| Popis: |
The kinetics of reaction between thiourea and [RuIII (H-EDTA)(H2O)] (1) were investigated in aqueous solution as a function of pH, temperature and metal ion concentration at 0.1 M ionic strength using the stopped flow technique. It was established that the monoanionic species of complex 1, [RuIIIEDTA)(H2O)]− (2) is the major reacting species over the pH range 1.5–8.5. The substitution reaction follows first-order kinetics in [Ru(EDTA)(H2O)]− as well as in thiourea concentrations over a wide concentration range of the two reactants. The rate constant (k1) was found to be (2.04 ± 0.17) × 10 3 M−1 s−1 at 25°C and μ = 0.1 M (KCl). From the activation parameters of the reaction it was concluded that the substitution reaction of [Ru(EDTA)H2O]− follows an associative mechanism. The reactivities of different species of the thiourea complexes formed, have also been discussed. |
