{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T17:02:25Z","timestamp":1790096545487,"version":"4.0.1"},"reference-count":35,"publisher":"American Chemical Society (ACS)","issue":"37","license":[{"start":{"date-parts":[[2026,9,4]],"date-time":"2026-09-04T00:00:00Z","timestamp":1788480000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007620","name":"Department of Education of Liaoning Province","doi-asserted-by":"publisher","award":["JYTMS20231431"],"award-info":[{"award-number":["JYTMS20231431"]}],"id":[{"id":"10.13039\/501100007620","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007620","name":"Department of Education of Liaoning Province","doi-asserted-by":"publisher","award":["JYTMS20231432"],"award-info":[{"award-number":["JYTMS20231432"]}],"id":[{"id":"10.13039\/501100007620","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,22]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Cyclo[6]carbon (C6), the smallest even-membered cyclocarbon, provides a stringent platform for examining how a highly strained sp-hybridized carbon ring responds to changes in electronic state. Here, we investigate the structural, electronic, magnetic-response, excited-state, and stability\/reactivity features of C6 using density functional theory, time-dependent density functional theory, ab initio molecular dynamics, and a CASSCF(12,12) occupation-number analysis. The optimized S0 structure is strictly planar and shows pronounced bond-angle alternation together with nearly uniform C\u2013C bond lengths, indicating that its bonding cannot be described by a simple localized alternating-bond picture. Real-space descriptors, including IRI-\u03c0 and ELF-\u03c0, outline a continuous dual-\u03c0 delocalized framework in S0 and provide the electronic reference for analyzing state-dependent magnetic responses. Magnetic-response analyses based on ACID, ICSSzz, and NICSzz further show that the selected high-spin quintet Q1 state undergoes a pronounced reversal from the diatropic response of S0 to a paratropic response. A CASSCF(12,12) occupation-number analysis supports a predominantly closed-shell description of S0 C6, with no indication of pronounced open-shell multireference character, thereby supporting the qualitative interpretation of the DFT-based descriptors. Density-of-states and representative excited-state analyses further indicate that changes in electronic-state occupation redistribute electron density within the \u03c0in and \u03c0out manifolds, providing additional electronic-structure context for state-dependent changes within the dual-\u03c0 framework. AIMD simulations indicate that the S0 ring framework is kinetically stable at low temperature but becomes increasingly flexible at elevated temperature, while ESP and ALIE analyses identify the C\u2013C framework as the main reactive region. These results reveal a pronounced aromaticity reversal in the high-spin Q1 state and highlight the spin-state-dependent magnetic response of the dual-\u03c0 framework in C6.<\/jats:p>","DOI":"10.1021\/acsomega.6c06543","type":"journal-article","created":{"date-parts":[[2026,9,4]],"date-time":"2026-09-04T21:02:03Z","timestamp":1788555723000},"page":"56170-56179","source":"Crossref","is-referenced-by-count":0,"title":["High-Spin-State-Induced\nAromaticity Reversal in Cyclo[6]carbon"],"prefix":"10.1021","volume":"11","author":[{"given":"Gang","family":"Zhang","sequence":"first","affiliation":[{"name":"Liaoning Petrochemical University , , ,","place":["Fushun, China, 113001"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiayuan","family":"Cui","sequence":"additional","affiliation":[{"name":"Liaoning Petrochemical University , , ,","place":["Fushun, China, 113001"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ying","family":"Jin","sequence":"additional","affiliation":[{"name":"Liaoning Petrochemical University , , ,","place":["Fushun, China, 113001"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi","family":"Zou","sequence":"additional","affiliation":[{"name":"Liaoning Petrochemical University , , ,","place":["Fushun, China, 113001"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4221-2629","authenticated-orcid":true,"given":"Jingang","family":"Wang","sequence":"additional","affiliation":[{"name":"Liaoning Petrochemical University , , ,","place":["Fushun, China, 113001"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,9,4]]},"reference":[{"key":"2026092211025784200_cit1","doi-asserted-by":"publisher","first-page":"468","DOI":"10.1016\/j.carbon.2020.04.099","article-title":"An Sp-Hybridized All-Carboatomic Ring, Cyclo [18] Carbon:\nBonding Character, Electron Delocalization, and Aromaticity","volume":"165","author":"Liu","year":"2020","journal-title":"Carbon"},{"issue":"8","key":"2026092211025784200_cit2","doi-asserted-by":"publisher","DOI":"10.1002\/tcr.202400055","article-title":"Chemistry\nof Cyclo[18]Carbon (C18): A Review","volume":"24","author":"Pooja","year":"2024","journal-title":"Chem. Rec."},{"issue":"22","key":"2026092211025784200_cit3","doi-asserted-by":"publisher","first-page":"10129","DOI":"10.1021\/ja00101a035","article-title":"Double Aromaticity in the 3, 5-Dehydrophenyl Cation and in Cyclo\n[6] Carbon","volume":"116","author":"Schleyer","year":"1994","journal-title":"J. Am. Chem. Soc."},{"issue":"6","key":"2026092211025784200_cit4","doi-asserted-by":"publisher","first-page":"585","DOI":"10.1038\/s41557-022-00961-w","article-title":"Aromaticity\nRules","volume":"14","author":"Sola","year":"2022","journal-title":"Nat. Chem."},{"issue":"16","key":"2026092211025784200_cit5","doi-asserted-by":"publisher","first-page":"2445","DOI":"10.1021\/acs.jpca.1c08507","article-title":"Odd-Number Cyclo[n]Carbons Sustaining Alternating Aromaticity","volume":"126","author":"Baryshnikov","year":"2022","journal-title":"J. Phys. Chem. A"},{"issue":"6459","key":"2026092211025784200_cit6","doi-asserted-by":"publisher","first-page":"1299","DOI":"10.1126\/science.aay1914","article-title":"An Sp-Hybridized\nMolecular Carbon Allotrope, Cyclo[18]Carbon","volume":"365","author":"Kaiser","year":"2019","journal-title":"Science"},{"issue":"30","key":"2026092211025784200_cit7","doi-asserted-by":"publisher","first-page":"12921","DOI":"10.1021\/jacs.0c05033","article-title":"Synthesis\nof Cyclo[18]Carbon via Debromination of C18 Br6","volume":"142","author":"Scriven","year":"2020","journal-title":"J. Am. Chem. Soc."},{"issue":"7989","key":"2026092211025784200_cit8","doi-asserted-by":"publisher","first-page":"977","DOI":"10.1038\/s41586-023-06566-8","article-title":"On-Surface\nSynthesis of a Doubly Anti-Aromatic Carbon Allotrope","volume":"623","author":"Gao","year":"2023","journal-title":"Nature"},{"issue":"7989","key":"2026092211025784200_cit9","doi-asserted-by":"publisher","first-page":"972","DOI":"10.1038\/s41586-023-06741-x","article-title":"On-Surface Synthesis of Aromatic Cyclo [10] Carbon and Cyclo [14]\nCarbon","volume":"623","author":"Sun","year":"2023","journal-title":"Nature"},{"issue":"1","key":"2026092211025784200_cit10","doi-asserted-by":"publisher","first-page":"7649","DOI":"10.1038\/s41467-024-52115-w","article-title":"On-Surface Synthesis\nand Characterization of Anti-Aromatic\nCyclo [12] Carbon and Cyclo [20] Carbon","volume":"15","author":"Sun","year":"2024","journal-title":"Nat.\nCommun."},{"issue":"8","key":"2026092211025784200_cit11","doi-asserted-by":"publisher","first-page":"940","DOI":"10.1038\/s44160-025-00784-w","article-title":"On-Surface Synthesis and Characterization\nof Linear and Cyclic C6","volume":"4","author":"Sun","year":"2025","journal-title":"Nat. Synth."},{"issue":"8","key":"2026092211025784200_cit12","doi-asserted-by":"publisher","first-page":"4823","DOI":"10.1039\/D0CP00167H","article-title":"Potential Molecular Semiconductor\nDevices: Cyclo-C n (N= 10 and 14) with Higher Stabilities and Aromaticities\nthan Acknowledged Cyclo-C 18","volume":"22","author":"Li","year":"2020","journal-title":"Phys. Chem. Chem.\nPhys."},{"issue":"51","key":"2026092211025784200_cit13","doi-asserted-by":"publisher","first-page":"10849","DOI":"10.1021\/acs.jpca.0c09692","article-title":"Aromaticity of Even-Number Cyclo[n]Carbons (n = 6\u2013100)","volume":"124","author":"Baryshnikov","year":"2020","journal-title":"J. Phys. Chem. 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Chem.\nRes."},{"issue":"20","key":"2026092211025784200_cit17","doi-asserted-by":"publisher","first-page":"14831","DOI":"10.1021\/acs.joc.3c01807","article-title":"Magnetic Antiaromaticity\u2500Paratropicity\u2500Does\nNot Necessarily Imply Instability","volume":"88","author":"Foroutan-Nejad","year":"2023","journal-title":"J. Org. Chem."},{"issue":"3","key":"2026092211025784200_cit18","doi-asserted-by":"publisher","first-page":"715","DOI":"10.1007\/s11224-024-02328-y","article-title":"Aromaticity\n\u2013 a Theoretical Notion","volume":"35","author":"Agranat","year":"2024","journal-title":"Struct. 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Rev."},{"issue":"5","key":"2026092211025784200_cit29","doi-asserted-by":"publisher","first-page":"231","DOI":"10.1002\/cmtd.202100007","article-title":"Interaction Region\nIndicator: A Simple Real Space Function Clearly\nRevealing Both Chemical Bonds and Weak Interactions**","volume":"1","author":"Lu","year":"2021","journal-title":"Chem.: Methods"},{"issue":"9","key":"2026092211025784200_cit30","doi-asserted-by":"publisher","first-page":"5397","DOI":"10.1063\/1.458517","article-title":"A Simple\nMeasure of Electron Localization in Atomic\nand Molecular Systems","volume":"92","author":"Becke","year":"1990","journal-title":"J. Chem. Phys."},{"issue":"26","key":"2026092211025784200_cit31","doi-asserted-by":"publisher","first-page":"6317","DOI":"10.1021\/ja960582d","article-title":"Nucleus-Independent Chemical Shifts: A Simple and Efficient\nAromaticity Probe","volume":"118","author":"Schleyer","year":"1996","journal-title":"J. Am. Chem. Soc."},{"issue":"21","key":"2026092211025784200_cit32","doi-asserted-by":"publisher","first-page":"3120","DOI":"10.1002\/ejoc.201901829","article-title":"NICS \u2013\nPast and Present","volume":"2020","author":"Stanger","year":"2020","journal-title":"Eur. J. Org. Chem."},{"issue":"11","key":"2026092211025784200_cit33","doi-asserted-by":"publisher","first-page":"4009","DOI":"10.1021\/cr0505627","article-title":"Single-Reference Ab Initio Methods for the Calculation\nof Excited States of Large Molecules","volume":"105","author":"Dreuw","year":"2005","journal-title":"Chem.\nRev."},{"issue":"19","key":"2026092211025784200_cit34","doi-asserted-by":"publisher","first-page":"194103","DOI":"10.1063\/5.0007045","article-title":"CP2K: An Electronic\nStructure and Molecular Dynamics Software Package-Quickstep: Efficient\nand Accurate Electronic Structure Calculations","volume":"152","author":"Ku\u0308hne","year":"2020","journal-title":"J. Chem. Phys."},{"issue":"1","key":"2026092211025784200_cit35","doi-asserted-by":"publisher","first-page":"33","DOI":"10.1016\/0263-7855(96)00018-5","article-title":"VMD: Visual\nMolecular Dynamics","volume":"14","author":"Humphrey","year":"1996","journal-title":"J. Mol. Graphics"}],"container-title":["ACS Omega"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/acsomega.6c06543","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/acsodf\/article-pdf\/11\/37\/56170\/68393685\/acsomega.6c06543.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/acsodf\/article-pdf\/11\/37\/56170\/68393685\/acsomega.6c06543.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T16:04:10Z","timestamp":1790093050000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/acsodf\/article\/11\/37\/56170\/5421758\/High-Spin-State-Induced-Aromaticity-Reversal-in"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,4]]},"references-count":35,"journal-issue":{"issue":"37","published-online":{"date-parts":[[2026,9,4]]},"published-print":{"date-parts":[[2026,9,22]]}},"URL":"https:\/\/doi.org\/10.1021\/acsomega.6c06543","relation":{},"ISSN":["2470-1343"],"issn-type":[{"value":"2470-1343","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,4]]}}}