Ott Jonas C, Wadepohl Hubert, Gade Lutz H
Anorganisch-Chemisches Institut, Universität Heidelberg, Im Neuenheimer Feld 276, 69120 Heidelberg, Germany.
Inorg Chem. 2021 Mar 15;60(6):3927-3938. doi: 10.1021/acs.inorgchem.0c03724. Epub 2021 Feb 23.
A study of the reactivity of a T-shaped iron(I) complex supported by a carbazole-based PNP pincer ligand () has established its strongly reducing character and propensity to bind small molecules with concomitant transfer of charge and spin density. Metalloradical reactivity was observed in the reaction with the stable radical 2,2,6,6-tetramethylpiperidinyloxyl (TEMPO) yielding the corresponding Fe hydroxylaminato complex . Complex reacted rapidly and selectively with two molecules of carbon monoxide to give the corresponding low-spin dicarbonyl complex . When reacted with phenylacetylene, the alkyne complex was isolated in which the alkyne was found to bind side-on as an η-ligand, which adopts radical anion character as a result of charge transfer from the metal center. Reaction with diphenyl diazomethane generated an adduct in which the diazoalkane also appears to be partially reduced and acquires radical character. Upon exposure to carbon dioxide, oxygen atom abstraction was observed, ultimately leading to the isolation of the monocarbonyl iron(I) complex and a dinuclear carboxylato ferrous complex . Furthermore, reaction with chalcogen atom transfer reagents resulted in the formation of the corresponding dinuclear ferrous chalcogenido compounds (E = S (), Se ()), which were found to display strong antiferromagnetic coupling (, = -68 cm; : = -58 cm).
一项关于由咔唑基PNP钳形配体（）支撑的T形铁（I）配合物反应活性的研究，确定了其强还原特性以及结合小分子并伴随电荷和自旋密度转移的倾向。在与稳定自由基2,2,6,6-四甲基哌啶氧基（TEMPO）的反应中观察到金属自由基反应活性，生成了相应的铁羟胺配合物。配合物与两分子一氧化碳迅速且选择性地反应，生成相应的低自旋二羰基配合物。当与苯乙炔反应时，分离出炔烃配合物，其中炔烃以η-配体的形式侧基配位，由于金属中心的电荷转移而具有自由基阴离子特征。与二苯基重氮甲烷反应生成加合物，其中重氮烷似乎也被部分还原并具有自由基特征。暴露于二氧化碳时，观察到氧原子夺取反应，最终分离出单羰基铁（I）配合物和双核羧酸亚铁配合物。此外，与硫族原子转移试剂反应导致形成相应的双核亚铁硫族化物化合物（E = S（），Se（）），发现它们表现出强反铁磁耦合（， = -68 cm；： = -58 cm）。
