Programmable porous materials using chalcogen bonds

Colorado School of Mines researchers reported on May 15 that they had built a permanently porous organic framework assembled and stabilized solely through chalcogen bonds, a class of weak noncovalent interactions better known in molecular recognition than in bulk materials. The paper appeared that day in *Nature Synthesis*, and the authors said the framework’s pore structure and electronic behavior point to a broader design strategy for porous solids. Social posts over the weekend pointed to an earlier ChemRxiv version of the work, but the study is now in a peer-reviewed journal. ### What exactly did the team make? The paper describes a “permanently porous chalcogen-bonded organic framework,” or ChOF, built from 1,2,5-telluradiazole-containing molecular units that self-assemble into a honeycomb-type network. The authors said the structure is held together by noncovalent tellurium-to-nitrogen contacts rather than the covalent or metal-ligand bonds more commonly used in porous frameworks. (nature.com) Colorado School of Mines said the material is called Trip3Tez-I. Hannah Martin, a Mines Ph.D. candidate and coauthor, said electron diffraction confirmed both the permanent pores and the bonding motif that holds the solid together. The school said those pores are about two nanometers wide. ### Why are chalcogen bonds unusual in a porous framework? (chemrxiv.org) Nature Synthesis said the framework is assembled solely by chalcogen bonding, making it a rare example of a porous solid built entirely from that interaction. Chalcogen bonding refers to attractive noncovalent interactions involving chalcogen atoms such as sulfur, selenium or tellurium; in this case, the key contact is Te···N. (minesnewsroom.com) The authors wrote that material-design “toolboxes” have changed little since dynamic covalent chemistry emerged decades ago, and they presented chalcogen bonding as a distinct mode of interatomic connectivity for functional materials. That claim is theirs, not an outside assessment, but it captures why the paper has drawn attention beyond supramolecular chemistry. ### What did the experiments show beyond the structure? (nature.com) The journal abstract said empirical and computational studies examined electronic structure, structural healing and lattice dynamics in the new framework. The Colorado School of Mines summary added gas adsorption to that list and said the team found properties that could be relevant to semiconducting behavior. C. Michael McGuirk, the paper’s corresponding author and a chemistry professor at Mines, said the work could open a new line of materials research. (chemrxiv.org) Martin said the weaker, reversible nature of chalcogen-bond interactions may allow materials to be dissolved and re-formed, unlike many rigid semiconducting solids. Both comments point to possible uses, but the reported results are still laboratory demonstrations rather than product-ready devices. (nature.com) ### Did the paper actually prove battery and gas-filter applications? The published sources support the gas-adsorption angle more clearly than the battery claim. The paper abstract and related summaries refer to porous behavior, adsorption studies and charge-transport-relevant electronic properties, while the school’s release mentions potential semiconducting uses and regenerative behavior. (minesnewsroom.com) No source reviewed here says the team demonstrated a working battery component. References to ion transport or battery uses appear to be extrapolations from the broader idea that programmable pores and weak directional bonding could matter in energy materials. Without a direct demonstration in the paper, that remains a prospective application rather than a reported result. ### Who was involved, and what comes next? (nature.com) The author list spans Colorado School of Mines, the University of Oregon, the University of Southampton, North Carolina State University, the National Institute of Standards and Technology, the National Renewable Energy Laboratory, the University of Delaware and Oak Ridge National Laboratory, according to the ChemRxiv manuscript. Brian J. Eckstein and Hannah R. Martin are listed as equal contributors, and McGuirk is the corresponding author. (nature.com) The next step is likely to be follow-on work on related chalcogen-bonded frameworks and property measurements, judging from the paper’s framing and the school’s release. As of May 18, the main record is the *Nature Synthesis* article published May 15, alongside the earlier ChemRxiv preprint version linked in social posts. (nature.com) (chemrxiv.org)