917613"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1607|Molecular Spectroscopy and Structure",
      "subfield": "physical"
    }
  ],
  "title": "Rotational Spectroscopy and Partial Semi-Experimental Equilibrium (reSE) and Substitution (rsSE) Structures of Cyclobutenone (c-C4H4O).",
  "title_text": "Rotational Spectroscopy and Partial Semi-Experimental Equilibrium (reSE) and Substitution (rsSE) Structures of Cyclobutenone (c-C4H4O).",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:20:36Z",
  "url": "https://research.draconitic.com/paper/1qwaq2mgtrekq",
  "venue": "The journal of physical chemistry. A",
  "versions": []
}