Rhodium–silver superatomic nanoclusters stabilized by diselenophosphate ligands

Ligand replacement is an efficient and high-yield synthesis method that is valuable in constructing multifunctional nanoclusters. We report the first Rh/Ag alloy nanoclusters stabilized by selenium-based ligands, namely [RhH₂Ag₁₉{Se₂P(OⁱPr)₂}₁₂] (1), [RhHAg₂₀{Se₂P(OⁱPr)₂}₁₂] (2), and [RhAg₂₁{Se₂P(OⁱPr)₂}₁₂] (3). These nanoclusters were comprehensively characterized by UV-vis spectroscopy, photoluminescence, ESI mass spectrometry, X-ray crystallography and DFT analysis. The metal cores of these three nanoclusters closely resemble their sulfur analogs, with the primary distinction lying in the location of the peripheral capping silver atoms due to the difference in the bite distances of the S- and Se-chelates. Compared to their sulfur analogs, a significant red shift was observed in the absorption spectra of 1, 2, and 3, but a blue shift in the photoluminescence spectra.