Xu Gan, Cui Yun-Shu, Jiang Xue-Lian, Xu Cong-Qiao, Li Jun, Chen Xu-Dong
Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.
Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.
Natl Sci Rev. 2023 Dec 22;11(4):nwad327. doi: 10.1093/nsr/nwad327. eCollection 2024 Apr.
Iron-metal clusters are crucial in a variety of critical biological and material systems, including metalloenzymes, catalysts, and magnetic storage devices. However, a synthetic high-nuclear iron cluster has been absent due to the extreme difficulty in stabilizing species with direct iron-iron bonding. In this work, we have synthesized, crystallized, and characterized a (Tp*)WS(Fe@Fe) cluster (Tp* = tris(3,5-dimethyl-1-pyrazolyl)borate(1-)), which features a rare trideca-nuclear, icosahedral [Fe@Fe] cluster core with direct multicenter iron-iron bonding between the interstitial iron (Fe) and peripheral irons (Fe), as well as Fe···Fe ferromagnetic coupling. Quantum chemistry studies reveal that the stability of the cluster arises from the 18-electron shell-closing of the [Fe@Fe] core, assisted by its bonding interactions with the peripheral tridentate [(Tp*)WS] ligands which possess both S→Fe donation and spin-polarized Fe-W σ bonds. The ground-state electron spin is theoretically predicted to be S = 32/2 for the cluster. The existence of low oxidation-state (OS ∼ +1.23) iron in this compound may find interesting applications in magnetic storage, spintronics, redox chemistry, and cluster catalysis.
铁金属簇在各种关键的生物和材料体系中至关重要，包括金属酶、催化剂和磁存储设备。然而，由于稳定具有直接铁-铁键合的物种极其困难，合成的高核铁簇一直缺失。在这项工作中，我们合成、结晶并表征了一种（Tp*）WS（Fe@Fe）簇（Tp* = 三（3,5-二甲基-1-吡唑基）硼酸根（1-）），其具有罕见的十三核二十面体[Fe@Fe]簇核，在间隙铁（Fe）和外围铁（Fe）之间存在直接的多中心铁-铁键合以及Fe···Fe铁磁耦合。量子化学研究表明，该簇的稳定性源于[Fe@Fe]核的18电子闭壳层，这得益于其与外围三齿配体[（Tp*）WS]的键合相互作用，该配体兼具S→Fe给体作用和自旋极化的Fe-W σ键。理论预测该簇的基态电子自旋为S = 32/2。该化合物中低氧化态（OS ∼ +1.23）铁的存在可能在磁存储、自旋电子学、氧化还原化学和簇催化方面有有趣的应用。
