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La reacción de las cobaloximas con el hidrógeno: productos y termodinámica
Deven P Estes1, David C Grills, Jack R Norton
1Department of Chemistry, Columbia University , 3000 Broadway, New York, New York 10027, United States.
Journal of the American Chemical Society
|November 27, 2014
Resumen
Los investigadores observaron un intermedio de hidruro de cobalto utilizando espectroscopia UV-vis bajo alta presión de hidrógeno. Caracterizaron un nuevo compuesto de cobalto, determinando su energía libre de disociación de enlaces O-H y pK a).
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Química organometálica Química orgánica de los metales.
- La espectroscopia es una técnica de espectroscopia.
Sus antecedentes:
- Los hidratos de cobalto se proponen como intermediarios en reacciones que involucran el sistema Co ((dmgBF2) 2L2.
- La observación directa de estos productos intermedios de hidruro de cobalto ha sido un desafío.
- La comprensión de estos intermedios es crucial para las aplicaciones catalíticas.
Objetivo del estudio:
- Para observar directamente y caracterizar los intermediarios de hidruro de cobalto.
- Para investigar las propiedades de un compuesto de cobalto (I) recién formado.
- Para determinar la energía libre de disociación del enlace y pK (a) del enlace O-H en el nuevo compuesto.
Principales métodos:
- Se empleó espectroscopia UV-vis para monitorear las reacciones.
- Las reacciones se llevaron a cabo bajo altas presiones de hidrógeno (hasta 70 atm) en acetonitrilo.
- Se analizaron datos espectroscópicos para identificar y cuantificar las especies de cobalto.
Principales resultados:
- Se registraron con éxito los espectros UV-vis de Co ((dmgBF2) 2L2 (1) bajo alta presión de hidrógeno.
- Se formó y se observó un compuesto de cobalto (6a) con un protón intercambiable.
- La energía libre de disociación del enlace (50,5 kcal/mol) y pK (a) (13,4) del nuevo enlace O-H en 6a se determinaron en acetonitrilo.
Conclusiones:
- Se obtuvo evidencia espectroscópica directa de un intermediario de hidruro de cobalto.
- Se caracterizó una nueva especie de hidruro de cobalto, proporcionando información sobre la química del hidruro de cobalto.
- Las propiedades termodinámicas determinadas del enlace OH se alinean con los informes anteriores, validando los hallazgos.
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