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.