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Estudios espectroscópicos y electrónicos de la estructura de los complejos de fenolato Cu(II): orientación y
Somdatta Ghosh1, Jordi Cirera, Michael A Vance
1Department of Chemistry, Stanford University, Stanford, California 94305, USA.
Journal of the American Chemical Society
|November 13, 2008
Resumen
Los complejos de cobre-fenolato exhiben estructuras electrónicas distintas que influyen en su reactividad con el oxígeno. Se favorece una vía de oxidación de dos electrones sobre la transferencia de carga de ligando a metal para la activación del oxígeno.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Química computacional es la química computacional.
- La bioquímica es la bioquímica.
Sus antecedentes:
- Los complejos de cobre-fenolato son cruciales en los sistemas biológicos.
- Comprender su estructura electrónica es clave para dilucidar los mecanismos de reacción.
Objetivo del estudio:
- Para definir las estructuras electrónicas de dos complejos distintos de Cu (II) -fenolato.
- Para investigar su reactividad con el oxígeno utilizando métodos computacionales.
- Para explorar la relevancia de la biogénesis de la topa quinona en la amina oxidasa.
Principales métodos:
- Combinación de técnicas espectroscópicas (por ejemplo, EPR, UV-Vis).
- Cálculos de la Teoría Funcional de la Densidad (DFT).
- Análisis de las estructuras cristalográficas definidas de Cu (II) -fenolato.
Principales resultados:
- Se observaron distintas estructuras electrónicas e interacciones de enlace debido a la orientación del anillo de fenolato.
- Los cálculos de DFT revelaron diferencias significativas en la reactividad del oxígeno.
- La activación del oxígeno a través de la transferencia de carga de ligando a metal es energéticamente desfavorable.
- Una oxidación de dos electrones del fenolato a un complejo puente Cu(II) peroxoquinona es más favorable.
Conclusiones:
- La estructura electrónica dicta la reactividad de los complejos Cu(II) -fenolato con el oxígeno.
- La vía favorecida implica una oxidación de dos electrones del ligando fenolato.
- Este mecanismo proporciona información sobre la biogénesis de la topa quinona en las amino-oxidasas.
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