Henke Group

Emergent Spin‐Glass Behavior in an Iron(II)‐Based Metal–Organic Framework Glass A one-pot, solvent-free synthesis yields an Fe2+-based metal-organic framework (MOF) glass featuring a continuous random network structure. The material exhibits spin-glass freezing at 14 K, driven b...

Our first step into disordered magnetism is out in Advanced Functional Materials!
We show a Fe²⁺ MOF glass with spin-glass freezing at ~14 K — magnetism driven by topological disorder. Check it out: advanced.onlinelibrary.wiley.com/doi/10.1002/...
Thanks to @dfg.de and TU Dortmund for support.

Emergent Spin‐Glass Behavior in an Iron(II)‐Based Metal–Organic Framework Glass https://advanced.onlinelibrary.wiley.com/doi/10.1002/adfm.202517854?af=R

Organic flux-mediated ligand exchange enables coordination sphere engineering and topological restructuring in metal-organic framework glasses Melt-quenched glasses derived from metal-organic frameworks (MOFs) combine the processability of glasses with the modularity and microporosity of MOFs, yet remain structurally and functionally less di...

Meltable MOFs are unique in many ways. In our new preprint we show that you can let molten MOFs react with an organic ligand and obtain some interesting glasses. 🔍 A highly collaborative effort.
doi.org/10.26434/che...

Mechanochemical Synthesis Enables Melting, Glass Formation and Glass–Ceramic Conversion in a Cadmium-Based Zeolitic Imidazolate Framework http://dx.doi.org/10.1021/jacs.5c02767

Mechanochemical Synthesis Enables Melting, Glass Formation and Glass–Ceramic Conversion in a Cadmium-Based Zeolitic Imidazolate Framework Metal-organic frameworks (MOFs) are versatile materials with tunable properties and broad applications. Here, we report the first cadmium-based zeolitic imidazolate framework (ZIF) glass, prepared by melt-quenching sub-micrometer-sized Cd(im)2 particles (im– = imidazolate) obtained via mechanochemical synthesis. This route increases defect density and reduces crystallite domain size, lowering the melting temperature from 461 °C (for larger solution-synthesized microcrystals) to 455 °C, thereby mitigating thermal decomposition during melting. Crystalline Cd(im)2 adopts a two-fold interpenetrated diamondoid (dia-c) topology, assembled from tetrahedral Cd2+ centers and im– linkers. Rapid cooling of the Cd(im)2 melt yields a monolithic glass with a glass transition temperature (Tg) of 175 °C. Structural analysis confirms that short-range connectivity within individual networks is maintained, whereas interactions between the interpenetrated networks are disrupted in the glass. Upon reheating, partial recrystallization produces a single-component glass–ceramic with enhanced mechanical properties, an unprecedented behavior in melt-quenched ZIF glasses. Investigations of thermal parameters (cooling rates) and partial linker substitution reveal strategies for tuning the phase behavior of both glass and glass–ceramic. These findings extend ZIF glass systems to second-row transition metal ions and underscore mechanochemical synthesis as a tool for tailoring the thermal properties of MOFs. This dual-phase functionality, combining glassy and crystalline domains of identical composition within a single material, offers potential for applications in thermal energy storage, phase change memory, and optics.

New paper just out @jacs.acspublications.org In his 3rd first-author paper from his PhD, Wen-Long Xue shows that mechanochemical synthesis enables melting & glass formation of a Cd-based MOF, plus controlled nanocrystal growth to form MOF glass-ceramics. A great team effort!
doi.org/10.1021/jacs...

We start our first post on Bluesky with a firework! Very proud of a brilliant team to publish our work on C(sp3)-atom transfer @science.org. www.science.org/doi/10.1126/... It has been a very exciting journey. Thanks @erc.europa.eu

Defect Identification in Zeolitic Imidazolate Framework Glasses by Solid-State NMR Spectroscopy Using 13CO2 as Probe Melt-quenched glasses from zeolitic imidazolate frameworks (ZIFs), a subset of metal–organic frameworks (MOFs) constructed from imidazolate linkers and divalent metal ions, represent a novel class of ...

Beware of the defects in ZIFs and their glasses ⚠️ With @henkegroup.bsky.social
and the Brunner group @tudresden.bsky.social by NMR we observed that dangling linker imidazoles react with CO2 to form carbamates during adsorption studies - now in Chem. Mater. @acs.org !
pubs.acs.org/doi/10.1021/...

Square-triangle tilings could be an infinite topological playground for 2D COFs, but they require precise linker size matching to work. Here we present a system, where we see evidence of linker mixing and heteroepitaxy due to size matching.

Sodium-Ion-Modified Zeolitic Imidazolate Framework Glasses Modifying glass compositions is key to creating silicate-based glasses for technologies like optical fibres, catalytic supports, protective coatings, and separation membranes. Here, we extend this con...

Here’s our second post!

Thrilled to share our second preprint of the year: a new method for modifying metal-organic framework glasses, complete with detailed structural analysis of the modified materials. A true team effort with amazing collaborators! Check it out here: doi.org/10.26434/che...