Measurement of Silver−π Interactions in Solution Using Molecular Torsion Balances

A new series of molecular torsion balances were designed to measure the strength of individual Ag−π interactions in solution for an Ag­(I) coordinated to a pyridine nitrogen. The formation of a well-defined intramolecular Ag−π interaction in these model systems was verified by X-ray crystallography and 1H NMR. The strength of the intramolecular Ag−π interaction in solution was found to be stabilizing in nature and quantified to be −1.34 to −2.63 kcal/mol using a double mutant cycle analysis. The Ag−π interaction was also found to be very sensitive to changes in geometry or solvent environment.