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Complejos catiónicos de metilo de escandio soportados por un marco de ligando beta-diketiminato ("Nacnac") ligando
Paul G Hayes1, Warren E Piers, Robert McDonald
1Department of Chemistry, University of Calgary, 2500 University Drive N.W., Calgary, Alberta, Canada.
Journal of the American Chemical Society
|March 7, 2002
Resumen
Un nuevo complejo de escandio forma cationes de alquilo de escandio altamente activos para la polimerización de etileno. Estos catalizadores, activados por borano, muestran un rendimiento comparable al de los sistemas de metaloceno del grupo 4.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Catálisis de polimerización por catálisis de polimerización.
- Complejos de escandio complejos de escandio
Sus antecedentes:
- Los voluminosos ligandos beta-diketiminados estabilizan los complejos metálicos libres de bases.
- Los ácidos de Lewis organometálicos como B ((C ((6) F ((5)) ((3)) son cruciales para la activación de los precursores de los metales.
Objetivo del estudio:
- Para sintetizar y caracterizar los cationes alquilo de escandio de un complejo de dimetilo escandio.
- Para investigar la actividad catalítica de estos complejos de escandio en la polimerización de etileno.
Principales métodos:
- Reacción de un complejo de dimetilscandio con B(C(6) F(5)) ((3).
- Caracterización espectroscópica (CMN) y cristalografía de rayos X. Caracterización espectroscópica (CMN) y cristalografía de rayos X.
- Experimentos de polimerización del etileno.
Principales resultados:
- Formación de un dimero monocationico mu-metil y un catión metil monomérico.
- Caracterización de una especie única de dicationic scandium.
- Alta actividad catalítica para la polimerización del etileno, acercándose a los sistemas de metaloceno del grupo 4.
Conclusiones:
- El complejo de dimetilo escandio libre de bases sirve como un precursor eficaz para los cationes de escandio catalíticamente activos.
- La actividad catalítica observada pone de relieve el potencial de los metales del grupo 3 en la polimerización de las olefinas.
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