Kinetic and Mechanistic Studies on the Reaction of DL-Methionine with[(H2O)(tap)2RuORu(tap)2(H2O)]2+in Aqueous Medium at Physiological pH

[摘要] The reaction has been studied spectrophotometrically; the reaction shows two steps, both of which are dependent on ligand concentration and show a limiting nature. An associative interchange mechanism is proposed. Kinetic and activation parameters (k1∼10−3s−1andk2∼10−5s−1) and (ΔH1  ≠=13.8±1.3 kJ mol−1,ΔS1  ≠=−250±4 JK−1 mol−1,ΔH2  ≠=55.53±1.5 kJ mol−1, andΔS2  ≠=−143±5 JK−1 mol−1) have been calculated. From the temperature dependence of the outer sphere association equilibrium constant, thermodynamic parameters (ΔH1  ∘=16.6±2.3 kJ mol−1andΔS1  ∘=95±7 JK−1 mol−1;ΔH2  ∘=29.4±3.2 kJ mol−1andΔS2  ∘=128±10 JK−1 mol−1) have also been calculated.

[学科分类] 无机化学