Indirect excitation of Cl-(3P) in pulse-irradiated aqueous solutions. Energy transfer to TlCl/sub n//sup 1-n/ and electron transfer to Eu3+

In concentrated solutions of NaCl and greater than or equal to 0.05 M EuCl3 a prompt yield of Cl2- istributed to H2O+ and a slow yield of CL2- is attributed to electron transfer from Cl-* to Eu3+. The concentration dependence ΔG(Cl2-) vs. [Cl-] from 0.25 to 1.7 M is consistent with primary energy deposition in water and transfer from a short-lived species to Cl-. The lifetime of Cl-* is greater than 10-5 sec and it is described as Cl-(3P/sub J/). The slow yield of Cl2- decreases markedly above 2 M NaCl. With approximately 10-4 M Tl+ and concentrated KCl a luminescence under pulsed electron irradiation is the same as that under uv excitation of TlCl/sub n//sup 1-n/. The intensity increases with chloride ion concentration to approximately 2 M, then decreases markedly. The dependence is very similar for concentrated HCl and combination of CL2- with e-/sub aq/ cannot be responsible for excitation. The primary excited species appears to be produced by fast recombination of the dry charge pair, H2O+ and e-. Electron transfer from Cl- to H2O+ at high concentrations of Cl- suppresses the yield of primary excited species, presumably triplet, and possibly H2O or H3O+