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La transferencia de hidruro fotointercambiable desde el iridio a la 1-metilnicotinamida racionalizada por ciclos
Seth M Barrett1, Catherine L Pitman, Andrew G Walden
1Department of Chemistry, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-3290, United States.
Journal of the American Chemical Society
|October 10, 2014
Resumen
La luz visible activa un potente complejo de iridio para transferir el hidruro, mejorando su capacidad de donante. Esta reacción fototriggered permite la reducción controlada de las moléculas orgánicas y la liberación de H2.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- La fotoquímica es la fotoquímica.
- Síntesis orgánica La síntesis orgánica.
Sus antecedentes:
- Los complejos de iridio son catalizadores versátiles.
- La transferencia de hidrógeno es crucial en las reacciones orgánicas.
- La fotoquímica de la luz visible ofrece rutas sintéticas sostenibles.
Objetivo del estudio:
- Para investigar la transferencia de hidruro desencadenada por luz visible de un complejo de iridio.
- Para cuantificar la capacidad (hidricidad) del donante de hidruro en estado excitado.
- Para explorar la reducción fotointercambiable de sustratos orgánicos.
Principales métodos:
- Síntesis y caracterización del complejo de iridio [Cp*Ir(bpy) ((H) ] ((+).
- Utilizó un nuevo ciclo termoquímico para predecir la hidricidad del estado excitado.
- Realizó experimentos fotoquímicos con ácidos orgánicos y 1-metilnicotinamida (MNA(+)).
Principales resultados:
- Se observó la liberación fototriggerada de H2 del complejo de iridio en presencia de ácidos orgánicos.
- Demostró un aumento significativo en la hidricidad (≥18 kcal/mol) en el estado excitado.
- Se mostró la transferencia de hidruro fotointercambiable a MNA (((+), controlando la formación del producto.
Conclusiones:
- El complejo de iridio actúa como un potente fotohidruro bajo luz visible.
- La hidricidad en estado excitado puede ser significativamente mejorada, permitiendo una nueva reactividad.
- La luz visible ofrece un control preciso sobre las reacciones de transferencia de hidruro y la selectividad del producto.
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