Rhodium(III) complexes containing unidentate amines
Abstract
Convenient syntheses of [Rh(NRH2)5X]2+(R = Me, Et, Prn, Bun, or Bui; X = Cl or Br), trans-[Rh(NR′H2)4Cl2]+(R′= Pri, cyclohexyl, or Ph), and trans-[Rh(pyr)4Cl2]+(pyr = pyrrolidine) are reported and [Rh(NRH2)5Cl]2+ is shown to be a convenient starting material for the synthesis of trans-[Rh(NRH2)4Cl2]+. Polarographic half-wave reduction potentials are reported together with physical and spectroscopic properties. The rate of exchange of amino-protons in trans-[Rh(NMeH2)4Cl2]+ and the rate constants and activation parameters for the substitution of chloride by bromide in [Rh(NRH2)5Cl]2+ and trans-[Rh(NRH2)4Cl2]+(R = Me, Et, or Prn) have been determined and are compared with data on related complexes of RhIII, CoIII, and CrIII.