Isotopic exchange and far-infrared studies of haloamine complexes of phodium III and iridium III.

This research has been concerned with the kinetics and mechanisms of the chlorine - 36 isotopic exchange with cis and trans [Men2Cl2] Cl, cis or trans [MtrienCl2] Cl and trans |[Rh(NH3)4Cl2] Cl where M = rhodium 111 or iridium 111, The rate constant for the exchange reactions was measured over a range of temperatures and activation parameters for the reactions calculated. The reaction was found to be first order in complex concentration but hydrogen ion concentration had no effect. At low chloride ion concentration the rate constant was found to increase as the chloride ion concentration increases until a limiting rate is reached, after which, any further increase in chloride ion concentration did not influence the rate constant. This fact was taken as indicative of ion pair formation and the accompanying association constants were calculated. Variations in rate constant for the various exchange reactions have been explained in terms of ion pair formation. Far infrared spectra of dichloro and dibromo complexes of cobalt 111, rhodium 111 and iridium 111 involving ammonia, ethylenediamine and triethylenetetramine ligands, have been measured and assignments for the metal-halogen stretching vibration and nitrogen-metal-nitrogen deformation bands, made.