A combination of proton spin diffusion NMR and molecular simulations to probe supramolecular assemblies of organic molecules in nanoporous materials

[EN] In this work we show the use of high-resolution H-1 MAS NMR to distinguish between two kinds of aggregation states of (1R,2S)-ephedrine, a chiral organic structure directing agent, occluded within AFI-type microporous aluminophosphates. We investigate in particular the supramolecular assembly o...

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Detalles Bibliográficos
Autores: Dib, Eddy, Bernardo Maestro, Beatriz, López Arbeloa, Fernando, Pérez Pariente, Joaquín, Gómez Hortigüela, Luis
Tipo de recurso: artículo
Fecha de publicación:2022
País:España
Institución:Universidad del País Vasco
Repositorio:Addi. Archivo Digital para la Docencia y la Investigación
OAI Identifier:oai:addi.ehu.eus:10810/56354
Acceso en línea:http://hdl.handle.net/10810/56354
Access Level:acceso abierto
Palabra clave:large-pore zeolite
solid-state nmr
structure directing agents
chemistry
crystallography
ephedrine
packing
powders
design
Descripción
Sumario:[EN] In this work we show the use of high-resolution H-1 MAS NMR to distinguish between two kinds of aggregation states of (1R,2S)-ephedrine, a chiral organic structure directing agent, occluded within AFI-type microporous aluminophosphates. We investigate in particular the supramolecular assembly of the molecules through pi MIDLINE HORIZONTAL ELLIPSIS pi type interactions of their aromatic rings when confined within the one-dimensional AFI channels. A series of high-resolution two-dimensional spin diffusion spectra combined with molecular simulations and DFT calculations allowed us to distinguish different aggregation states of ephedrine molecules and precisely estimate the distances between the aromatic rings and their closest protons inside the zeolite channels as a consequence of distinct proton spin diffusion profiles.