Fluoride binding in water with the use of micellar nanodevices based on salophen complexes.

Flore Keymeulen,Antonella Dalla Cort,Paolo De Bernardin,Luciano Galantini,Kristin Bartik,Ilaria Giannicchi

doi:10.1039/c4ob02298j

Abstract

The use of micelles to transpose lipophilic receptors, such as uranyl-salophen complexes, into an aqueous environment is a valuable and versatile tool. Receptor 1 incorporated into CTABr micelles forms a supramolecular system that exhibits excellent binding properties towards fluoride in water, despite the competition of the aqueous medium. To fully evaluate the potential of micellar nanodevices, we extended our previous study to other types of surfactants and to a uranyl-salophen receptor with a more extended aromatic surface. Paramagnetic relaxation enhancement experiments were used to obtain information on the location of the two receptors within the micelles and complementary information was obtained from dynamic light scattering experiments. With these data it is possible to account for the key factors necessary to obtain an efficient supramolecular device for anion binding in water.

Highlights

Anion recognition by artificial receptors that operate in aqueous solution is a field that has been growing exponentially in the last few decades due to the biological and environmental significance of these species
We have recently reported that Receptor 1, which is synthesized through the one-pot reaction of 1,2-phenylenediamine with two moles of salicylaldehyde in the presence of
The changes in the spectra triggered by the addition of increasing amounts of KF were sufficient to allow a precise assessment of the binding affinity

Summary

Introduction

Anion recognition by artificial receptors that operate in aqueous solution is a field that has been growing exponentially in the last few decades due to the biological and environmental significance of these species. The affinity of the systems for fluoride was investigated by UV-vis or NMR titrations and their structural characteristics were probed via NMR Paramagnetic Relaxation Enhancement (PRE) experiments, with the aim of correlating binding efficiency to the location of the receptors in the micelles.

Results

Conclusion