Coordination of Quantum Dots in a Polar Solvent by Small-Molecule Imidazole Ligands

ABSTRACT: Colloidal quantum dots (QDs) are attractive fluorophores for bioimaging and biomedical applications because of their favorable and tunable optoelectronic properties. In this study, the native hydrophobic ligand environment of oleate-capped sphalerite CdSe/ZnS core/shell QDs was quantitatively exchanged with a set of imidazole-bearing small-molecule ligands. Inductively coupled plasma-optical emission spectroscopy and 1H NMR were used to identify and quantify three different ligand exchange processes: Z-type dissociation of the Zn(oleate)2, L-type association of the imidazole, and X-type anionic exchange of oleate with Cl-, all of which contributed to the overall ligand exchange.

Automated summary

In this study, a quantitative ligand exchange was performed on oleate-capped CdSe/ZnS quantum dots using imidazole ligands, and different reaction mechanisms were identified and quantified using various analytical methods.