Coordination Chemistry Laboratory, Department of Chemistry, Graduate School of Science, The University of Osaka
Metalloligand protected metal sulfide clusters
Metal oxides and metal sulfide in the nano regime are often called as nanocluster or quantum dots. These nanoclusters are known to exhibit unique optical properties which is dependent on their size, structure, or composition. Our group have successfully synthesized a large silver sulfide nanocluster showing optical activity through the reaction of an aminothiolato metalloligand, [Rh(aet)3], with silver ions and D-penicillamine.
The obtained silver sulfide nanocluster is protected by 14 metalloligand units and the overall nanocluster has a high charge of +20, rendering it soluble in water. Furthermore, the use of chiral D-penicillamine as the sulfide source also enable chirality transfer, making it an optically active silver sulfide nanocluster.
When the same reaction was conducted using [Ir(aet)3] instead of [Rh(aet)3], we successfully synthesized an analogous silver sulfide nanocluster which is emissive, whereas the rhodium metalloligand protected counterpart is non-emissive. In addition, upon reaction of the silver sulfide nanocluster with gold(I) or copper(I) ions, metal exchange reaction took place, affording unprecedented mixed-metal silver sulfide nanocluster accompanied with changes in emission wavelength and intensity.