Altering the Localization of an Unpaired Spin in a Formal Ni(V) Species.
Altering the Localization of an Unpaired Spin in a Formal Ni(V) Species.
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改变形式 Ni(V) 物质中不成对自旋的定位。
DOI：
10.1002/chem.202302824
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发表时间：
2024
期刊：
影响因子：
--
通讯作者：
Draksharapu,Apparao
中科院分区：
文献类型：
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作者：
Awasthi,Ayushi;Mallojjala,SharathChandra;Kumar,Rakesh;Eerlapally,Raju;Hirschi,JenniferS;Draksharapu,Apparao
配体和金属中心参与氧化还原事件已被认为是获得后期 3d 金属（例如 Ni 和 Cu）正式高价配合物的方法之一。这种方法已成功用于稳定 Ni(III) 双苯氧基双自由基物质，其中配体和 Ni 局域合成自旋之间存在平衡。然而，目前的工作通过传达倾向于影响在 233 K 下 CH3CN 中报告的平衡的方法，拓宽了先前报道的三种氧化当量物种的范围。各种光谱表征表明，使用外源 N 供体配体（如 1-甲基咪唑和吡啶）有利于通过轴向结合形成以 Ni 为中心的局部自旋。相反，由于其空间位阻，喹啉有利于排他性配体局部自由基物种。 DFT 研究揭示了新型中间体复杂的电子结构。此外，还检查了具有 Ni 中心自旋的三种氧化当量物质的氢原子夺取能力，强调了它们在类似反应中的关键作用。
The participation of both ligand and the metal center in the redox events has been recognized as one of the ways to attain the formal high valent complexes for the late 3d metals, such as Ni and Cu. Such an approach has been employed successfully to stabilize a Ni(III) bisphenoxyl diradical species in which there exist an equilibrium between the ligand and the Ni localized resultant spin. The present work, however, broadens the scope of the previously reported three oxidized equivalent species by conveying the approaches that tend to affect the reported equilibrium in CH3CN at 233 K. Various spectroscopic characterization revealed that employing exogenous N‐donor ligands like 1‐methyl imidazole and pyridine favors the formation of the Ni centered localized spin though axial binding. In contrast, due to its steric hinderance, quinoline favors an exclusive ligand localized radical species. DFT studies shed light on the novel intermediates′ complex electronic structure. Further, the three oxidized equivalent species with the Ni centered spin was examined for its hydrogen atom abstraction ability stressing their key role in alike reactions.