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Complejos estructuralmente diversos de paladio ligado al diazafluoreno (II) y sus implicaciones para las reacciones

Paul B White¹, Jonathan N Jaworski¹, Charles G Fry¹

¹Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.

Journal of the American Chemical Society

|March 12, 2016

Resumen

El ligando 4,5-diazafluoreno-9-one (DAF) cambia rápidamente entre los modos de coordinación con el paladio, lo que explica su eficacia en las reacciones de oxidación catalizadas por Pd.

Área de la Ciencia:

Química organometálica
Catálisis
Química de coordinación

Sus antecedentes:

El 4,5-Diazafluoreno-9-one (DAF) es un ligando eficaz en las reacciones de oxidación catalizadas por el paladio.
La base mecanicista de la utilidad de DAF no está clara.

Objetivo del estudio:

Para aclarar la química de coordinación de DAF con las sales de carboxilato de paladio.
Comprender la base mecanicista de la eficacia del DAF en las reacciones de oxidación catalizadas por Pd.

Principales métodos:

Caracterización de múltiples complejos Pd (II) -DAF utilizando espectroscopia de RMN y cristalografía de rayos X.
Estudios de titulación de DAF con acetato de paladio (PdOAc) 2.
Investigación de los derivados de DAF y de los ligandos carboxilados alternativos.

Principales resultados:

Se identificaron múltiples complejos monoméricos y diméricos Pd(II), que exhiben diversos modos de coordinación DAF (monodentado, bidentado, puente).
El comportamiento de coordinación de DAF fue influenciado por su concentración y la presencia de otros ligandos.
Se observó una simplificación estructural con los derivados DAF ricos en electrones y diferentes carboxilatos.

Conclusiones:

El DAF exhibe un rápido equilibrio entre los diversos modos de coordinación con los centros Pd{II).
Este comportamiento dinámico de coordinación proporciona información clave sobre el papel de DAF como ligando en las reacciones de oxidación catalizadas por paladio.

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