Assembly of Luminescent Chiral Gold(I)-Sulfido Clusters via Chiral Self-Sorting

Due to the ubiquity of chirality in nature, chiral self-assembly involving self-sorting behaviors has remained as one of the most important research topics of interests. Herein, starting from a racemic mixture of SEG-based (SEG=SEGPHOS) chlorogold(I) precursors, a unique chiral butterfly-shape hexadecanuclear gold(I) cluster (Au-16) with different ratios of R-SEG and S-SEG ligands is obtained via homoleptic and heterochiral self-sorting. More interestingly, by employing different chlorogold(I) precursors of opposite chirality (such as R-SEG-Au-2 and S-BIN-Au-2 (BIN=BINAP)), an unprecedented heteroleptic and heterochiral self-sorting strategy has been developed to give a series of heteroleptic chiral decanuclear gold(I) clusters (Au10) with propellor-shape structures. Heterochiral and heteroleptic self-sorting have also been observed between enantiomers of homoleptic chiral Au-10 clusters to result in the heteroleptic chiral Au-10 clusters via cluster-to-cluster transformation. Incorporation of heteroleptic ligands is found to decrease the symmetry from S-4 of homoleptic meso Au-10 to C-2 of heteroleptic chiral Au-10 clusters. The chirality has been transferred from the axial chiral ligands and stored in the heteroleptic gold(I) clusters. The full potential of the chiral self-sorting in gold(I)-sulfido cluster system has been explored for the first time. Different combinations of axial chiral ligands give rise to distinct chiral gold(I)-sulfido clusters through different types of chiral self-assembly and self-sorting processes, evolving from homochiral assembly to heterochiral self-sorting and the unprecedented heterochiral and heteroleptic self-sorting.image