Synthesis of Highly Stable CdSe Magic-Size Clusters Displaying Optical Absorption Peaking at 272 Nm

We report the transformation from CdSe magic-size clusters (MSCs, including those displaying optical absorption peaking at ∼360 nm (MSC-360) and at ∼390 nm (MSC-391) to MSC-272. In the presence of diphenylphosphine (DPP) and a Cd salt (such as Cd(OcA)₂), the absorption peaks at 360 and 390 nm of the reactant MSCs disappeared, while that at 272 nm developed. We attribute the 272 nm peak to MSC-272, which has not been reported previously. For the transformation pathway, we suggest that the reactant MSCs become two parts, A (CdSe reactive species) and B (activated selenium anions Se^2-); Part B then transforms to SeDPP. Ultimately, MSC-272 develops from the reaction of A + SeDPP + Cd(OcA)₂. Various cadmium salts of carboxylates and phosphonates are able to synthesize MSC-272 that is stable even at 300°C. Our study paves the way to novel MSCs, together with a fundamental CdSe MSCs, Ligand-Induced Transformation, Low Temperature Synthesis, Solvent Dispersibility, Thermal stabilityunderstanding of the cluster transformation.