Guest-, light- and thermally-modulated spin crossover in [Fe-2(II)] supramolecular helicates
A new bis(pyrazolylpyridine) ligand (H2L) has been prepared to form functional [Fe-2(H2L)(3)](4+) metallohelicates. Changes to the synthesis yield six derivatives, X@[Fe-2(H2L)(3)]X(PF6)(2)center dot xCH(3)OH (1, x = 5.7 and X = Cl; 2, x = 4 and X = Br), X@[Fe-2(H2L)(3)]X(PF6)(2)center dot yCH(3)OH...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2016 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/153819 |
| Acceso en línea: | https://hdl.handle.net/2445/153819 |
| Access Level: | acceso abierto |
| Palabra clave: | Ferro Lligands Química supramolecular Iron Ligands Supramolecular chemistry |
| Sumario: | A new bis(pyrazolylpyridine) ligand (H2L) has been prepared to form functional [Fe-2(H2L)(3)](4+) metallohelicates. Changes to the synthesis yield six derivatives, X@[Fe-2(H2L)(3)]X(PF6)(2)center dot xCH(3)OH (1, x = 5.7 and X = Cl; 2, x = 4 and X = Br), X@[Fe-2(H2L)(3)]X(PF6)(2)center dot yCH(3)OH center dot H2O (1a, y = 3 and X = Cl; 2a, y = 1 and X = Br) and X@[Fe-2(H2L)(3)](I-3)(2)center dot 3Et(2)O (1b, X = Cl; 2b, X = Br). Their structure and functional properties are described in detail by single-crystal X-ray diffraction experiments at several temperatures. Helicates 1a and 2a are obtained from 1 and 2, respectively, by a single-crystal-to-single-crystal mechanism. The three possible magnetic states, [LS-LS], [LS-HS], and [HS-HS] can be accessed over large temperature ranges as a result of the structural non-equivalence of the FeII centers. The nature of the guest (Cl- vs. Br-) shifts the spin crossover (SCO) temperature by roughly 40 K. Also, metastable [LS-HS] or [HS-HS] states are generated through irradiation. All helicates (X@[Fe-2(H2L)(3)])(3+) persist in solution. |
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