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Intercambio de metales y autoinclusión de cavitandas funcionales
Patrick Amrhein1, Alexander Shivanyuk, Darren W Johnson
1The Skaggs Institute for Chemical Biology and The Department of Chemistry, the Scripps Research Institute, MB-26, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
Journal of the American Chemical Society
|August 29, 2002
Resumen
Las nuevas cavitandas con grupos fosfonados pueden encapsular a los huéspedes como si fueran drogas. La adición de sales de lantánidos libera a los huéspedes, lo que permite aplicaciones de unión y liberación controladas.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- Síntesis orgánica La síntesis orgánica.
- Química entre anfitrión y huésped.
Sus antecedentes:
- Los cavitandos son anfitriones moleculares capaces de encapsular las moléculas invitadas.
- La funcionalización de los bordes de cavitand con grupos de ligación de metales mejora sus propiedades de unión.
- Comprender la dinámica huésped-huésped y los cambios conformacionales es crucial para diseñar sistemas de reconocimiento molecular.
Objetivo del estudio:
- Para sintetizar nuevos cavitandos funcionalizados con grupos de carboximetilfosfonato.
- Para investigar el comportamiento de complejación huésped-huésped de estos cavitandos con varios huéspedes.
- Para explorar la dinámica conformacional y los mecanismos de liberación de invitados desencadenados por los iones metálicos.
Principales métodos:
- Reacción de Arbuzov para la síntesis de cavitandos funcionalizados con fosfonatos.
- Difracción de rayos X monocristalino para determinar las estructuras en estado sólido.
- Espectroscopia de Resonancia Magnética Nuclear (RMN) para estudiar las conformaciones del estado de solución y la estabilidad compleja.
- Estudios de liberación de huéspedes inducida por iones de lantanuro.
Principales resultados:
- Síntesis de octafosfonato y difosfonato de cavitandos.
- Formación de caviplejos estables con los derivados del adamantano, la quinuclidina, las sales de amonio/fosfonio y el ibuprofeno.
- Observación de distintas conformaciones de jarrón y cometa influenciadas por el disolvente y los iones metálicos.
- Liberación cuantitativa del huésped tras la adición de triflato de lantanoide (La(OTf) ((3)).
- Interacciones metal-ligando que controlan el equilibrio de unión y liberación.
Conclusiones:
- Los cavitandos de fosfonato sintetizados exhiben versátiles capacidades de complejación huésped-invitado.
- La flexibilidad conformal de los cavitandos permite la unión y liberación controladas de los huéspedes.
- Los iones lantánidos actúan como desencadenantes para la expulsión de huéspedes, lo que demuestra el potencial de los materiales sensibles.
- El estudio proporciona información sobre el diseño de sistemas supramoleculares dinámicos para el reconocimiento y la entrega molecular.
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