Dergiler / Turkish Journal of Chemistry / 2002 / Cilt: 26 - Sayı: 5
Base Hydrolysis Kinetics of Cobalt(III) Spiro-Octaamine Dimer
- Sayfa
- 771–776
- DOI
- —
Özet
The preparation and characterisation of a cobalt (III) complex of octaaza ligand, 5, 5'-bis(4-amino-2-azabutyl)-1,9-diamino-3,7-diazanonane (octaam) is described. The base hydrolysis kinetics of bis cobalt(III) of octaam has been studied spectrophotometrically by the stopped-flow technique. A consequent reaction is observed in the base hydrolysis of the spiro-octaamine with the fast reaction having kOH = 3.55 M-1s-1 and the slower reaction kOH = 0.72 M-1s-1} at 298 K with D H\# = 89 kJ/mol for the fast stage and D H\# = 102 kJ/mol for the slow stage (I = 0.4 M NaClO4). The fast reaction is assigned to the hydrolysis of the trans diaqua and the slower to further hydrolysis of the remaining Cl ions. The reaction appears to proceed predominantly by a DCB (dissociative conjugate base) mechanism.
Abstract
The preparation and characterisation of a cobalt (III) complex of octaaza ligand, 5, 5'-bis(4-amino-2-azabutyl)-1,9-diamino-3,7-diazanonane (octaam) is described. The base hydrolysis kinetics of bis cobalt(III) of octaam has been studied spectrophotometrically by the stopped-flow technique. A consequent reaction is observed in the base hydrolysis of the spiro-octaamine with the fast reaction having kOH = 3.55 M-1s-1 and the slower reaction kOH = 0.72 M-1s-1} at 298 K with D H\# = 89 kJ/mol for the fast stage and D H\# = 102 kJ/mol for the slow stage (I = 0.4 M NaClO4). The fast reaction is assigned to the hydrolysis of the trans diaqua and the slower to further hydrolysis of the remaining Cl ions. The reaction appears to proceed predominantly by a DCB (dissociative conjugate base) mechanism.