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Control sobre la separación de cargas en los conjugados de ftaalocianina-antraquinona en función del estado de
Andreas Gouloumis1, David González-Rodríguez, Purificación Vázquez
1Departamento de Química Organica, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
Journal of the American Chemical Society
|September 28, 2006
Resumen
Hemos sintetizado tres sistemas isoméricos donante-aceptor con las unidades de ftaalocianina (Pc) y antraquinona (AQ). Su topología dicta las interacciones electrónicas y la cinética de transferencia de carga, influenciadas por la agregación.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- Electrónica orgánica y electrónica orgánica.
- La fotoquímica es la fotoquímica.
Sus antecedentes:
- Los sistemas de donante-aceptor son cruciales para los dispositivos electrónicos orgánicos.
- La ftaalocianina (Pc) y la antraquinona (AQ) son bloques de construcción comunes.
- El control de la topología molecular tiene un impacto en las propiedades electrónicas.
Objetivo del estudio:
- Para sintetizar y caracterizar tres sistemas isoméricos de donante-aceptor Pc-AQ.
- Investigar la influencia de la topología molecular en las interacciones electrónicas intramoleculares e intermoleculares.
- Para estudiar el efecto de la agregación en la cinética de transferencia de electrones fotoinducida.
Principales métodos:
- Las técnicas electroquímicas son técnicas electroquímicas.
- Las mediciones fotofísicas.
- El análisis espectroscópico.
- Modelado computacional (implícito)
Principales resultados:
- Sintetizó tres isómeros de Pc-AQ con topologías distintas (envasado vs. extendido).
- Se observaron fuertes interacciones inter-Pc en el isómero envasado (1b) y una eficiente conjugación pi en los isómeros extendidos (1a, 1c).
- Se demostró que la fotoexcitación conduce a un estado de transferencia de carga Pc•+-AQ•−, con una cinética dependiente de la agregación.
Conclusiones:
- La topología molecular modula significativamente la comunicación electrónica y el acoplamiento excitónico.
- La agregación en disolventes aromáticos (formando oligómeros de tipo J) influye en la dinámica de transferencia de carga.
- Estos hallazgos ofrecen información sobre el diseño de materiales funcionales basados en una arquitectura molecular controlada.
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