Oxidation of a series of tris(polypyridyl)chromium(II) ions by several cobalt(III) complexes
The kinetics of the outer-sphere oxidation of Cr(NN)/sub 3//sup 2+/ 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)/sub 3//sup 3+/ at 23 /plus minus/ 2/degree/C increase from 2.2 (/plus minus/0.3) /times/ 10/sup 3/ M/sup /minus/1/ s/sup /minus/1/ for Cr(bpy)/sub 3//sup 2+/ to 1.1 (/plus minus/0.2) /times/ 10/sup 5/ M/sup /minus/1/ s/sup /minus/1/ for Cr(4,7-Me/sub 2/-phen)/sub 3//sup 2+/ and agree very well with the values calculated by the Marcus cross relation. For Co(bpy)/sub 3//sup 3+/ and Co(phen)/sub 3//sup 3+/, 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. 22 references, 4 figures, 1 table.
- Research Organization:
- Iowa State Univ., Ames (USA)
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 5775928
- Journal Information:
- Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 27:18; ISSN INOCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
400202 -- Isotope Effects
Isotope Exchange
& Isotope Separation
AROMATICS
AZAARENES
AZINES
BIPYRIDINES
CHEMICAL REACTIONS
CHROMIUM COMPLEXES
COBALT COMPLEXES
COMPLEXES
DATA
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
KINETICS
LASER RADIATION
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENANTHROLINES
PYRIDINES
RADIATIONS
REACTION KINETICS
REDOX REACTIONS
TRANSITION ELEMENT COMPLEXES