Argentophilic Interactions in Solution: An EXAFS Study of Silver(I) Nitrene Transfer Catalysts.

Silver(I) catalysts have been developed for nitrene transfer reactions such as aziridination and C-H insertion. For some catalysts, structures determined by X-ray crystallography reveal dimers with silver-silver interactions, leading to mechanistic speculation about the potential role of dinuclear silver complexes in catalysis. However, it is often unclear if the silver-silver interactions persist in solution. Here we use EXAFS to directly interrogate the solution-phase structures of several silver(I) nitrene transfer catalysts. Retention or loss of the silver-silver interaction in solution can be clearly observed.