58220-56-7Relevant academic research and scientific papers
Oxidation of a series of tris(polypyridyl)chromium(II) ions by several cobalt(III) complexes
Zahir, Khurram,Espenson, James H.,Bakac
, p. 3144 - 3146 (2008/10/08)
The kinetics of the outer-sphere oxidation of Cr(NN)32+ ions (NN = 2,2′-bipyridine, 1,10-phenanthroline, and their substituted derivatives) by tris(chelating ligand) complexes of Co(III) were studied. The second-order rate constants increase with the driving force of the reaction. The rate constants for Co(en)33+ at 23 ± 2°C increase from 2.2 (±0.3) × 103 M-1 s-1 for Cr(bpy)32+ to 1.1 (±0.2) × 105 M-1 s-1 for Cr(4,7-Me2-phen)32+ and agree very well with the values calculated by the Marcus cross relation. For Co(bpy)33+ and Co(phen)33+, on the other hand, the experimental rate constants are lower than the calculated values. It is suggested that the reactions of these two species are mildly nonadiabatic, the extent of nonadiabaticity increasing with an increase in the standard free energy of the reaction.
