The kinetics of base hydrolysis of trans-dichlorotetrakis(alkylamine)-rhodium(III) ions
Abstract
The observed pseudo-first-order rate constants for the base hydrolysis of the series of complexes trans-[Rh(NH2R)4Cl2]+(R = H, Me, Et, or Prn) have been found to depend on hydroxide ion according to Kobs.=k1+k2[OH–]. The k1 term is believed to be the aquation pathway which is operative in the bromide interchanges of these complexes, whereas the k2 term corresponds to the SN1 (c.b.)(conjugate base) mechanism. Values of the activation parameters for the base hydrolysis have also been determined and are discussed in relation to the results for similar rhodium(III), cobalt(III), and chromium(III) complexes. It is concluded that in complexes of this type rhodium(III) is less able to participate in π bonding than are cobalt(III) and chromium(III).