Negative cooperativity upon hydrogen bond-stabilized O<sub>2</sub> adsorption in a redox-active metal-organic framework.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32555184.
- Also identified by DOI 10.1038/s41467-020-16897-z and PMC identifier 7303157.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The design of stable adsorbents capable of selectively capturing dioxygen with a high reversible capacity is a crucial goal in functional materials development. Drawing inspiration from biological O<sub>2</sub> carriers, we demonstrate that coupling metal-based electron transfer with secondary coordination sphere effects in the metal-organic framework Co<sub>2</sub>(OH)<sub>2</sub>(bbta) (H<sub>2</sub>bbta = 1H,5H-benzo(1,2-d:4,5-d')bistriazole) leads to strong and reversible adsorption of O<sub>2</sub>. In particular, moderate-strength hydrogen bonding stabilizes a cobalt(III)-superoxo species formed upon O<sub>2</sub> adsorption. Notably, O<sub>2</sub>-binding in this material weakens as a function of loading, as a result of negative cooperativity arising from electronic effects within the extended framework lattice. This unprecedented behavior extends the tunable properties that can be used to design metal-organic frameworks for adsorption-based applications.