20574-26-9Relevant academic research and scientific papers
Acid-catalyzed oxidation of iodide ions by superoxo complexes of rhodium and chromium
Bakac, Andreja,Shi, Chunkai,Pestovsky, Oleg
, p. 5416 - 5421 (2008/10/09)
Superoxometal complexes L(H2O)MOO2+ (L = (H 2O)4, (NH3)4, or N 4-macrocycle; M = CrIII, RhIII) react with iodide ions according to the stoichiometry L(H2O)MOO2+ + 3l- + 3H+ → L(H2O)MOH2+ + 1.5l2 + H2O. The rate law is -d[L(H2O)MOO 2+]/dt = k[L(H2O)MOO2+][l-][H +], where k = 93.7 M-2 s-1 for Cr aqOO2+, 4O2 for ([14]aneN4)(H 2O)CrOO2+, and 888 for (NH3)4(H 2O)RhOO2+ in acidic aqueous solutions at 25 °C and 0.50 M ionic strength. The CraqOO2+/l- reaction exhibits an inverse solvent kinetic isotope effect, kH2O/k D2O = 0.5. In the proposed mechanism, the protonation of the superoxo complex precedes the reaction with iodide. The related CraqOOH 2+/l- reaction has kH2O/kD2O = 0.6. The oxidation of (NH3)5Rupy2+ by Cr aqOO2+ exhibits an [H+]-dependent pathway, rate = (7.0 × 104 + 1.78 × 105[H +])[Ru(NH3)5py2+][Cr aqOO2+]. Diiodine radical anions, l2 .-, reduce CraqOO2+ with a rate constant k = 1.7 × 109 M-1 s-1.
