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Construction and Systematical Symmetric Studies of a Series of Supramolecular Clusters with Binary or Ternary Ammonium Triphenylacetates
Published on: February 15, 2016
Localización de aminas protonadas en clatratos.
Terrence M Chang1, Richard J Cooper, Evan R Williams
1Department of Chemistry, University of California , Berkeley, California 94720-1460, United States.
Journal of the American Chemical Society
|September 7, 2013
Resumen
Se identificaron estructuras estables de amoníaco protonado hidratado y aminas con 20 moléculas de agua utilizando espectroscopia. Estos cúmulos de números mágicos exhiben estructuras similares a los clatratos, con la ubicación de los iones que influyen en la estabilidad y en la unión de hidrógeno.
Área de la Ciencia:
- Química Física es la química física.
- Física Química Física Química es la física de la química.
- La espectroscopia es una técnica de espectroscopia.
Sus antecedentes:
- Investigar la influencia de los iones en la red de enlaces de hidrógeno del agua es crucial.
- Comprender las estructuras de los iones hidratados proporciona información sobre la solvación y la actividad superficial.
Objetivo del estudio:
- Determinar las estructuras y estabilidades del amoníaco protonado hidratado y varias aminas.
- Para aclarar el papel del tipo de iones y el tamaño de los grupos de agua en la formación estructural.
Principales métodos:
- Espectroscopia de fotodisociación por infrarrojos (IRPD). espectroscopia de fotodisociación por infrarrojos.
- Espectroscopia de disociación por radiación infrarroja de cuerpo negro (BIRD) a 133 K.
- Comparación con los iones de referencia (Rb+, tert-butilamina protonada).
Principales resultados:
- Se observaron grupos de números mágicos (MNC) con 20 moléculas de agua para la mayoría de los iones, lo que indica estructuras estables similares a los clatratos.
- El tetrametilamonio y los grupos más pequeños/mayores mostraron estructuras no clatradas.
- El amoníaco protonado se encontró en el interior, mientras que la metil-protonada y la n-heptylamina estaban en la superficie del clatrato.
Conclusiones:
- El número y la orientación de los enlaces de hidrógeno, no solo la cantidad, dictan la estabilidad del cúmulo.
- Los hallazgos experimentales sirven como puntos de referencia para los estudios computacionales sobre las interacciones entre iones y agua.
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