Abstract

CUETARA-GUADARRAMA, Fabián; RAMIREZ-GUALITO, Karla  and  CUEVAS, Gabriel. Study of CH/π Interactions in the Molecular Recognition between Acetyl Galactopyranoside and 6-substituted 2-Methoxypyridines and 2(1H)-Pyridones. J. Mex. Chem. Soc [online]. 2017, vol.61, n.3, pp.205-216. ISSN 1870-249X.

A series of 6-substituted 2-methoxypyridine and 2(1H)-pyridones was designed and synthesized for its evaluation in the molecular recognition of acetyl 2,3,4,6-tetra-O-methyl-β-D-galactopyranoside substrate. 1H-NMR titration (affinity constant K a determination) and chemical shift perturbation experiments were performed to evaluate the capacity of these receptors to form CH/π interactions with the substrate. The addition of 2-methoxypyridines to the substrate effected up-field shift for the H3, H4 and H5 proton signals and down-field shift for the H2 proton signal of galactopyranoside substrate. The determined affinity constant K a values for the association between 2(1H)-pyridones and galactopyranoside showed that molecular recognition was weak. These results have demonstrated the existence of weak CH/π interactions and have reflected their weak intermolecular nature. Finally DFT calculations were performed to illustrate the geometry of the molecular recognition between 2(1H)-pyridones and galactopyranoside.

Keywords : CH/π interactions; supramolecular chemistry; glycosides; non-covalent interactions; molecular recognition.

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