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El nuevo diseño de ligandos proporciona deslocalización y promueve una fuerte absorción en toda la región visible en
Tyler J Whittemore1, Travis A White1, Claudia Turro1
1Department of Chemistry and Biochemistry, The Ohio State University , Columbus, Ohio 43210, United States.
Journal of the American Chemical Society
|December 21, 2017
Resumen
Un nuevo complejo de rutenio, Ru-qdpq, exhibe una absorción desplazada al rojo y un estado excitado de larga duración, a diferencia de un complejo relacionado. Este descubrimiento ofrece una vía para el desarrollo de materiales avanzados para la energía solar y la fotoquimioterapia.
Área de la Ciencia:
- Química de coordinación
- La fotofísica
- Ciencias de los materiales
Sus antecedentes:
- Los complejos de rutenio (II) con polipiridil y ligandos que contienen quinona son cruciales para las aplicaciones de recolección de luz y conversión de energía.
- Comprender la dinámica del estado excitado y la comunicación electrónica dentro de estos ligandos es clave para afinar sus propiedades fotofísicas.
Objetivo del estudio:
- Para sintetizar y caracterizar un nuevo complejo Ru (II) -antraquinona, [Ru (bpy) 2 (qdpq) ]6) 2 (Ru-qdpq).
- Investigar las propiedades fotofísicas, particularmente las vidas en estado excitado y los espectros de absorción, de Ru-qdpq en comparación con un complejo relacionado, Ru-qdppz.
- Para aclarar el papel de los modos de coordinación de ligandos en el dictado de la comunicación electrónica y el comportamiento de estado excitado.
Principales métodos:
- Síntesis y caracterización de los complejos Ru-qdpq y Ru-qdppz.
- Espectroscopia de absorción en estado estacionario para determinar los máximos de absorción y los desplazamientos espectrales.
- Espectroscopia ultrarrápida y mediciones con resolución temporal para analizar la dinámica del estado excitado y las vidas.
- Cálculos de electroquímica y teoría funcional de la densidad (DFT) para sondear estructuras y propiedades electrónicas.
Principales resultados:
- Ru-qdpq muestra una fuerte absorción de MLCT a 546 nm, significativamente desplazada hacia el rojo en comparación con Ru-qdppz (λmax = 450 nm).
- Ru-qdpq exhibe un estado excitado MLCT de larga duración (τ = 19 ns) con una densidad de electrones deslocalizada en el ligando qdpq.
- Ru-qdppz muestra estados excitados de vida más corta (τ = 362 ps) debido a estados electrónicamente aislados dentro del ligando.
Conclusiones:
- La coordinación única de los ligandos qdpq y qdppz conduce a distintas vías de comunicación electrónica, que influyen en las propiedades de estado excitado y transferencia de electrones.
- La absorción desplazada al rojo y el estado excitado de larga duración de Ru-qdpq presentan una plataforma prometedora para el desarrollo de nuevos materiales.
- Estos hallazgos allanan el camino para el diseño de complejos con propiedades fotofísicas sintonizables para aplicaciones en la conversión de energía solar y la fotoquimioterapia.
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