Oxygenation of copper(I) complexes containing fluorine tagged tripodal tetradentate chelates: significant ligand electronic effects
Oxygenation of copper(I) complexes containing fluorine tagged tripodal tetradentate chelates: significant ligand electronic effects
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DOI：
10.1080/00958972.2022.2107429
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发表时间：
2022-07-28
影响因子：
1.9
通讯作者：
Hematian，Shabnam
中科院分区：
文献类型：
--
作者：
Li，Runzi;Khan，Firoz Shah Tuglak;Hematian，Shabnam
铜-分子氧（O2）相互作用在涉及可逆分子氧结合、活化或还原的生物和化学转化中非常重要。在这份报告中，我们描述了O2-反应与单核铜（I）配合物含有两个新的类似物的已知的含氮的四齿三足螯合物，三[（2-吡啶基）甲基]胺（TMPA）。在这两种衍生物中，一个富电子和一个缺电子，氟原子连接到配体框架，允许使用19 F-NMR光谱来探测氧化过程。配体电子性质的变化表现在铜配合物的电化学行为及其对O2的反应性。我们的NMR光谱研究，沿着变温电子吸收测量，揭示了铜（I）络合物与O2可逆反应形成相应的1：1铜-O2（即，末端-超氧代）中间体，其可以进一步与第二当量的铜（I）络合物可逆反应以形成相关的双核2：1铜-O2（即，反式-过氧）加合物。然而，根据螯合物的不同，在不同温度下的细节存在相当大的差异。所有的三个终端上superoxo和trans-peroxo物种在这里描述具有相似的光谱特征，虽然小，但显着的变化，其签名带的能量被观察到，这表明在螯合物的变化直接影响的电子性质的铜-O2核心。
Copper-dioxygen (O2) interactions are of great importance in biological and chemical transformations involving reversible dioxygen binding, activation, or reduction. In this report, we describe O2-reactions with the mononuclear copper(I) complexes containing two new analogues of the known nitrogen-containing tetradentate tripodal chelate,tris[(2-pyridyl)methyl]amine (TMPA). In both derivatives, one electron-rich and one electron-deficient, fluorine atoms are attached to the ligand framework, allowing for the use of19F-NMR spectroscopy to probe the oxygenation process. Variations of ligand electronic properties are manifested in the electrochemical behavior of copper complexes and their reactivities toward O2. Our NMR spectroscopic studies, along with variable-temperature electronic absorption measurements, revealed that the copper(I) complexes reversibly react with O2to form the corresponding 1:1 copper-O2(i.e.,end-onsuperoxo) intermediates which can further react reversibly with second equivalents of copper(I) complexes to form the related dinuclear 2:1 copper-O2(i.e.,trans-peroxo) adducts. However, considerable differences exist in detail at various temperatures, depending on the chelate. All threeend-onsuperoxo andtrans-peroxo species described here possess similar spectroscopic features, although small but significant shifts in the energy of their signature bands were observed, suggesting that the variation in the chelates directly affects the electronic properties of the copper-O2cores.