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Control fotocrómico de la transferencia de electrones inducida por la luz. El interruptor molecular de doble

Stephen D Straight¹, Joakim Andréasson, Gerdenis Kodis

¹Department of Chemistry and Biochemistry, Center for the Study of Early Events in Photosynthesis, Arizona State University, Tempe, Arizona 85287, USA.

Journal of the American Chemical Society

|February 24, 2005

Resumen

Los investigadores desarrollaron un interruptor molecular utilizando una porción fotocrómica para controlar la transferencia de electrones fotoinducida. Este interruptor, basado en una tríada de porfirina-C(60) con un componente de dihidroindolizina, puede controlarse de manera reversible con luz.

Área de la Ciencia:

Química supramolecular de las moléculas.
La fotoquímica es la fotoquímica.
La electrónica molecular es la electrónica molecular.

Sus antecedentes:

El desarrollo de interruptores moleculares es crucial para los materiales funcionales avanzados.
La transferencia de electrones fotoinducida (PET) es un proceso clave en la conversión de energía y en los dispositivos moleculares.
El control de las vías PET es esencial para dirigir las funciones moleculares.

Objetivo del estudio:

Para diseñar y sintetizar un interruptor molecular de doble lanzamiento.
Para utilizar una fracción fotocrómica para dirigir la transferencia de electrones fotoinducida.
Para lograr un control reversible sobre las vías de separación de carga.

Principales métodos:

Síntesis de una tríada molecular compuesta por un aceptor de porfirina (P), C ((60)), y fotocromo de dihidroindolizina (DHI).
Fotoexcitación de la fracción de porfirina para iniciar la transferencia de electrones fotoinducida.
Fotoisomerización de la fracción DHI utilizando luz UV para alterar las vías de transferencia de electrones.

Principales resultados:

El sistema DHI-P-C(60) exhibió PET con una constante de tiempo de 2,3 ns y un rendimiento cuántico del 82%.
La isomerización inducida por la luz UV a la forma de betaína (BT), que conduce a un PET más rápido (56 ps) con un rendimiento del 99% en BT-P-C 60).
El cambio reversible entre las formas DHI y BT se logró utilizando luz visible o estímulos térmicos, lo que permite múltiples ciclos.

Conclusiones:

Se ha preparado con éxito un interruptor molecular funcional capaz de dirigir la separación de carga fotoinducida.
La fotoisomerización de la fracción de dihidroindolizina proporciona un control reversible sobre las vías de transferencia de electrones.
El interruptor molecular desarrollado demuestra el potencial para aplicaciones en electrónica molecular y almacenamiento de datos.

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