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Medidas de distancias internucleares (31) P-(51) V en sólidos polioxoaniónicos utilizando espectroscopia de RMN de

Wenlin Huang¹, Alexander J Vega, Terry Gullion

¹Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.

Journal of the American Chemical Society

|October 9, 2007

Resumen

Los experimentos REAPDOR (Rotational Echo Adiabatic Passage Double Resonance) miden con precisión las distancias entre los núcleos de fósforo-31 (31P) y de vanadio-51 (51V) en los sólidos. Esta técnica ofrece un método sensible para las mediciones de distancias interatómicas, particularmente en materiales desordenados.

Área de la Ciencia:

Espectroscopia de RMN en estado sólido.
Ciencia de los materiales ciencia de los materiales.
Química inorgánica y inorgánica.

Sus antecedentes:

Las mediciones precisas de distancias interatómicas son cruciales para comprender las propiedades de los materiales.
Los métodos tradicionales pueden estar limitados en sólidos amorfos o microcristalinos.
Los pares de espín nuclear como el 31P y el 51V ofrecen manijas espectroscópicas únicas.

Objetivo del estudio:

Establecer y validar la doble resonancia de paso adiabático de eco rotacional (REAPDOR) para mediciones cuantitativas de distancia.
Para medir las distancias 31P-51V en sólidos polioxoaniónicos específicos sustituidos por vanadio.
Para evaluar la aplicabilidad de REAPDOR en ausencia de una orden de largo alcance.

Principales métodos:

Ejecución de los experimentos REAPDOR en núcleos de spin-1/2 (31P) y spin-7/2 (51V).
Medida cuantitativa de las distancias 31P-51V en K4PVW11O40, 1-K7P2VW17O62 y 4-K7P2VW17O62.
Comparación de las distancias derivadas de REAPDOR con los datos de difracción de rayos X a través de simulaciones numéricas.

Principales resultados:

Establecimiento exitoso de REAPDOR para la determinación precisa de la distancia 31P-51V.
Medidas cuantitativas de las distancias P-V en los sólidos polioxoaniónicos estudiados.
Excelente acuerdo entre los datos de REAPDOR y los resultados de difracción de rayos X.

Conclusiones:

La espectroscopia REAPDOR es una sonda altamente sensible y precisa para las distancias interatómicas P-V.
La técnica es particularmente valiosa para las mediciones de distancia en materiales que carecen de orden de largo alcance.
REAPDOR muestra un amplio potencial para las mediciones de distancias interatómicas en otros sistemas de espín nuclear spin-7/2-spin-1/2.

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