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Observación magnética de la unión aniónica en complejos de coordinación de hierro: hacia quimiosensores con
Zhaoping Ni1, Matthew P Shores
1Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA.
Journal of the American Chemical Society
|December 17, 2008
Resumen
Los complejos de espín-cruzamiento pueden detectar la unión de aniones en solución. Este estudio muestra que un complejo de hierro cambia de color y estado de espín tras la interacción de aniones, lo que permite la detección de anfitrión-invitado basada en magnetometría.
Área de la Ciencia:
- Coordinación Química de la Coordinación
- Química supramolecular de las moléculas.
- Ciencia de los materiales Ciencia de los materiales.
Sus antecedentes:
- Los complejos de espín-crossover (SCO) son sensibles a los estímulos ambientales.
- El reconocimiento de aniones en solución es crucial para la detección química.
- El desarrollo de materiales receptivos para las interacciones huésped-anfitrión es un área de investigación activa.
Objetivo del estudio:
- Demostrar el uso de los complejos SCO para reportar eventos de unión de aniones en solución.
- Para investigar la correlación entre la fuerza de unión de aniones y la conmutación del estado de espín.
- Explorar la combinación sinérgica de reconocimiento de aniones y conmutación de estado de espín para aplicaciones de detección.
Principales métodos:
- Síntesis y caracterización del hierro catiónico ((II) complejo SCO [Fe (((H ((2) bip) ((3))) ((BPh ((4))) ((2).
- Análisis espectroscópico (UV-Vis) para observar cambios de color tras la adición de aniones a temperatura ambiente.
- Mediciones de susceptibilidad magnética de temperatura variable para estudiar las transiciones de estado de giro a -40 grados C.
- Evaluación de las interacciones de enlace de hidrógeno entre el receptor y varios aniones.
Principales resultados:
- El complejo de hierro exhibe sutiles cambios de color en la solución de diclorometano al interactuar con los aniones de enlace de hidrógeno.
- A -40 grados C, la unión de aniones induce una transición del estado de espín alto al estado de espín bajo.
- La magnitud del cambio de estado de giro se correlaciona cualitativamente con la fuerza de la interacción anfitrión-invitado.
- Se observó un efecto sinérgico entre el reconocimiento de aniones y la conmutación del estado de espín.
Conclusiones:
- Los complejos de espín-crossover se pueden utilizar como sondas sensibles para la detección de aniones en solución.
- El reconocimiento combinado de aniones y la conmutación del estado de espín proporcionan un nuevo mecanismo de detección.
- La magnetometría se puede emplear para cuantificar las interacciones huésped-anfitrión basadas en el comportamiento de SCO.
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