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[(DPEPhos)(bcp)Cu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
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Definición de la estructura electrónica y geométrica de los complejos de cobre-bis-fenoxido oxidados por un electrón
Tim Storr1, Pratik Verma, Russell C Pratt
1Department of Chemistry, Stanford University, Stanford, California 94305, USA.
Journal of the American Chemical Society
|October 23, 2008
Resumen
El complejo de cobre [CuSal](+) exhibe un locus de oxidación basado en metales, formando Cu(III) en sólidos y un equilibrio de espín entre Cu(II) y Cu(III) en solución. La estructura del ligando influye significativamente en el sitio de oxidación en los complejos de cobre.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Coordinación Química de la Coordinación
- La espectroscopia es una técnica de espectroscopia.
Sus antecedentes:
- La estructura electrónica de los complejos metálicos con ligandos no inocentes es crucial para comprender su reactividad.
- Distinguir entre la oxidación basada en metales y la basada en ligandos es un desafío clave en la química de coordinación.
- Los complejos de cobre con ligandos de tipo salen son conocidos por sus diversas propiedades electrónicas.
Objetivo del estudio:
- Para investigar la estructura geométrica y electrónica de un complejo de cobre oxidado, [CuSal](+).
- Para determinar el lugar de oxidación (metal vs. ligando) en el complejo de cobre.
- Para explorar la influencia de la estructura de ligando en el sitio de oxidación en complejos de cobre-bis-fenoxido.
Principales métodos:
- Espectroscopia UV-Vis-NIR Espectroscopía UV-Vis-NIR Espectroscopía UV-Vis-NIR Espectroscopía UV-Vis-NIR Espectroscopía UV-Vis-NIR Espectroscopía UV-Vis-NIR Espectroscopía UV-Vis-NIR Espectroscopía UV-NIR Espectroscopía
- Mediciones de la susceptibilidad magnética.
- La electroquímica es electroquímica.
- Resonancia Espectroscopia Raman de resonancia Espectroscopia Raman de resonancia Espectroscopia Raman de resonancia Espectroscopia Raman de resonancia Espectroscopia Raman de resonancia
- Cristalografía de rayos X con rayos X.
- La espectroscopia de absorción de rayos X es una espectroscopia de absorción de rayos X.
- Teoría funcional de la densidad (DFT) cálculos.
Principales resultados:
- El complejo de cobre oxidado [CuSal](+) forma exclusivamente una especie Cu(III) en estado sólido.
- En solución, [CuSal](+) muestra un equilibrio de espín reversible entre las formas Cu(II) -ligando-radical y Cu(III).
- El ligando bis-imine-bis-fenolato estabiliza el estado de oxidación Cu(III) y facilita el equilibrio de espín sin cambios de coordinación.
- Un análogo de tetrahidrosalen relacionado, [CuSal(rojo) ](+), existe como un complejo Cu(II) -ligando-radical invariable en la temperatura.
Conclusiones:
- El lugar de oxidación en [CuSal](+) es principalmente a base de metal, formando Cu(III) en estado sólido.
- Los estudios de soluciones revelan un equilibrio de espín único para [CuSal] ((+), lo que indica estados casi isoenergéticos Cu ((II) -radical y Cu ((III)).
- El diseño de los ligandos juega un papel crítico en el control del sitio de oxidación y el comportamiento electrónico de los complejos de cobre.
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