Inspired by the reactivity of (per)chlorate reducing molybdoenzymes and encouraged by the lack of molybdenum-containing functional models thereof, two molybdenum(VI) complexes of the type [MoO₂L₂] (L = pyrimidine-2-thiolate or 6-methylpyridine-2-thiolate) were found to be active homogeneous catalysts for the reduction of ClO₄^– to ClO₃^– in CH₂Cl₂ using PPh₃ as sacrificial oxygen acceptor. The subsequent stepwise reduction of ClO₃^– to Cl^– is facilitated by our catalysts, but it can also proceed with only PPh₃ without the aid of a catalyst. We followed the decrease in perchlorate concentration in the catalytic solutions not only indirectly by oxidation of PPh₃ to OPPh₃ via ¹H NMR spectroscopy but also directly by determining the perchlorate concentration at certain time points over 24 h with high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS/MS). These experiments revealed the pyrimidine-2-thiolate system to be more efficient. The reduction of ClO₄^– to ClO₃^– with [MoOL₂], which is generated after the reaction of [MoO₂L₂] with PPh₃, was computed to be highly exergonic with low kinetic barriers for both catalysts. Thus, the rate-determining step of the overall catalytic reaction is the initial oxygen atom transfer from [MoO₂L₂] to PPh₃.

中文翻译：

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使用钼配合物的受自然启发的均相催化高氯酸盐还原

受（高）氯酸盐还原钼酶反应性的启发，并受到其含钼功能模型的缺乏的启发，两种 [MoO ₂ L ₂ ]型钼 (VI) 配合物（L = 嘧啶-2-硫醇盐或 6-甲基吡啶-2-硫醇盐）被发现是用于CLO的还原活性的均相催化剂₄ ^-至C10 ₃ ^-在CH ₂氯₂使用PPH ₃作为牺牲氧受体。CLO随后逐步降低₃ ^-到氯^-是我们的催化剂促进，但它也可以继续只用PPH ₃没有催化剂的帮助。我们不仅通过¹ H NMR 光谱将 PPh ₃氧化为 OPPh ₃间接跟踪催化溶液中高氯酸盐浓度的降低，而且还通过高效液相色谱-感应法直接测定 24 小时内某些时间点的高氯酸盐浓度耦合等离子体质谱法 (HPLC-ICPMS/MS)。这些实验表明嘧啶-2-硫醇盐系统更有效。[MoO ₂ L ₂ ] 与 PPh ₃反应后生成的[MoOL ₂ ]将 ClO ₄ ^–还原为 ClO ₃ ^–, 被计算为两种催化剂的高能和低动力学障碍。因此，整个催化反应的速率决定步骤是初始氧原子从 [MoO ₂ L ₂ ] 到 PPh _{3 的}转移。