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Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
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Respuesta al comentario sobre "Siguiendo la movilidad molecular durante las reacciones químicas: no hay evidencia de
Lucy L Fillbrook1, Jan-Philipp Günther2, Günter Majer2
1School of Chemistry, UNSW Sydney, Sydney, NSW 2052, Australia.
Journal of the American Chemical Society
|August 3, 2022
Resumen
Este estudio aborda las observaciones sobre las mediciones de RMN de difusión durante las reacciones de cicloadición azida-alquina catalizadas por cobre (CuAAC). Los investigadores confirman que no se observó ninguna mejora de la difusión para ninguna especie, validando sus hallazgos originales.
Área de la Ciencia:
- La cinética química
- Espectroscopia de resonancia magnética nuclear (RMN)
- Química supramolecular
Sus antecedentes:
- La RMN de difusión es una técnica poderosa para estudiar el movimiento molecular.
- La cicloadición azida-alquina catalizada por cobre (CuAAC) es una reacción de "clic" ampliamente utilizada en química.
- Estudios anteriores han reportado mejoras en la difusión durante las reacciones CuAAC, lo que ha llevado a una mayor investigación.
Objetivo del estudio:
- Responder a las observaciones relativas a las mediciones de RMN de difusión durante las reacciones CuAAC.
- Para aclarar que no se observó aumento de la difusión en ninguna especie.
- Validar la metodología y las conclusiones de publicaciones anteriores.
Principales métodos:
- Se utilizó la espectroscopia de RMN por difusión ordenada (DOSY) para controlar la difusión molecular.
- Se utiliza hidrazina como agente reductor para eliminar la superposición de picos.
- Investigó el efecto de los agentes de relajación, la longitud del pulso de gradiente y el tiempo de difusión en los coeficientes de difusión.
Principales resultados:
- No se observó aumento de la difusión en ninguna especie durante la reacción CuAAC.
- El agente de relajación no interfirió con la cinética de la reacción ni con la difusión molecular.
- La longitud del pulso gradiente y el tiempo de difusión no afectaron los coeficientes de difusión medidos.
- La superposición de picos se resolvió con éxito utilizando hidrazina.
Conclusiones:
- Los coeficientes de difusión observados son precisos y fiables.
- El supuesto de estado estacionario no es aplicable a las mediciones de difusión larga.
- Los hallazgos apoyan las conclusiones originales sobre la ausencia de mejora de la difusión en las reacciones CuAAC.
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