[en] The ligand isotopic exchange between tris(acetylacetonato)germanium(IV) perchlorate and acetylacetone[¹⁴C] has been studied in 1,1,2,2-tetrachloroethane (TCE), nitromethane (NM), and acetonitrile (AN), at 100 - 120⁰C. In these solvents, the rate formula was R = k[H₂O][complex]; the concentrations of the complex, free ligand, and water in solution were in the ranges from 0.01 to 0.1 mol dm^-3. The activation enthalpies and entropies for the k's are 105, 98, and 90 kJ mol^-1; and -25, -53, and -69 JK^-1 mol^-1, in TCE, NM, and AN, respectively. Influence of acid and base concentrations, and deuterium isotope effect on the rate in AN suggest that the rate controlling step of the exchange is governed by the ease of the proton transfer between the leaving and the incoming acac^- in an intermediate. (auth.)