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Complejos luminiscentes bimetálicos de oro de dos coordenadas que utilizan carbenos de Janus
Jie Ma1, Jonas Schaab2, Sritoma Paul3
1Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089, United States.
Journal of the American Chemical Society
|August 29, 2023
Resumen
Los nuevos complejos bimetálicos carbeno-metal-amida (cMa) ofrecen un diseño para materiales luminiscentes eficientes. Estos complejos muestran altas eficiencias de fotoluminiscencia y velocidades de radiación rápidas, adecuadas para dispositivos orgánicos emisores de luz (OLED).
Área de la Ciencia:
- Ciencias de los materiales
- La fotoquímica
- Química inorgánica
Sus antecedentes:
- Los complejos carbeno-metal-amida (cMa) se exploran para los materiales luminiscentes.
- El diseño de materiales con grandes fuerzas de oscilador y pequeñas diferencias de energía singlet-triplet (ΔEST) es crucial para una emisión de luz eficiente.
Objetivo del estudio:
- Sintetizar y caracterizar nuevos complejos bimetálicos cMa con ligandos puente de biscarbenos.
- Investigar sus propiedades fotofísicas para aplicaciones potenciales en materiales luminiscentes y dispositivos orgánicos emisores de luz (OLED).
Principales métodos:
- Síntesis de complejos bimetales con la estructura general (R2N) Au(:carbeno─carbeno:) Au(NR2).
- Análisis detallado de los espectros de absorción y emisión dependientes de la solvación.
- Medición de la vida útil de las emisiones, las eficiencias de la fotoluminiscencia y las tasas de radiación.
- Estudios de luminiscencia dependientes de la temperatura para determinar el tiempo de vida del estado singular y ΔEST.
- Fabricación y ensayo de OLEDs procesados en solución utilizando los complejos como dopantes.
Principales resultados:
- Los complejos cMa bimetales exhiben propiedades ópticas dependientes de la solvación.
- La absorción molar se correlaciona con la barrera de energía para la rotación del enlace metal-ligando.
- Se observaron altas eficiencias de fotoluminiscencia (ΦPL > 95%) y cortas vidas de emisión (200-300 ns).
- Las tasas de radiación son 3-4 veces más rápidas que las análogas monometálicas.
- Se determinó una pequeña ΔEST (40-50 meV) y una vida útil del estado singular (τS) cercana a 12 ns.
- Los OLED demostraron una alta eficiencia y un bajo roll-off a alta luminancia.
Conclusiones:
- Los complejos bimetálicos cMa presentados proporcionan una estrategia de diseño general para materiales luminiscentes con ΔEST optimizado y altas tasas de radiación.
- Estos complejos son candidatos prometedores para OLED de alto rendimiento procesados por solución.
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