A new {Fe4Co4} soluble switchable nanomagnet encapsulating Cs+: enhancing the stability and redox flexibility and tuning the photomagnetic effect
| Autor: | J. von Bardeleben, Lise-Marie Chamoreau, Yanling Li, M. Tricoire, D. Garnier, Juan-Ramón Jiménez, Yves Journaux, Rodrigue Lescouëzec |
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| Přispěvatelé: | Institut Parisien de Chimie Moléculaire (IPCM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Conception et application de molécules bioactives (CAMB), Université de Strasbourg (UNISTRA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Couches nanométriques : formation, interfaces, défauts (INSP-E5), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2017 |
| Předmět: |
Prussian blue
010405 organic chemistry Metal ions in aqueous solution Inorganic chemistry Photomagnetic effect Nuclear magnetic resonance spectroscopy 010402 general chemistry Photochemistry 01 natural sciences Nanomagnet 0104 chemical sciences Ion law.invention Inorganic Chemistry chemistry.chemical_compound chemistry law Single-molecule magnet [CHIM.OTHE]Chemical Sciences/Other Electron paramagnetic resonance |
| Zdroj: | Dalton Transactions Dalton Transactions, Royal Society of Chemistry, 2017, 46 (44), pp.15549-15557. ⟨10.1039/C7DT02989F⟩ Dalton Transactions, 2017, 46 (44), pp.15549-15557. ⟨10.1039/C7DT02989F⟩ |
| ISSN: | 1477-9234 1477-9226 |
| DOI: | 10.1039/c7dt02989f |
| Popis: | International audience; We report a new cyanide-bridged Cs⊂{Fe4Co4} box, a soluble model of photomagnetic Prussian blue analogues (PBAs). The Cs+ ion has a high affinity for the box and can replace the K+ ion in the preformed K-cube. This exchange is kinetically impeded at room temperature but is accelerated by heating and using the 18-crown-6 ether. The inserted Cs+ ion confers a high robustness to the cube, which withstands boiling, as shown by variable-temperature NMR studies. The stability of this model complex in solution allows the probing of the electronic interaction between the alkali ion and the cyanide cage by using various techniques. These interactions are known to play a role in the photomagnetic behaviour of PBAs. Firstly, the 133Cs NMR spectroscopy proves that there is an electronic communication between the encapsulated alkali ion and the cyanide cage. The measured up-field signal, observed at ca. −200 ppm at 300 K, reveals that a certain amount of spin density is transferred through the bonds from the paramagnetic Co(II) ion to the encapsulated cation. Secondly, cyclovoltammetric studies show that the nature of the inserted ions affects the redox properties of the cage and influences the electronic communication between the metal ions. However, the differences in the electrochemical properties of the K-cube and the Cs-cube remain moderate. As the switching properties are influenced by the redox potential of the Fe and Co centers, similar photomagnetic behaviour is observed, with both of them being highly photomagnetic. This result contrasts strikingly with previous studies on the 3D polymeric PBAs, where the PBAs with a high amount of Cs+ show poor photomagnetic behaviour. In that case, cooperative behaviour likely influences the switching properties. Finally, EPR spectroscopy shows that the K-cube is more anisotropic than the Cs-cube. This difference is reflected in the changes occurring in the slow magnetic relaxation (single molecule magnet behaviour) observed in the two cubes. |
| Databáze: | OpenAIRE |
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