Controlling Reactivity of Copper(II) Acylperoxide Complexes
Controlling Reactivity of Copper(II) Acylperoxide Complexes
复制标题
控制酰基过氧化物铜(II)配合物的反应性
DOI：
10.1021/acs.inorgchem.1c00475
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发表时间：
2021
期刊：
影响因子：
4.6
通讯作者：
and Shinobu Itoh
中科院分区：
文献类型：
--
作者：
Yuma Morimoto;Makito Kawai;Aya Nakanishi;Hideki Sugimoto;and Shinobu Itoh
金属单加氧酶的氧化还原状态通过在金属中心上施加特定的配位环境以降低用于活性氧物质的产生和随后的底物氧化反应的活化能来微调。在这项研究中，铜（II）配合物支持的一系列线性四齿配体组成的刚性6-，7-，或8-元环二胺与两个吡啶甲基（-CH 2 Py）侧臂（L 6 Pym 2，L7 Pym 2，和L 8 Pym 2）被用来检查其酰基过氧化物加合物的反应性的配位环境的影响。紫外-可见光谱和电子顺磁共振光谱数据表明，随着二胺环尺寸的增大，配位场在配合物的dx 2-y2和dz 2轨道之间的分裂增大（L 6Pym 2 → L7 Pym 2 → L 8 Pym 2）.在与间氯过氧苯甲酸（m-CPBA）的反应中，L 6Pym 2配合物生成稳定的间氯过氧苯甲酸（m-CPBA）加合物，而L7 Pym 2和L 8 Pym 2配合物则立即转化为相应的间氯过氧苯甲酸（m-CBA）加合物，表明酰基过氧铜配合物的反应性在很大程度上取决于支持配体诱导的配位环境.密度泛函理论（DFT）计算表明，配体场分裂能量的增加与二胺部分的环尺寸的增加，在起始铜（II）配合物的情况下，这增强了它们-CPBA加合物的反应性。通过密度泛函理论计算，对它们-CPBA加合物反应活性不同的原因进行了分析。
The redox state of the metallomonooxygenases is finely tuned by imposing specific coordination environments on the metal center to reduce the activation energy for the generation of active-oxygen species and subsequent substrate oxygenation reactions. In this study, copper(II) complexes supported by a series of linear tetradentate ligands consisting of a rigid 6-, 7-, or 8-membered cyclic diamine with two pyridylmethyl (−CH2Py) side arms (L6Pym2,L7Pym2, andL8Pym2) are employed to examine the effects of the coordination environment on the reactivity of their acylperoxide adduct complexes. The UV–vis and electron paramagnetic resonance spectroscopic data indicate that the ligand-field splitting between the dx2–y2and dz2orbitals of the starting copper(II) complexes increase with an increase of the ring size of the diamine moiety (L6Pym2→L7Pym2→L8Pym2). In the reaction of these copper(II) complexes withm-chloroperbenzoic acid (m-CPBA), theL6Pym2complex gives a stablem-CPBA adduct complex, whereas theL7Pym2andL8Pym2complexes are immediately converted to the correspondingm-chlorobenzoic acid (m-CBA) adducts, indicating that the reactivity of the copper(II) acylperoxide complexes largely depends on the coordination environment induced by the supporting ligands. Density functional theory (DFT) calculations on them-CPBA adduct complexes show that the ligand-field-splitting energy increases with an increase of the ring size of the diamine moiety, as in the case of the starting copper(II) complexes, which enhances the reactivity of them-CPBA adduct complexes. The reasons for such different reactivities of them-CPBA adduct complexes are evaluated by using DFT calculations.