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La conmutación reversible de un complejo de cobalto por estímulos térmicos, de presión y electroquímicos: cruce de
Matthew G Cowan1, Juan Olguín, Suresh Narayanaswamy
1Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
Journal of the American Chemical Society
|November 9, 2011
Resumen
Este estudio introduce un complejo de cobalto tres veces conmutable, [Co(II) ((dpzca) ((2)), exhibiendo un cruce de espín reversible provocado por cambios de temperatura, presión y redox. Este comportamiento de conmutación magnética ofrece potencial para aplicaciones avanzadas de materiales.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Ciencia de los materiales Ciencia de los materiales.
- Magnetoquímica es la Magnetoquímica.
Sus antecedentes:
- Los materiales de cruce de espín (SCO) son de interés para interruptores moleculares y dispositivos de memoria.
- Se sabe que los complejos de cobalto (II) exhiben fenómenos de cruce de espín.
- El control del comportamiento SCO a través de múltiples estímulos es crucial para las aplicaciones prácticas.
Objetivo del estudio:
- Sintetizar y caracterizar un nuevo complejo de cobalto (II) con propiedades magnéticas conmutables.
- Para investigar el comportamiento de cruce de espín del complejo inducido por la temperatura, la presión y los estímulos redox.
- Explorar el potencial de este complejo como un material sensible a múltiples estímulos.
Principales métodos:
- Síntesis y caracterización estructural del complejo [Co(II) ((dpzca) ((2)).
- Mediciones de susceptibilidad magnética de temperatura variable para estudiar el cruce de espín.
- Estudios de alta presión para investigar las transiciones de giro inducidas por la presión.
- Titraciones de redox y mediciones magnéticas para explorar la conmutación desencadenada por redox.
Principales resultados:
- El complejo [Co{II}{dpzca}{II}] exhibe un cruce de espín abrupto, reversible e histérico entre los estados de cobalto de alto espín (HS) y bajo espín (LS).
- La transición de giro se desencadena efectivamente por los cambios de temperatura (T(1/2) ↓ = 168 K, T(1/2)↑ = 179 K).
- El complejo demuestra el cambio de espín reversible inducido por la presión y los estímulos redox, lo que permite las transiciones entre el cobalto HS (II) y el cobalto LS (III).
Conclusiones:
- El complejo [Co ((II) ((dpzca) ((2)) ] es un material SCO con triple conmutación.
- Sus distintos mecanismos de conmutación (temperatura, presión, redox) resaltan su potencial para materiales funcionales avanzados.
- La caracterización estructural de los estados HS y LS proporciona información sobre el mecanismo de la OCS.
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