Emission Characteristics of Silver Atoms in γ−Irradiated Organic Solid Solutions at 77 K

Ag0 atoms were produced via the electron capture of Ag+ ions in γ-irradiated solid solutions of ethanol and MTHF at 77 K. The 2-dimensional time-resolved fluorescence spectra together with the steady-state fluorescence spectra and excitation spectra were measured by photoexcitation of Ag0 produced in the γ-irradiated solid solutions. The steady-state measurements have revealed the existence of two main emission bands at nearly 500 and 580 nm. The intensity of the 500 nm band increased and that of the 580 nm band concomitantly decreased with increasing concentration of Ag+ in both solutions. The time-resolved observation has shown that the 500 nm band consists of three components of different lifetimes (τ). The main component with τ ∼ 1 μs is attributed to the exciplex (Ag0·Ag+)*, the one with τ ∼ 2 μs, to the similar exciplex which is weakly coupled to solvent molecules, and the third one with τ ∼ 3 ns, to Ag0* trapped in a large cavity where Ag0 scarcely interacts with solvent molecules. The 580 nm band ...