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La estabilización de la combinación de estado de oxidación elusivo de orto-quinona / cobre (I) a través de la
Sayak Roy1, Biprajit Sarkar, Denis Bubrin
1Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany.
Journal of the American Chemical Society
|October 29, 2008
Resumen
Este estudio identifica un nuevo complejo de cobre (I) con una ortoquinona no reducida, estabilizada por las interacciones pi/pi. Estas interacciones influyen en el cobre.
Área de la Ciencia:
- Coordinación Química de la Coordinación
- Química organometálica Química orgánica de los metales.
- Química supramolecular de las moléculas.
Sus antecedentes:
- Las ortoquinonas generalmente se reducen antes de la complejación.
- La estabilización de ortoquinonas no reducidas en complejos metálicos es un desafío.
- Comprender las interacciones no covalentes en los complejos metálicos es crucial.
Objetivo del estudio:
- Sintetizar y caracterizar un complejo de cobre (I) de una ortoquinona completamente no reducida.
- Investigar el papel de las interacciones pi/pi en la estabilización de este complejo.
- Explorar las propiedades electroquímicas y los productos de reducción del complejo.
Principales métodos:
- Cristalografía de rayos X monocristalino de un solo cristal.
- La espectroscopia de resonancia magnética nuclear (RMN) también se conoce como espectroscopia de resonancia magnética nuclear.
- Espectroscopia de infrarrojos (IR) para el infrarrojo.
- La espectroscopia UV-visible (UV-vis) es una técnica de espectroscopia de rayos UV.
- Cálculos de la Teoría Funcional de la Densidad (DFT, por sus siglas en inglés)
- Estudios electroquímicos en los estudios electroquímicos.
- La espectroscopia de resonancia paramagnética de electrones (EPR, por sus siglas en inglés) es una espectroscopia de resonancia paramagnética.
Principales resultados:
- Se sintetizó y caracterizó un complejo heterodinuclear de cobre (I), [PhenQ) Cu (dppf) ] (BF4), que presenta una ortoquinona (PhenQ) completamente no reducida.
- Los resultados cristalográficos y DFT indican que las interacciones fenil/PhenQ pi/pi intramoleculares estabilizan el complejo, con apilamiento intermolecular PhenQ/PhenQ pi también observado.
- Los cálculos de DFT revelaron que estas interacciones pi causan una geometría de coordinación distorsionada en Cu(I), evidenciada por diferentes longitudes de enlace Cu-O y Cu-P y una amplia gama de ángulos de enlace (99-133 grados).
- La reducción electroquímica a bajas temperaturas produjo una especie reversible de semiquinona-cobre, caracterizada por la espectroscopia EPR.
Conclusiones:
- El estudio sintetizó y caracterizó con éxito un nuevo complejo de cobre (I) con una ortoquinona no reducida estabilizada.
- Las interacciones intramoleculares pi/pi juegan un papel importante en la estabilización del esquisito arreglo orto-quinona e influyen en la geometría de coordinación.
- El complejo exhibe un interesante comportamiento electroquímico, formando una especie semiquinona-cobre al reducirse.
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