Protonation and anion-binding properties of aromatic sulfonylurea derivatives.
RSC Adv
; 11(39): 23992-24000, 2021 Jul 06.
Article
em En
| MEDLINE
| ID: mdl-35479025
ABSTRACT
In this work the anion-binding properties of three aromatic sulfonylurea derivatives in acetonitrile and dimethyl sulfoxide were explored by means of NMR titrations. It was found that the studied receptors effectively bind anions of low basicity (Cl-, Br-, I-, NO3 - and HSO4 -). The stoichiometry of the complexes with receptors containing one binding site was 1 1 exclusively, whereas in the case of the receptor containing two sulfonylurea groups 1 2 (receptor anion) complexes were also detected in some cases. The presence of strongly basic anions (acetate and dihydrogen phosphate) led to the deprotonation of the sulfonylurea moiety. This completely hindered its anion-binding properties in DMSO and only proton transfer occurred upon the addition of basic anions to the studied receptors. In MeCN, a complex system of equilibria including both ligand deprotonation and anion binding was established. Since ionisation of receptors was proven to be a decisive factor defining the behaviour of the sulfonylurea receptors, their pK a values were determined using several deprotonation agents in both solvents. The results were interpreted in the context of receptor structures and solvent properties and applied for the identification of the interactions with basic anions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
RSC Adv
Ano de publicação:
2021
Tipo de documento:
Article