Metallophilic and Inter-Ligand Interactions in Diargentous Compounds Bound by a Geometrically Flexible Macrocycle

A series of mono- and di-nuclear Ag-I complexes supported by a flexible macrocyclic ligand are reported. The geometric flexibility of the ligand was found to allow for a range of Ag-Ag interactions in the disilver complexes, depending on the identities of both the ancillary ligand and the counterion. Studies of the solution-phase dynamic exchange processes for these latter complexes found rapid interconversion through a mechanism that retained the multi-nuclearity. Quantum Theory of Atoms in Molecules (QTAIM) and Independent Gradient Model based on Hirshfeld partition (IGMH) analyses are used to evaluate the d(10)-d(10) interactions between silver centers in the various geometries observed for the solid-state structures of these complexes, revealing nearly identical Ag-Ag interactions, regardless of the relative geometries of the Ag centers. Instead, a weak, but non-negligible, inter-ligand interaction between two isocyanide units may contribute to the folded-ligand geometry observed in the solid state.