Hexanitrogen (N6): A Synthetic Leap Towards Neutral Nitrogen Allotropes

Hexanitrogen (N6): A Synthetic Leap Towards Neutral Nitrogen Allotropes | 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 Physical Sciences - Article Hexanitrogen (N6): A Synthetic Leap Towards Neutral Nitrogen Allotropes Peter Schreiner, Weiyu Qian, Artur Mardyukov This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5112084/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 11 Jun, 2025 Read the published version in Nature → Version 1 posted You are reading this latest preprint version Abstract As the availability of renewable energy varies drastically over space and time, energy storage is a prime challenge for humankind. Current strategies include battery systems or high-energy molecules including hydrogen or ammonia for chemical energy storage. Compounds consisting only of the element nitrogen (polynitrogens or nitrogen allotropes), are deemed the cleanest and ideal energy storage materials due to their immense energy content (about five times higher than hydrogen) and because they release only harmless nitrogen (N₂) upon decomposition1. However, their extreme instability poses a significant synthetic challenge and no neutral molecular nitrogen allotrope beyond N2 has been isolated2,3. Here, we present the room temperature preparation of molecular N6 (hexanitrogen) through the gas-phase reaction of chlorine or bromine with silver azide, followed by trapping in argon matrices at 10 K. We also prepared neat N6 as a film at liquid nitrogen temperature (77 K), indicating its unexpectedly high stability (at a temperature that can be handled well) and the scalability of the synthesis. Infrared and ultraviolet spectroscopy, heavy isotope 15N labelling experiments, and ab initio computations firmly support our findings. The preparation of a metastable nitrogen allotrope beyond N₂ opens new vistas for the development of highly sought-after high-energy materials. Physical sciences/Chemistry/Inorganic chemistry/Chemical bonding Physical sciences/Chemistry/Chemical synthesis Physical sciences/Chemistry/Materials chemistry Full Text Additional Declarations There is NO Competing Interest. Supplementary Files N6SISchreiner.pdf Supplementary Information Cite Share Download PDF Status: Published Journal Publication published 11 Jun, 2025 Read the published version in Nature → 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. 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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-5112084","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":359469008,"identity":"ad5c1b50-9894-43cd-ac0e-1e7bd2024be4","order_by":0,"name":"Peter Schreiner","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2UlEQVRIiWNgGAWjYHACxgcMDBIMDMww/gHCWpgNSNbCJoHKJ6TFXPr4s2reHRYM8u7Mhz/+qLjDwHe8Ab8Wy74cs9u8ZyQYDA+zpUnznHnGIHmGgDUGZ3jYbvO2SdRvbOYxY2ZsO8xgcCOBkBb2Z8VALQyGzfyfP/78B9Ry/wEhLQxmzCAt8sw8DBK8DSBb8OtgsOzhMZacC9RiwMxmJs1z7DCP5BkCDjPnYX/44W1bHYN8/+HHH3/UHJbjO36AgMPgDKhCHgLOQtIi30BQ7SgYBaNgFIxUAABBTz4Co9jxFAAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-3608-5515","institution":"Justus Liebig University","correspondingAuthor":true,"prefix":"","firstName":"Peter","middleName":"","lastName":"Schreiner","suffix":""},{"id":359469009,"identity":"387c16ba-fb03-41e9-bfd5-c849623c1e7d","order_by":1,"name":"Weiyu Qian","email":"","orcid":"https://orcid.org/0000-0003-3275-1063","institution":"Institut of Organic Chemistry, Justus-Liebig-University","correspondingAuthor":false,"prefix":"","firstName":"Weiyu","middleName":"","lastName":"Qian","suffix":""},{"id":359469010,"identity":"2f32e897-8266-4bb1-9f1a-c91b80a7133d","order_by":2,"name":"Artur Mardyukov","email":"","orcid":"","institution":"Institut of Organic Chemistry, Justus-Liebig-University","correspondingAuthor":false,"prefix":"","firstName":"Artur","middleName":"","lastName":"Mardyukov","suffix":""}],"badges":[],"createdAt":"2024-09-18 18:46:31","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5112084/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5112084/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41586-025-09032-9","type":"published","date":"2025-06-11T04:00:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":84452401,"identity":"5b63ed86-aa8e-4356-bfda-61df4cb52cce","added_by":"auto","created_at":"2025-06-12 07:06:33","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1434964,"visible":true,"origin":"","legend":"Article File","description":"","filename":"N6Schreiner.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5112084/v1_covered_720358b5-664b-482c-9ea5-c580f4126ee5.pdf"},{"id":65560498,"identity":"d2327119-5034-4164-97f8-6252cb8d009d","added_by":"auto","created_at":"2024-09-30 03:44:00","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":2306448,"visible":true,"origin":"","legend":"Supplementary Information","description":"","filename":"N6SISchreiner.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5112084/v1/1b454d8f0a0b895db28a11b2.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Hexanitrogen (N6): A Synthetic Leap Towards Neutral Nitrogen Allotropes","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-5112084/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5112084/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"As the availability of renewable energy varies drastically over space and time, energy storage is a prime challenge for humankind. 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