High-valent osmium iminoxolene complexes
High-valent osmium iminoxolene complexes
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高价锇亚胺氧烯配合物
DOI：
10.1039/d0dt01735c
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发表时间：
2020
影响因子：
4
通讯作者：
Brown, Seth N.
中科院分区：
文献类型：
--
作者：
Gianino, Jacqueline;Erickson, Alexander N.;Markovitz, Sean J.;Brown, Seth N.
含4-取代苯基的2-（芳基氨基）-4,6-二叔丁基苯酚（RapH2）在丙酮中与氧合物（乙二醇）锇（VI）反应生成方锥体的双（氨基苯氧）氧合物（VI）。在这些反应中可以观察到一种单氨基苯甲酸配合物作为中间体。在二氯甲烷中反应生成二氯二甲酸（Hap） 2o （OCH2CH2O）。在三甲基氯硅烷的作用下，乙醇酸盐和氧配合物都转化为相应的顺式二氯配合物。新型双（氨基酚）配体EganH4，含有乙二醇二氨基苯甲酸桥，形成螯合双（氨基苯甲酸）配合物（Egan）OsO，其中四齿配体的两个氮原子在方形金字塔的反位结合。配合物的结构和光谱特征可以用锇(VI)-氨基苯氧化合物的配方来描述，当共配体从氧变为二酸盐再变为二氯盐时，配体对金属的π给体量显著增加。在氧-二（氨基苯氧化合物）中，配体π轨道的对称性导致只有一个有效的π给体相互作用，分裂两个锇-氧π*轨道的能量，并使锇-氧键具有明显的各向异性。
2-(Arylamino)-4,6-di-tert-butylphenols containing 4-substituted phenyl groups (RapH2) react with oxobis(ethylene glycolato)osmium(VI) in acetone to give square pyramidal bis(amidophenoxide)oxoosmium(VI) complexes. A mono-amidophenoxide complex is observed as an intermediate in these reactions. Reactions in dichloromethane yield the diolate (Hap)2Os(OCH2CH2O). Both the glycolate and oxo complex are converted to the corresponding cis-dichloride complex on treatment with chlorotrimethylsilane. The novel bis(aminophenol) ligand EganH4, containing an ethylene glycol dianthranilate bridge, forms the chelated bis(amidophenoxide) complex (Egan)OsO, where the two nitrogen atoms of the tetradentate ligand bind in the trans positions of the square pyramid. Structural and spectroscopic features of the complexes are described well by an osmium(VI)-amidophenoxide formulation, with the amount of π donation from ligand to metal increasing markedly as the co-ligands change from oxo to diolate to dichloride. In the oxo-bis(amidophenoxides), the symmetry of the ligand π orbitals results in only one effective π donor interaction, splitting the energy of the two osmium-oxo π* orbitals and rendering the osmium-oxo bonding appreciably anisotropic.