Mono- and Bis(iminoxolene)iridium Complexes: Synthesis and Covalency in π Bonding
Mono- and Bis(iminoxolene)iridium Complexes: Synthesis and Covalency in π Bonding
复制标题
单和双(亚胺氧杂环戊烯)铱配合物：α键的合成和共价键
DOI：
10.1021/acs.inorgchem.1c04005
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发表时间：
2022
影响因子：
4.6
通讯作者：
Brown, Seth N.
中科院分区：
文献类型：
--
作者：
Do, Thomas H.;Brown, Seth N.
N-（2，6-二异丙基苯基）-4，6-二叔丁基邻亚氨基苯醌（Diso）与氯化环辛二烯铱二聚体反应生成单亚氨基恶茂配合物（Diso）Ir（cod）Cl。2当量的亚氨基醌与氯双（环辛烯）铱二聚体反应得到双亚氨基氧杂环戊烯（Diso）2 IrCl。这种五配位配合物采用顶端氯配体的扭曲四方锥结构，并进行卤化物交换以形成空气稳定的碘化物配合物。（Diso）2 IrCl可以被一个电子还原，形成中性的正方形平面（Diso）2 Ir，而与PhICl 2氧化得到八面体trans-（Diso）2 IrCl 2。该cisisisomer可以通过空气氧化的（Diso）2 IrCl;顺/transomerization是没有观察到，即使在长时间加热。配合物的结构和光谱特征与金属和亚间恶茂配体之间存在强的共价π键相一致，结构数据表明π键合轨道中的铱特征在45%至60%之间，这取决于辅助配体。（Diso）2 Ir和（Diso）2 IrCl与它们的钴同系物的光谱相似性表明，第一行金属配合物同样具有明显的共价金属-亚胺氧杂环戊烯π键。
N-(2,6-Diisopropylphenyl)-4,6-di-tert-butyl-o-iminobenzoquinone (Diso) reacts with the (cyclooctadiene)iridium chloride dimer to form a monoiminoxolene complex, (Diso)Ir(cod)Cl. Reaction of 2 equiv of the iminoquinone with chlorobis(cyclooctene)iridium dimer affords the bis-iminoxolene (Diso)2IrCl. This five-coordinate complex adopts a distorted square pyramidal structure with an apical chloride ligand and undergoes halide exchange to form an air-stable iodide complex. (Diso)2IrCl can be reduced by one electron to form neutral, square planar (Diso)2Ir, while oxidation with PhICl2gives octahedraltrans-(Diso)2IrCl2. Thecisisomer can be prepared by air oxidation of (Diso)2IrCl;cis/transisomerization is not observed even on prolonged heating. Structural and spectroscopic features of the complexes are consistent with the presence of strong, covalent π bonding between the metal and the iminoxolene ligands, with structural data suggesting between 45 and 60% iridium character in the π bonding orbitals, depending on the ancillary ligands. The spectroscopic similarity of (Diso)2Ir and (Diso)2IrCl to their cobalt congeners suggests that the first-row metal complexes likewise have appreciably covalent metal-iminoxolene π bonds.