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Determinación de orientaciones moleculares en materiales desordenados desde el dicroísmo lineal de rayos X en el
Benjamin A Palmer1, Stephen P Collins2, Jürg Hulliger3
1Department of Structural Biology, Weizmann Institute of Science , Rehovot 760001, Israel.
Journal of the American Chemical Society
|December 10, 2016
Resumen
El dicroísmo lineal de rayos X en el borde L1 de yodo determinó con éxito las orientaciones de enlaces C-I en sólidos moleculares desordenados. Este método ofrece una nueva forma de estudiar los arreglos moleculares en materiales parcialmente ordenados.
Área de la Ciencia:
- Ciencias de los materiales
- Física del estado sólido
- Espectroscopia
Sus antecedentes:
- La determinación de las orientaciones de los enlaces moleculares es crucial para comprender las propiedades de los materiales.
- Las técnicas de difracción son limitadas en el análisis de materiales desordenados o parcialmente ordenados.
Objetivo del estudio:
- Demostrar la eficacia del dicroísmo lineal de rayos X (XLD) para determinar las orientaciones de los enlaces en materiales desordenados.
- Informar de la primera observación de XLD en el borde L1 de yodo.
Principales métodos:
- Estudió un compuesto de inclusión con moléculas de 4,4'-diodobifenilo invitadas desordenadas en un huésped de perhidrotrifenileno.
- Se registraron espectros de absorción de rayos X de borde L1 de yodo en varias orientaciones cristalinas.
- Analizó el dicroísmo de rayos X observado en el borde L1, comparándolo con los bordes L2 y L3.
Principales resultados:
- Se observó un dicroísmo de rayos X significativo en el borde L1 de yodo.
- No se detectó dicroísmo en los bordes L2 y L3 de yodo.
- El análisis cuantitativo del dicroísmo del borde L1 estableció con éxito las orientaciones de los enlaces C-I.
Conclusiones:
- El dicroísmo lineal de rayos X en el borde L1 de yodo es efectivo para determinar las orientaciones de enlaces en materiales desordenados.
- Esta técnica proporciona información donde los métodos de difracción fallan.
- Los hallazgos permiten el estudio de las orientaciones moleculares en cristales líquidos, líquidos confinados y fases cristalinas desordenadas.
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