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La homólisis del enlace N-O de un hierro (II) complejo TEMPO produce un hierro (III) oxo intermedio
Jeremy M Smith1, Derick E Mayberry, Charles G Margarit
1Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces New Mexico 88003, USA. jesmith@nmsu.edu
Journal of the American Chemical Society
|March 29, 2012
Resumen
Los investigadores reaccionaron TEMPO con un complejo de hierro, formando un complejo de nitróxido de hierro estable. Este complejo se somete a termólisis para producir un hierro activo (III) oxo intermedio para las reacciones de transferencia de átomos de oxígeno.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Mecanismos de reacción Mecanismos de reacción
Sus antecedentes:
- Los complejos estables de hierro son cruciales para la catálisis.
- Comprender la reactividad del hierro en diferentes estados de oxidación es clave.
- TEMPO (2,2,6,6-tetramethylpiperidin-1-yl) oxyl es un radical estable utilizado en varias transformaciones químicas.
Objetivo del estudio:
- Para sintetizar y caracterizar una novela de hierro ((I) -TEMPO adduct.
- Para investigar las vías de reactividad y descomposición del complejo hierro-TEMPO.
- Explorar el potencial de los intermediarios de oxóferos de hierro en las reacciones de transferencia de átomos de oxígeno.
Principales métodos:
- Síntesis del hierro (I) precursor PhB (MesIm) y Fe (COE).
- Reacción del complejo de hierro (I) con TEMPO.
- Caracterización estructural mediante cristalografía y espectroscopia de rayos X (NMR, EPR, Mössbauer).
- Estudios de termólisis para inducir la homólisis del enlace N-O.
- Experimentos de captura con el radical trifenilmetil.
Principales resultados:
- Formación del complejo κ(1)-TEMPO PhB ((MesIm) ((3) Fe ((TEMPO) con hierro divalente unido a un anión nitróxido.
- El complejo es isoelectrónico a una especie de hierro (II) peroxo.
- La termólisis generó un intermediario de hierro (III) oxo.
- El intermediario oxo (III) de hierro demostró actividad en la transferencia de átomos de oxígeno.
- El intermedio oxo fue atrapado para formar un hierro ((II) complejo alkoxo PhB ((MesIm) ((3) Fe ((OCPh ((3)).
Conclusiones:
- Se sintetizó y caracterizó con éxito un nuevo complejo de nitróxido de hierro (II).
- La homólisis del enlace N-O del complejo de hierro (II) produce una especie reactiva de hierro (III) oxo.
- Este intermediario de oxo de hierro es capaz de transferir átomos de oxígeno, destacando su potencial catalítico.
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