A neutral cyclic aluminium (I) trimer

A neutral cyclic aluminium (I) trimer | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article A neutral cyclic aluminium (I) trimer Clare Bakewell, Imogen Squire, Matthew de Vere-Tucker, Michelangelo Tritto, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7047009/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 30 Jan, 2026 Read the published version in Nature Communications → Version 1 posted You are reading this latest preprint version Abstract As part of the quest to develop metal-based redox chemistry beyond the d-block, low oxidation state aluminium complexes have gained wide recognition as discrete and versatile 2-electron reductants. Despite reports of monomeric, dimeric and tetrameric neutral structures, as well as a range of charged aluminyl compounds, neutral trimeric structures have remained notably absent. Furthermore, trimeric nuclearity has previously not been considered when investigating reaction mechanisms. Here, we report two unprecedented neutral AlI trimers, cyclotrialumanes. The molecules have been extensively characterised using both experimental and computational techniques, with the Al–Al bonds described as principally covalent in nature and the trimeric structure proven to be retained in solution. The cyclotrialumanes are highly reactive, activating a range of small molecules and unsaturated substrates (e.g. H2, alkyne, benzene). Most significantly, through a series of extraordinary reactions with ethylene, the cyclotrialumanes are shown to react directly as trimers, forming unparallelled 5- and 7-membered Al–C ring systems. Physical sciences/Chemistry/Chemical synthesis/Synthetic chemistry methodology Physical sciences/Chemistry/Coordination chemistry/Organometallic chemistry/Chemical bonding Physical sciences/Chemistry/Theoretical chemistry/Density functional theory Physical sciences/Chemistry/Inorganic chemistry/Organometallic chemistry/Chemical bonding Full Text Additional Declarations There is NO Competing Interest. Supplementary Files DFTcoordinates.txt Dataset 1 BakewellSI.pdf Supporting information Cite Share Download PDF Status: Published Journal Publication published 30 Jan, 2026 Read the published version in Nature Communications → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7047009","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":489228903,"identity":"51eb73db-a732-42b6-a8d8-6d310fa6e879","order_by":0,"name":"Clare 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Despite reports of monomeric, dimeric and tetrameric neutral structures, as well as a range of charged aluminyl compounds, neutral trimeric structures have remained notably absent. Furthermore, trimeric nuclearity has previously not been considered when investigating reaction mechanisms. \r\n\r\nHere, we report two unprecedented neutral AlI trimers, cyclotrialumanes. The molecules have been extensively characterised using both experimental and computational techniques, with the Al–Al bonds described as principally covalent in nature and the trimeric structure proven to be retained in solution. The cyclotrialumanes are highly reactive, activating a range of small molecules and unsaturated substrates (e.g. H2, alkyne, benzene). 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