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Síntesis, estructura y reactividad de un carbeno de calcio estabilizado: R(2)CCa
Lars Orzechowski1, Georg Jansen, Sjoerd Harder
1Department of Chemistry, University Duisburg-Essen, Universitätsstrasse 5-7, 45117 Essen, Germany.
Journal of the American Chemical Society
|November 9, 2006
Resumen
Se sintetizaron los complejos de calcio de un ligando de bis ((iminophosphorano) metano. El ligando dianiónico resultante, con carga concentrada en el carbono central, forma aductos estables con los compuestos carbonilo y se somete a reacciones de cicloadición.
Área de la Ciencia:
- Química organometálica Química orgánica de los metales.
- Coordinación Química de la Coordinación
- Grupo Principal Química.
Sus antecedentes:
- Los ligandos de bis (iminofosforano) metano ofrecen posibilidades únicas de coordinación.
- Los complejos de calcio son de interés debido a su reactividad y aplicaciones potenciales.
Objetivo del estudio:
- Para sintetizar y caracterizar los nuevos complejos de calcio del ligando bis (((iminophosphorano) metano.
- Para investigar la estructura electrónica y la reactividad de estos complejos de calcio.
Principales métodos:
- Deprotonación del ligando utilizando amida de calcio y dibenzilcalcio.
- Difracción de rayos X para la determinación de la estructura cristalina.
- Análisis computacional de las cargas atómicas y de grupo.
Principales resultados:
- La mono-deprotonación se produjo con la amida de calcio, mientras que el dibenzilcalcio produjo la deseada desprotonación de 2 veces.
- El ligando dianiónico ([4-Ca](2) exhibe una densidad de carga negativa significativa en el átomo de carbono central.
- Se formaron aductos estables con la benzofenona y el adamantilcianuro.
- Una reacción de [2+2]-cicloadición con ciclohexilisocianato produjo un nuevo ligando tetradentado.
Conclusiones:
- La carga negativa en el ligando desprotonado se encuentra principalmente en el carbono central.
- Los complejos de calcio de este ligando muestran una notable estabilidad y reactividad hacia los electrófilos.
- El ligando puede sufrir diversas reacciones, incluida la formación de adyuctos y la cicloadición.
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