Heterochiral Self-Discrimination Driven Dimerization of Polynuclear Gold(I)-Sulfido Complexes with Enhanced Phosphorescence

Decanuclear chiral gold(I) sulfido clusters (S^SDP-Au₁₀ and R^SDP-Au₁₀) have been assembled by taking advantage of the judiciously selected SDP ligands (SDP = 7,7'-bis(diphenylphosphino)-1,1'-spirobiindane). Interestingly, an achiral heterodimer icosanuclear meso-cluster (meso^SDP-Au₂₀) has been obtained by simply mixing S^SDP-Au₁₀ and R^SDP-Au₁₀ in a 1:1 ratio. These gold(I) complexes have been found to display intense near-infrared (NIR) luminescence with an emission maximum at around 750 nm in the solid state. The photoluminescence quantum yield (PLQY) of meso^SDP-Au₂₀ in drop-cast solid-state thin film has been found to show a significant enhancement from 8 % in the S^SDP-Au₁₀ and R^SDP-Au₁₀ to 25 %. In addition, the dimerization process with heterochiral self-discrimination has been found to be sensitive to the solvent polarity and configuration of the diphosphine ligand. This work has provided a platform for the investigation and mechanistic understanding of heterochiral self-sorting and assembly processes.