{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,24]],"date-time":"2025-11-24T07:16:52Z","timestamp":1763968612380,"version":"build-2065373602"},"reference-count":40,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,3,27]],"date-time":"2025-03-27T00:00:00Z","timestamp":1743033600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Brazilian agencies Coordena\u00e7\u00e3o de Aperfei\u00e7oamento de Pessoal de N\u00edvel Superior (CAPES)","award":["226716 (ELISA)","UID\/00068"],"award-info":[{"award-number":["226716 (ELISA)","UID\/00068"]}]},{"name":"Conselho Nacional de Desenvolvimento Cient\u00edfico e Tecnol\u00f3gico (CNPq)","award":["226716 (ELISA)","UID\/00068"],"award-info":[{"award-number":["226716 (ELISA)","UID\/00068"]}]},{"name":"European Community\u2019s Seventh Framework Program (FP7\/2007-2013)","award":["226716 (ELISA)","UID\/00068"],"award-info":[{"award-number":["226716 (ELISA)","UID\/00068"]}]},{"name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia (FCT) CEFITEC","award":["226716 (ELISA)","UID\/00068"],"award-info":[{"award-number":["226716 (ELISA)","UID\/00068"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>In this work, we provide results from a joint experimental and theoretical study of the vibronic features of cyclohexane (C6H12) in the photon energy range of 6.8\u201310.8 eV (182\u2013115 nm). The high-resolution vacuum ultraviolet (VUV) photoabsorption measurements, together with quantum chemical calculations at the time-dependent density functional theory (TDDFT) level, have helped to assign the major electronic excitations to mixed valence\u2013Rydberg and Rydberg transitions. The C6H12 photoabsorption spectrum shows fine structure which has been assigned to CH2 scissoring, v3\u2032a1g, CH2 rocking, v4\u2032a1g, C\u2013C stretching, v5\u2032a1g, and CCC bending\/CC torsion, v24\u2032eg, modes. Molecular structure calculations at the DFT level for the neutral and cationic electronic ground-states have shown the relevant structural changes that are operative in the higher-lying electronic states. Photolysis lifetimes in the Earth\u2019s atmosphere are shown to be irrelevant, while the main atmospheric sink mechanism is the reaction with the \u2022OH radical. Potential energy curves have been obtained at the TDDFT level of theory, showing the relevance of interchange character mainly involving the CH2 scissoring, v3\u2032a1g, and CH2 rocking, v4\u2032a1g, modes, while Jahn\u2013Teller distortion yields weak vibronic coupling involving the non-totally symmetric CCC bending\/CC torsion, v24\u2032eg, mode.<\/jats:p>","DOI":"10.3390\/molecules30071493","type":"journal-article","created":{"date-parts":[[2025,3,28]],"date-time":"2025-03-28T03:35:28Z","timestamp":1743132928000},"page":"1493","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Cyclohexane Vibronic States: A Combined VUV Spectroscopy and Theoretical Study"],"prefix":"10.3390","volume":"30","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-6156-8355","authenticated-orcid":false,"given":"Edvaldo","family":"Bandeira","sequence":"first","affiliation":[{"name":"Departamento de F\u00edsica, Universidade Federal do Paran\u00e1, Caixa Postal 19044, Curitiba 81531-980, PR, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7989-1878","authenticated-orcid":false,"given":"Alessandra S.","family":"Barbosa","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica, Universidade Federal do Paran\u00e1, Caixa Postal 19044, Curitiba 81531-980, PR, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4081-6405","authenticated-orcid":false,"given":"Nykola C.","family":"Jones","sequence":"additional","affiliation":[{"name":"ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8018-5433","authenticated-orcid":false,"given":"S\u00f8ren V.","family":"Hoffmann","sequence":"additional","affiliation":[{"name":"ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9322-1360","authenticated-orcid":false,"given":"M\u00e1rcio H. F.","family":"Bettega","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica, Universidade Federal do Paran\u00e1, Caixa Postal 19044, Curitiba 81531-980, PR, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2696-1152","authenticated-orcid":false,"given":"Paulo","family":"Lim\u00e3o-Vieira","sequence":"additional","affiliation":[{"name":"Departamento de F\u00edsica, Universidade Federal do Paran\u00e1, Caixa Postal 19044, Curitiba 81531-980, PR, Brazil"},{"name":"Atomic and Molecular Collisions Laboratory, Centre of Physics and Technological Research (CEFITEC), Department of Physics, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"905","DOI":"10.1016\/1352-2310(94)00287-U","article-title":"Modeling the Atmospheric Concentrations of Individual Volatile Organic Compounds","volume":"29","author":"Harley","year":"1995","journal-title":"Atmos. 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