An Unprecedented Luminescent Polynuclear Gold(I) μ₃-Sulfido Cluster With a Thiacrown-like Architecture

An unprecedented Au18 thiacrown directed by Au(I)···Au(I) interactions and supported by tridentate phosphine (dpepp) and μ3-sulfido ligands that highly resembles the 18-membered thiacrown ether [18]aneS6 in appearance has been synthesized. The sulfides of the Au3(μ3-S) units in the central cavity point toward each other and are located on the same plane, allowing them to bind the soft Ag+ ion with immediate and pronounced spectroscopic changes. Reversible binding and spectroscopic changes can be readily achieved upon addition of CH3CN without disruption of the Au18 macrocycle.