The synthesis and interactions of the cis-diaqua-chloro-tris(dimethyl sulfoxide)ruthenium(II) complex with selected sulfur-containing ligands such as 2-thiouracil, glutathione and L-cysteine have been studied by UV-Vis spectrophotometry in aqueous medium at pH 4.5. From experimental data it is clear that all three reactions proceed via two steps: the first one being a rate-limiting ligand-dependent replacement of one water molecule, followed by a ligand-independent ring closure step with the expulsion of the second water molecule. The substituted products have been characterised by Job's method, FTIR spectroscopy and electrospray ionisation mass spectrometry. Activation parameters (ΔH≠ and ΔS≠) and thermodynamic parameters (ΔH0 and ΔS0, from the temperature dependence of the outer-sphere association equilibrium constant) are presented. Consistent with the experimental findings, an associative interchange mechanism is proposed.

中文翻译：

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一些含硫​​生物活性配体在水介质中对顺式二氯三（二甲基亚砜）钌（II）配合物进行配体取代的机理方面

通过紫外-可见分光光度法在水性介质中研究了顺式-二甲基亚砜-氯-三（二甲基亚砜）钌（II）配合物与选定的含硫配体（如 2-硫尿嘧啶、谷胱甘肽和 L-半胱氨酸）的合成和相互作用在 pH 值 4.5。从实验数据可以清楚地看出，所有三个反应都通过两个步骤进行：第一个步骤是一个水分子的限速配体依赖性置换，然后是一个不依赖配体的闭环步骤，排出第二个水分子。取代的产物已通过 Job 方法、FTIR 光谱和电喷雾电离质谱进行表征。提供了活化参数（ΔH≠ 和 ΔS≠）和热力学参数（ΔH0 和 ΔS0，来自外球结合平衡常数的温度依赖性）。