Nucleophilic substitution at silicon and germanium: hydrolysis of organo-acetates

We have used a titrimetric to study the rates of hydrolysis of a series of acetates R 3 MOAc (M = S or Ge; R = Ph, iPr, nPr, c-hex) in dioxane. The effects of the concentration of water, temperature and catalysis by potassium acetate have been studied and are discussed in terms of the proposed mechanism for the hydrolysis, in which bond-breaking processes appear to be important. High orders in the water concentration are observed and the germanium acetates are much more reactive than the silicon acetates.