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Adición de triflato de metilo a un complejo de dinitrógeno de hafnoceno: metilación y conversión paso a paso n(2) a
Donald J Knobloch1, David Benito-Garagorri, Wesley H Bernskoetter
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York, 14853, USA.
Journal of the American Chemical Society
|September 30, 2009
Resumen
Los complejos de hafnoceno con ligandos de dinitrógeno reaccionan con el triflato de metilo para formar compuestos de metil diazenuro. Una reacción posterior produce complejos raros de hidrazonato, lo que demuestra nuevas vías para la funcionalización del dinitrógeno.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Química Inorgánica La Química Inorgánica es la química inorgánica.
Sus antecedentes:
- El dinitrógeno (N2) es una molécula estable, por lo que su activación y funcionalización es un desafío significativo en la química.
- Se sabe que los complejos de hafnoceno y zirconoceno coordinan los ligandos de dinitrógeno, ofreciendo plataformas potenciales para las transformaciones de N2.
Objetivo del estudio:
- Para investigar la reactividad de un complejo de dinitrógeno de hafnoceno con triflato de metilo.
- Explorar el potencial para la formación de enlaces C-N en el ligando coordinado de dinitrógeno.
- Para caracterizar los productos metilados resultantes y sus transformaciones posteriores.
Principales métodos:
- Síntesis y caracterización del complejo de dinitrógeno hafnoceno.
- Reacción del complejo de hafnoceno con el triflato de metilo.
- Análisis espectroscópico (NMR, cristalografía de rayos X) para identificar los productos.
- Estudios de etiquetado isotópico para elucidar los mecanismos de reacción.
Principales resultados:
- El tratamiento del complejo de dinitrógeno de hafnoceno con triflato de metilo produjo un complejo de hafnoceno de metil diazenuro, (eta(5)-C(5)Me(4)H)(2)Hf(OTf)(N(2)(CH(3))).
- Esta reactividad contrasta con el complejo de zirconoceno análogo, que no forma enlaces N-C en condiciones similares.
- Otra reacción del complejo de metil diazenido con metil triflato condujo a la formación de un raro complejo de hafnoceno hidrazonato a través de una segunda formación de enlace N-C, acompañada de pérdida de metano.
Conclusiones:
- El triflato de metilo puede metilizar eficazmente el ligando coordinado de dinitrógeno en los complejos de hafnoceno, formando especies de metil diazenuro.
- El complejo de hafnoceno metil diazenido sirve como precursor para una mayor funcionalización, lo que lleva a complejos raros de hidrazonato.
- La reactividad observada pone de relieve una vía distinta para la activación y la funcionalización del dinitrógeno en la química del hafnoceno en comparación con los análogos del zirconoceno.
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