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Pruebas de un enlace covalente significativo en el Au ((CN) ((2) ((-))
Xue-Bin Wang1, Yi-Lei Wang, Jie Yang
1Department of Physics, Washington State University, 2710 University Drive, Richland, Washington 99354, USA.
Journal of the American Chemical Society
|October 29, 2009
Resumen
Este estudio revela un enlace covalente significativo en los enlaces oro-carbono dentro del ion dicyanuro de oro (Au(CN) 2-). Los métodos experimentales y computacionales confirman este carácter covalente, lo que explica la notable estabilidad del compuesto.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Química Física es la química física.
- Química computacional es la química computacional.
Sus antecedentes:
- El ion dicyanuro de oro (Au(CN) 2-) es un compuesto de oro altamente estable.
- A pesar de su estabilidad, la naturaleza precisa de su enlace químico, particularmente el enlace Au-C, sigue siendo incompletamente entendida.
Objetivo del estudio:
- Proporcionar evidencia experimental directa para el carácter de enlace covalente en los enlaces Au-C de Au(CN)2-.
- Para dilucidar la estructura electrónica y la unión química en Au ((CN) 2 - a través de análisis espectroscópico y computacional.
- Para comparar la unión en Au(CN)2- con sus congéneres más ligeros, Ag(CN)2- y Cu(CN)2-.
Principales métodos:
- Espectroscopia de fotoelectrones con fotones de desprendimiento de 118 nm.
- Comparación experimental con el dicyanuro de plata (Ag(CN) 2-) y el dicyanuro de cobre (Cu(CN) 2-).
- Teoría funcional de la densidad (DFT) y cálculos ab initio de alto nivel.
Principales resultados:
- Observación de las progresiones vibratorias en el modo de estiramiento Au-C para todas las transiciones de desprendimiento en Au(CN)2-.
- Contrasta con las transiciones similares a las atómicas observadas para Cu(CN) 2-, destacando el enlace covalente en Au(CN) 2-.
- Información detallada de la estructura electrónica obtenida para Au(CN)2-.
Conclusiones:
- La evidencia experimental directa confirma el carácter covalente significativo en los enlaces Au-C de Au(CN)2-.
- Los efectos relativistas juegan un papel crucial en el fuerte enlace covalente observado en Au(CN)2-.
- La unión covalente identificada explica la excepcional estabilidad del ion dicyanuro de oro.
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