ISSN:
1573-9171
Keywords:
organometallic compounds
;
cobalt—carbon bond
;
redox potentials
;
cobalt(IV)
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Redox potentials of a series of complexes of cobalt(II) and organocobalt(III) with tetraazamacrocyclic (N4) and N2O2-noncyclic polychelate ligands have been determined by cyclic voltammetry. Introduction of ano-phenylene fragment instead of an ethylene fragment into an equatorial ligand and/or exchange of an N4-coordination chromophore for the N2O2-analog has been shown to result in the anodic shift of redox potentials of MeCo(IV)L/ MeCo(III)L, MeCo(III)L/MeCo(II)L, and Co(II)L/Co(I)L pairs. It has been established that the solvent effect on redox potential is larger for Co(III)L/Co(II)L than for other pairs. Apparently, this is the first case when quasi-reversible stages of oxidation of MeCo(III)L to MeCo(IV)L+ and MeCo(IV)L+ to [MeCo(IV)L]2+ can be simultaneously observed. A. relatively stable complex of methylcobalt(IV) with a long lifetime at ∼20 °C has been registered by the ESR method.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00704180
