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The radiation-chemical processes in aqueous solutions of dichromates, isopolymolybdates and isopolytungstates have been studied. The radiation reduction of Cr(VI) to Cr(III), Mo(VI) to Mo(V) and W(VI) to W(V) takes place. Molybdenum and tungsten blues are the products of the last two processes in acid solutions. The yields of reduction decrease significantly with the increase of pH. The mechanisms of the processes have been discussed. The photochemical reduction of Mo(VI) and W(VI) for the production of corresponding 5-valent states have been used to the study of their electron scavenging efficiencies. It has been shown that these efficiencies decrease in the order: Mo(V) > W(V) > Cr(VI) > Mo(VI) > W(VI).

Radiation reduction of binuclear [Rh2(OAc)2(phen)2(H20)2](OAc)2, [Rh2(OAc)(tpy)2C12]C1.2H20 and [Rh2C12(HCOO)2(bpy)2].4H20 complexes in aqueous-methanol solution have been studied. The reduction yields as equal to ca. 6 equiv/100 eV and the rate constants of reactions: complex+esolv as equal to 2.9.1010, 3.2.10 l~ and 3.7.10 l~ M 1.s 1, respectively, have been determined. On the basis of electronic spectra it has been shown that Rh(II) compounds were reduced giving several Rh(I) complexes being in equilibrium. The mechanism of the processes has been discussed.