Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Inorganic Chemistry, Egerlandstrasse 1, 91058, Erlangen, Germany.
Current address: Saarland University, Inorganic Chemistry: Coordination Chemistry, Campus C4.1, 66123, Saarbrücken, Germany.
Angew Chem Int Ed Engl. 2021 Jul 19;60(30):16480-16486. doi: 10.1002/anie.202103170. Epub 2021 Jun 18.
The reaction of the cobalt(I) complex (TIMMN )Co (2) (TIMMN =tris-[2-(3-mesitylimidazolin-2-ylidene)methyl]amine) with 1-adamantylazide yields the cobalt(III) imido complex (TIMMN )Co (NAd) (3) with concomitant release of dinitrogen. The N-anchor in diamagnetic 3 features an unusual, planar tertiary amine, which results from repulsive electrostatic interaction with the filled d(z )-orbital of the cobalt ion and negative hyperconjugation with the neighboring methylene groups. One-electron oxidation of 3 with FeCp provides access to the rare, high-valent cobalt(IV) imido complex (TIMMN )Co (NAd) (4). Despite a half-life of less than 1 h at room temperature, 4 could be isolated at low temperatures in analytically pure form. Single-crystal X-ray diffractometry and EPR spectroscopy corroborate the molecular structure and the d low-spin, S= , electron configuration. A computational analysis of 4 suggests high covalency within the Co =NAd bond with non-negligible spin density located at the imido moiety, which translates into substantial triplet nitrene character.
(TIMMN)Co（2）（TIMMN=三-[2-(3-均三甲苯基亚氨基)甲基]胺）与 1-金刚烷基叠氮化物反应生成钴(III)亚胺配合物(TIMMN)Co(NAd)（3），同时释放出氮气。在顺磁性 3 中，N 锚具有不寻常的平面叔胺，这是由于与钴离子充满的 d(z)-轨道的排斥静电相互作用和与相邻亚甲基的负超共轭作用所致。用FeCp对 3 进行单电子氧化可得到罕见的高价钴(IV)亚胺配合物(TIMMN)Co(NAd)（4）。尽管 4 在室温下的半衰期不到 1 h，但仍可在低温下以分析纯形式分离出来。单晶 X 射线衍射和 EPR 光谱证实了分子结构和 d 低自旋，S= ，电子构型。对 4 的计算分析表明，在 Co=NAd 键中存在高共价性，在亚胺部分存在不可忽略的自旋密度，这转化为大量三重态氮烯特征。
