Reaktivität von Koordinationsverbindungen XXII [1]. Zur Kinetik der O2-Aufnahme von Kobalt(II)-Chelaten 3-zähniger Amine und Amide
✍ Scribed by P. Donatsch; K. H. Gerber; A. Zuberbühler; S. Fallab
- Publisher
- John Wiley and Sons
- Year
- 1970
- Tongue
- German
- Weight
- 447 KB
- Volume
- 53
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
The kinetics of the interaction between molecular oxygen and the Co2+-cornplexes of the three terdentate ligands 2, N-(2-picoly1)-ethylenediamine (FEN), N-(2-picoly1)-oxamide (POA) and diethylenetriamine (DIEN) have been studied spectrophotometrically and using an 0, specific Clark electrode. Starting from the respective 1 : 1and 1 : 2-complexes, the binuclear species ZCoO,(OH)CoZ and Z,CoO,CoZ, are formed with each ligand. The existence of the former product shows that a minimum of three chelating nitrogen donors is sufficient to make a Coz+-complex reactive towards 0,.
As derived from the empirical rate laws the same general reaction mechanism must be valid for all three systems. In the case of PEN-and DIEN-complexes the oxygen adducts are metastable intermediates and formed in stoichiometric quantities. With POA irreversible formation of cobaltic species is rapid, and 0,-adducts are present in steady state concentrations only, except in strongly basic solutions.