Multiple Evidence for Gold(I)⋅⋅⋅Silver(I) Interactions in Solution

Metallophilic Au⋅⋅⋅Ag interactions exist in concentrated solutions as well as in the 2D polymeric solid‐state structure of [AuAg 3 (C 6 F 5 )(CF 3 CO 2 ) 3 (CH 2 PPh 3 )] n (see picture for the asymmetric unit) according to EXAFS and pulsed‐gradient spin‐echo NMR spectroscopy measurements. Calculations support both the emission assignments and the existence of the metallophilic interactions in solution. magnified image [AuAg 3 (C 6 F 5 )(CF 3 CO 2 ) 3 (CH 2 PPh 3 )] n ( 2 ) was prepared by reaction of [Au(C 6 F 5 )(CH 2 PPh 3 )] ( 1 ) and [Ag(CF 3 CO 2 )] (1:3). The crystal structures of complexes 1 and 2 were determined by X‐ray diffraction, and the latter shows a polymeric 2D arrangement built by Au ⋅⋅⋅ Ag, Ag ⋅⋅⋅ Ag, and Ag ⋅⋅⋅ O contacts. The metallophilic interactions observed in 2 in the solid state seem to be preserved in concentrated THF solutions, as suggested by EXAFS, pulsed‐gradient spin‐echo NMR, and photophysical studies, which showed that the structural motif [AuAg 3 (C 6 F 5 )(CF 3 CO 2 ) 3 (CH 2 PPh 3 )] is maintained under such conditions. Time‐dependent DFT calculations agree with the experimental photophysical energies and suggest a metal‐to‐ligand charge‐transfer phosphorescence process. Ab initio calculations give an estimated interaction energy of around 60 kJ mol −1 for each Au ⋅⋅⋅ Ag interaction.