The ‘π-Trap’ as an Unrestricted Crystal Sponge for Inherently Amorphous Cluster Compounds

The ‘π-Trap’ as an Unrestricted Crystal Sponge for Inherently Amorphous Cluster Compounds | 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 The ‘π-Trap’ as an Unrestricted Crystal Sponge for Inherently Amorphous Cluster Compounds Stefanie Dehnen, Yaofeng Wang, Niklas Rinn, Kevin Eberheim, Ferdinand Ziese, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5953585/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 25 Aug, 2025 Read the published version in Nature Communications → Version 1 posted You are reading this latest preprint version Abstract Single crystal diffraction is one of the most common and powerful tools for structural elucidation in science. However, obtaining single crystals of adequate size and quality is not always trivial, with some chemicals inherently resisting all attempts. The ‘crystalline sponge’ method has attracted a lot of attention for crystallizing otherwise intrinsically amorphous compounds inside a metal organic framework (MOF).1,2 However, its application is limited by the size and stability of the pores within the networks. In this study, we propose a novel ‘unrestricted crystalline sponge’ method, which we denominate as the ‘π-trap’. It makes use of π-π interactions between C60 and nm-sized molecules that by themselves do not form crystalline compounds. Using this technique, we successfully crystallized adamantane-like organic-inorganic hybrid clusters, which exhibit extreme nonlinear optical properties only within the amorphous habitus, and resist any attempt for crystallization. As the clusters' low tendency to order in the long range was successfully overcome by the strong C60···cluster interactions in the ‘π-trap’, we were able to precisely determine their molecular structures. As we could show by optical spectroscopy and quantum chemical calculations, both the clusters and C60 behave like being dissolved in the other component, including the formation of cluster pairs previously proposed by theoretical studies and low-angle scattering experiments on amorphous samples. We propose that the described method is applicable to all kinds of amorphous compounds that allow for π-π interactions, without the size restrictions facing the ‘crystalline sponge’ method, especially when considering the usage of larger fullerenes. Physical sciences/Chemistry/Inorganic chemistry/Organometallic chemistry Physical sciences/Chemistry/Inorganic chemistry/Solid-state chemistry Physical sciences/Materials science/Nanoscale materials/Structural properties Physical sciences/Materials science/Techniques and instrumentation/Design, synthesis and processing Physical sciences/Physics/Quantum physics/Theoretical physics π-π interactions unrestricted crystal sponge amorphous compounds cluster molecules C60 Full Text Additional Declarations There is NO Competing Interest. Supplementary Files 1PhSnSC601checkcif.pdf 1-PhSnSC60_1-checkcif.pdf 2PhSnSC601.5checkcif.pdf 2-PhSnSC60_1.5-checkcif.pdf 3PhSnSeC60.pdf 3-PhSnSeC60.pdf PiTrapSISD.pdf Pi-Trap-SI-SD.pdf Cite Share Download PDF Status: Published Journal Publication published 25 Aug, 2025 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-5953585","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":411668943,"identity":"51b3463a-1244-411d-9343-7fb8d690e5ef","order_by":0,"name":"Stefanie 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