Tuning the Luminescent Properties of a Ag/Au Tetranuclear Complex Featuring Metallophilic Interactions via Solvent-Dependent Structural Isomerization

In this paper the reaction products of the basic gold­(I) species [Au­(C6Cl5)2]− against the acid salt Ag­(OClO3) in the presence of the S-donor macrocyclic ligand 1,4,7-trithiacyclononane ([9]­aneS3) are studied in different solvents. Two different isomers of stoichiometry [{Au­(C6Cl5)2}­Ag­([9]­aneS3)]2 were isolated depending on the solvent used, dichloromethane or tetrahydrofuran, which show different luminescence in the solid state. X-ray diffraction studies of these compounds reveals that both show the same heteropolynuclear Ag···Au···Au···Ag system but with different Au···Au interaction distances and different relative positions of the cationic fragment [Ag([9]­aneS3)]+ in the structure with respect the bimetallic Au···Au core. This work includes a study of the optical properties of both isomers, as well as time-dependent density functional theory calculations that were performed to determine the origin of their different luminescence.