Self-Assembly of Mechanoluminochromic Ladder-Shaped Gold(I) Clusters Promoted Using Cooperative Aurophilicity

The self-assembly of mechanoluminochromic polynuclear gold(I) complexes has attracted more and more attention in the field of supramolecular gold(I) chemistry. In this work, we adopted a stepwise self-assembly strategy to precisely synthesize two polynuclear gold(I) supramolecular clusters. Through cooperative AuI center dot center dot center dot Au-I and Au-N interactions, the gold(I) clusters 1(+)center dot BF4- and 2(4+)center dot 4BF(4)(-) with Au4 and Au16 cores, respectively, were successfully constructed. In these supramolecular clusters, (dppm)Au(2)Cl(2 )coordination motifs and trithiocyanuric linkers were stepwise assembled via sequential thiolate-chloride/phosphine coordination substitution and Au-S/Au-N coordination bond rearrangement. Two well-defined gold(I) supramolecular clusters displayed intense emission both in the solid state and in solution. Furthermore, the ladder-shaped cluster 2(4+)center dot 4BF(4)(- )exhibited reversible mechanochromic luminescence behavior in the solid state as well as aggregation-caused redshifted emission in solution. Upon mechanical grinding, the emission of the cluster 2(4+)center dot 4BF(4)(-) changed from yellow at 582 nm to red at 612 nm. The initial emission could be fully recovered by treatment with acetonitrile.

Automated summary

The self-assembly of mechanoluminochromic polynuclear gold(I) complexes has attracted increasing attention in the field of supramolecular gold(I) chemistry. In this study, two polynuclear gold(I) supramolecular clusters with Au4 and Au16 cores were successfully constructed through cooperative interactions. One of the clusters exhibited intense emission in both the solid state and in solution, while the other cluster showed reversible mechanochromic luminescence behavior in the solid state.