Zinc chalcogenolate complexes as capping agents in the synthesis of ternary II-II'-VI nanoclusters: structure and photophysical properties of [(N,N'-tmeda)5Zn5Cd11Se13(SePh)6(thf)2

We report the synthesis of the complex (N,N'-tmeda)Zn(SeSiMe3)2 (1), whose pendant trimethylsilyl moieties result in a powerful reagent for the generation of ternary MM'E materials. Reaction of 1 with (PnPr3)2Cd(OAc)2 and PhSeSiMe3 has led to the formation of the ternary ZnCdSe nanocluster (N,N-tmeda)5Zn5Cd11Se13(SePh)6(thf)2] (2). The cluster consists of a CdSe core capped by ZnSe2 units, and represents the first example of a structurally characterized II-II'-VI nanocluster. Utilization of an analogous (trimethylsilyl)tellurolate precursor leads to the formation of (N,N-tmeda)5Zn5Cd11Te13(TePh)6(thf)] (3). The absorption spectra of 2 and 3 exhibit bands that have been assigned to "excitonic" transitions. The clusters are also luminescent at room temperature, exhibiting "band-edge" luminescence both in solution and in the solid state.