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Published on: August 7, 2018
Reactividad de transferencia de electrones mejorada de los complejos de manganeso no hemo (IV) -oxo mediante la unión
Heejung Yoon1, Yong-Min Lee, Xiujuan Wu
1Department of Material and Life Science, Graduate School of Engineering, ALCA, Japan Science and Technology Agency, Osaka University, Suita, Osaka 565-0871, Japan.
Journal of the American Chemical Society
|June 8, 2013
Resumen
Los iones escandio (Sc3+) mejoran significativamente las tasas de transferencia de electrones de los complejos manganeso-oxo. Esta unión altera los mecanismos de reacción, aumentando la actividad catalítica en las reacciones de oxidación.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- La catálisis de la catálisis.
- Química bioorgánica Química bioorgánica.
Sus antecedentes:
- Los complejos manganeso-oxo no hemo son cruciales en la catálisis de la oxidación.
- Comprender la influencia de la unión de iones metálicos en la reactividad es clave para el diseño de catalizadores.
Objetivo del estudio:
- Investigar el efecto de la unión del ion escandio (Sc3+) en las propiedades electrónicas y la reactividad de los complejos de manganeso (IV) - oxo.
- Para dilucidar los cambios mecánicos inducidos por la coordinación de Sc3+ en las reacciones de oxidación.
Principales métodos:
- Se emplearon técnicas espectroscópicas (por ejemplo, UV-Vis, EPR) para caracterizar los complejos.
- Los cálculos de la Teoría Funcional de Densidad (DFT) se utilizaron para analizar las estructuras electrónicas y las interacciones de enlace.
- La cinética de transferencia de electrones se estudió utilizando el análisis de la teoría de Marcus con varios donantes de electrones.
Principales resultados:
- Los iones escandio (Sc3+) se unen fuertemente a los complejos de manganeso (IV) -oxo, formando las especies Mn (IV) (O) -Sc3+) 1 y Mn (IV) (O) -Sc3+) 2.
- La unión de Sc3+ aumenta significativamente los potenciales de reducción de un electrón de los complejos de manganeso.
- Las velocidades de reacción de transferencia de electrones se incrementaron hasta 10^7 veces con la unión de dos iones Sc3+, atribuido a menores energías de reorganización y mayores potenciales de reducción.
Conclusiones:
- La coordinación de iones de escandio mejora dramáticamente la reactividad de transferencia de electrones de los complejos de manganeso (IV) - oxo.
- La unión de iones Sc3+ puede cambiar el mecanismo de reacción de la transferencia directa de átomos de oxígeno a una vía de transferencia de electrones en las reacciones de sulfoxidación.
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