Molecular nanocluster analogues of CdSe/ZnSe and CdTe/ZnTe core/shell nanoparticles

Abstract

The ternary II–II′–VI nanoclusters [(N,N′-tmeda)5Zn5Cd11E13(EPh)6(thf)n] (1, E = Se, n = 2; 2, E = Te, n = 1) have been synthesized by the reaction of bis(trimethylsilylchalcogenolate)zinc(II) complexes in the presence of PhESiMe3 and solubilizing phosphine ligands. Structural characterization of the complexes by X-ray crystallography revealed that the clusters consist of CdE cores whose surfaces are stabilized by [(N,N′-tmeda)5ZnE2] units, and hence can be described as molecular analogues of core/shell nanoparticles. The optical properties of the clusters exhibit the effects of quantum confinement and are luminescent at room temperature with emission occurring near the absorption edge. Solid-state thermal decomposition of 1 and 2 results in the formation of ternary ZnCdE materials with the same metal stoichiometry as the cluster precursors.