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La transferencia de átomos de O desde el óxido nítrico catalizado por Fe (TPP)
1Department of Chemistry, University of California, Irvine, California, 92697-2025, USA.
Journal of the American Chemical Society
|July 18, 2001
Resumen
La reacción de la tetrafenilporfirina de hierro de nitrosilo (NO-Fe(TPP)) con el gas óxido nítrico (NO) forma un adducto acoplado N--N transitorio. Este intermedio es clave para entender las transformaciones NO-Fe (TPP) y la potencial producción de N2O.
Área de la Ciencia:
- Química inorgánica y inorgánica.
- Química organometálica de las sustancias orgánicas.
- Mecanismos de reacción Los mecanismos de reacción.
Sus antecedentes:
- Las porfirinas de hierro de nitrosilo (NO-Fe ((TPP)) son importantes en la química de la coordinación.
- Comprender las vías de reacción de NO-Fe (TPP) con óxido nítrico (NO) es crucial para las aplicaciones catalíticas.
Objetivo del estudio:
- Para dilucidar el mecanismo de reacción de NO-Fe (TPP) con bajas presiones de gas NO.
- Identificar los intermediarios clave y sus roles en los procesos de transformación.
- Investigar el potencial para la producción catalítica de óxido nitroso (N2O).
Principales métodos:
- El análisis espectroscópico, incluida la espectroscopia IR, se utilizó para identificar los intermediarios transitorios.
- Se emplearon experimentos de etiquetado de isótopos (14N/15N) para rastrear la transferencia y el acoplamiento de átomos.
- Se desarrollaron estudios cinéticos y propuestas mecanicistas basadas en observaciones experimentales.
Principales resultados:
- Se identificó un intermediario de adducto N-N-acoplado (NO) 2 transitorio.
- Se observó la formación de NO ((NO2) Fe ((TPP), lo que sugiere una vía que implica el NO2 libre.
- La producción catalítica de N2O se logró mediante el uso de un aceptor de átomos de oxígeno competitivo (PPh3).
- Los experimentos de etiquetado cruzado confirmaron la equivalencia de los átomos de oxígeno en el intermediario.
- La espectroscopia de infrarrojos confirmó bandas transitorias sensibles a los isótopos que son indicativas del intermediario.
Conclusiones:
- La reacción se lleva a cabo a través de un adyucto intermedio N-N acoplado.
- Un mecanismo propuesto explica la formación de nitrito y N2O.
- La transferencia de átomos de oxígeno desde el intermediario es eficiente e implica átomos de oxígeno equivalentes.
- El estudio proporciona información sobre la reactividad de NO-Fe (TPP) y los potenciales ciclos catalíticos.
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