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El complejo A Tris (diisocianuro) de cromo es un análogo luminiscente del Fe (2,2'-bipiridina)
Laura A Büldt1, Xingwei Guo1, Raphael Vogel1
1Department of Chemistry, University of Basel , St. Johanns-Ring 19 and Spitalstrasse 51, 4056 Basel, Switzerland.
Journal of the American Chemical Society
|January 6, 2017
Resumen
Un nuevo complejo de cromo con ligandos quelantes exhibe luminiscencia y una notable estabilidad, ofreciendo potencial como una alternativa abundante en la tierra a los metales preciosos en células solares y aplicaciones de iluminación.
Área de la Ciencia:
- Química organometálica
- Ciencias de los materiales
- La fotoquímica
Sus antecedentes:
- Los complejos de hierro (II) son sensibilizadores abundantes en la tierra para las células solares sensibilizadas con tintes, pero su vida útil en estado excitado es limitada.
- Los metales preciosos se usan a menudo en dispositivos luminiscentes y células solares, lo que impulsa la investigación de alternativas abundantes en la tierra.
- Estabilizar estados de baja oxidación de metales de transición como el cromo es un desafío, pero ofrece propiedades electrónicas únicas.
Objetivo del estudio:
- Sintetizar y caracterizar un nuevo complejo de cromo ((0) con ligandos de isocianuro quelatantes bidentados.
- Investigar las propiedades fotofísicas, la estabilidad y las capacidades fotorreductivas del nuevo complejo.
- Explorar el potencial de este complejo abundante en la tierra como sustituto de los metales preciosos en aplicaciones tecnológicas.
Principales métodos:
- Síntesis de un ligando quelante bidentado (CNtBuAr3NC) con un eje meta-terfenílico.
- Formación del complejo homoleptico de cromo ((0)), Cr ((CNtBuAr3NC) 3.
- Caracterización fotofísica que incluye mediciones de la luminiscencia durante toda la vida y estudios de aniquilación triplet-triple.
- Análisis electroquímico para determinar el potencial de oxidación en estado excitado.
Principales resultados:
- El complejo sintetizado Cr ((CNtBuAr3NC) 3 es estable y luminiscente a temperatura ambiente.
- El complejo exhibe una vida útil de estado excitado significativamente larga (2,2 ns), superando a los complejos de hierro isoelectrónicos.
- Cr(CNtBuAr3NC) 3 demuestra una mayor robustez frente a la fotodegradación en comparación con otros complejos Cr(0).
- Se observó una transferencia de energía eficiente y una conversión ascendente de aniquilación triplet-triple con antraceno.
- El complejo actúa como un potente fotorreducente con un potencial de oxidación en estado excitado de -2,43 V frente a Fc+/Fc.
Conclusiones:
- El nuevo ligando quelante de bidentato estabiliza eficazmente el cromo en su estado zerovalente.
- Cr ((CNtBuAr3NC) 3 muestra propiedades prometedoras para aplicaciones en dispositivos luminiscentes y células solares sensibilizadas con tintes.
- Esta investigación pone de relieve el potencial de los complejos de cromo abundantes en la tierra como alternativas sostenibles a los metales preciosos.
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