Consecutive Single-Crystal-to-Single-Crystal Isomerization of Novel Octamolybdate Anions within a Microporous Hybrid Framework with Robust Water Sorption Properties
The 3D hybrid framework [{Cu(cyclam)}3(κ-Mo8O27)] ⋅ 14H2O (1) (cyclam=1,4,8,11-tetraazacyclotetradecane) undergoes sequential single-crystal-to-single-crystal transformations upon heating to afford two different anhydrous phases (2 a and 3 a). These transitions modify the framework dimensionality an...
| Autores: | , , , , , , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2023 |
| País: | España |
| Recursos: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:addi.ehu.eus:10810/63400 |
| Acesso em linha: | http://hdl.handle.net/10810/63400 |
| Access Level: | acceso abierto |
| Palavra-chave: | microporous materials polyoxometalates single-crystal-to-single-crystal solid-state isomerization water sorption |
| Resumo: | The 3D hybrid framework [{Cu(cyclam)}3(κ-Mo8O27)] ⋅ 14H2O (1) (cyclam=1,4,8,11-tetraazacyclotetradecane) undergoes sequential single-crystal-to-single-crystal transformations upon heating to afford two different anhydrous phases (2 a and 3 a). These transitions modify the framework dimensionality and enable the isomerization of κ-octamolybdate (κ-Mo8) anions into λ (2 a) and μ (3 a) forms through metal migration. Hydration of 3 a involves condensation of one water molecule to the cluster to afford the γ-Mo8 isomer in 4, which dehydrates back into 3 a through the 6 a intermediate. In contrast, 2 a reversibly hydrates to form 5, exhibiting the same Mo8 cluster as that of 1. It is remarkable that three of the Mo8 clusters (κ, λ and μ) are new and that up to three different microporous phases can be isolated from 1 (2 a, 3 a, and 6 a). Water vapor sorption analyses show high recyclability and the highest uptake values for POM-based systems. The isotherms display an abrupt step at low humidity level desirable for humidity control devices or water harvesting in drylands. |
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