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Hyperpolarized Xenon for NMR and MRI Applications
Published on: September 6, 2012
Un complejo hidrosoluble Xe@cryptophane-111 exhibe una estabilidad termodinámica muy alta y un peculiar
Robert M Fairchild1, Akil I Joseph, K Travis Holman
1Department of Chemistry, Georgetown University, Washington, DC 20057, USA.
Journal of the American Chemical Society
|October 21, 2010
Resumen
Los investigadores desarrollaron un derivado hidrosoluble de criptofano-111 con seis fracciones de rutenio, creando un nuevo huésped para el xenón. Este nuevo compuesto muestra una alta afinidad con el xenón en el agua, ampliando las posibilidades para aplicaciones de unión de xenón.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- Ciencia de los materiales Ciencia de los materiales.
- Espectroscopia de resonancia magnética nuclear Espectroscopia de resonancia magnética nuclear Espectroscopia de resonancia magnética nuclear Espectroscopia de resonancia magnética nuclear Espectroscopia de resonancia magnética nuclear
Sus antecedentes:
- Cryptophane-111 es un conocido huésped que se une al xenón.
- La funcionalización de las moléculas del huésped es clave para adaptar sus propiedades.
- La solubilidad en agua es una característica deseable para muchas aplicaciones químicas.
Objetivo del estudio:
- Para sintetizar el primer derivado hidrosoluble del criptofano 111.
- Para investigar las propiedades de unión al xenón de este nuevo derivado en solución acuosa.
- Explorar el potencial de este nuevo huésped para ampliar la utilidad de la espectroscopia de RMN de xenón.
Principales métodos:
- Síntesis química y funcionalización del criptofano-111 con las fracciones de rutenio.
- Espectroscopia de RMN hiperpolarizada (129) Xe para medir la afinidad de unión al xenón.
- Difracción de rayos X de cristal único para determinar las propiedades estructurales.
Principales resultados:
- Síntesis exitosa de un derivado hidrosoluble del criptofano-111, [(Cp*Ru) ((6) 1) Cl ((6), con un rendimiento del 89%.
- Se ha demostrado una alta afinidad por el xenón en el agua, con una constante de unión de 2.9{\displaystyle 2.9}2) × 10{\displaystyle 10}4) M{\displaystyle M}-1).
- Significativo desplazamiento hacia abajo en el desplazamiento químico de la RMN (129) Xee para especies acuosas Xe@[2](6+), ampliando el rango de desplazamiento químico observable.
Conclusiones:
- El nuevo derivado de criptofano soluble en agua es un huésped eficaz para el xenón en ambientes acuosos.
- El criptofano funcionalizado mejora significativamente el rango de desplazamiento químico para la RMN de xenón.
- El estudio demuestra la adaptabilidad del núcleo cryptophane-111 para la unión de invitados.
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