Reduction of Ag-1(I)(NH3)(2)(+) to Ag-1(0)(NH3)(2) in solution. Redox potential and spectral study

Pulse radiolysis is used to determine the absorption spectra of the transient species formed during the decay of the hydrated electron in an aqueous solution of Ag-1(I)(NH3)(2)(+). The absorption spectrum attributed to Ag-1(0)(NH3)(2) presents three peaks at 345, 385, and 435 nm, A theoretical estimation of the redox potential of the couple Ag-1(I)(NH3)(2)(+)/Ag-1(0)(NH3)(2) yields the value -2.4 V-NHE. This value is consistent with the fact that Ag-1(I)(NH3)(2)(+) is not directly reduced by (CH3)(2)CoverdotO(-) and shows that the redox potential of the silver monomer couple is lowered by ammonia ligands.