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Updated: Jul 7, 2026

Single-Molecule Diffusion and Assembly on Polymer-Crowded Lipid Membranes
Published on: July 19, 2022
Diffusion of a highly charged supramolecular assembly: direct observation of ion association in water
Michael D Pluth1, Bryan E F Tiedemann, Herman van Halbeek
1Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
Abstract:
The diffusion coefficient of the self-assembled supramolecular cluster [Ga4L6]12- depends on the cationic counterions in solution. Diffusion coefficients were determined using the pulsed-gradient spin-echo 1H NMR method and fit using nonlinear least-squares refinement. Saturation studies revealed a small number of ion-association sites on the exterior of the assembly and the direct observation of ion association in water. The addition of excess alkali-metal cations displaces the ion-associated hydrophobic tetra-alkyl-ammonium cations. Comparisons between tetraethyl- and tetra-propyl-ammonium show a preference for ion association with the more hydrophobic cation.
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