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.