The kinetics of base hydrolysis of chloropentakis(alkylamine)rhodium(III) ions
Abstract
The kinetics of the base hydrolysis of the complex ions [Rh(NH2R)5Cl]2+(R = Me, Et, or Prn) have been studied and values of the rate constants and activation parameters determined. For all the complexes the observed first-order rate constants were found to be proportional to the hydroxide ion concentration and to increase as the size of the amine, RNH2, increased. The increase in the rate constant was found to arise from a small but steady decrease in the activation enthalpy for the complexes and this is thought to be consistent with a SN1 (c.b.) mechanism (c.b. = conjugate base) where steric effects alone are the most important factor in controlling the difference in the rates of these reactions.