Department of Chemistry , Indiana University , 800 East Kirkwood Avenue , Bloomington , Indiana 47405 , United States.
National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States.
J Am Chem Soc. 2019 Jul 31;141(30):11970-11975. doi: 10.1021/jacs.9b04389. Epub 2019 Jul 19.
Structural and spectroscopic characterization of the dimeric iron hydride complex [PhB(BuIm)FeH] reveals an unusual structure in which a tetrahedral iron(II) site ( = 2) is connected to a square planar iron(II) site ( = 1) by two bridging hydride ligands. Magnetic susceptibility reveals strong ferromagnetic coupling between iron centers, with a coupling constant of = +110(12) cm, to give an = 3 ground state. High-frequency and -field electron paramagnetic resonance (HFEPR) spectroscopy confirms this model. A qualitative molecular orbital analysis of the electronic structure, as supported by electronic structure calculations, reveals that the observed spin configuration results from the orthogonal alignment of two geometrically distinct four-coordinate iron fragments held together by highly covalent hydride ligands.
二聚铁氢化物配合物[PhB(BuIm)FeH]的结构和光谱表征揭示了一种不寻常的结构，其中一个四面体形铁(II)位（ = 2）通过两个桥联氢化物配体与一个平面正方形铁(II)位（ = 1）相连。磁化率表明铁中心之间存在强烈的铁磁性耦合，耦合常数为 = +110(12) cm，给出一个 = 3 的基态。高频和强磁场电子顺磁共振（HFEPR）光谱证实了这一模型。电子结构的定性分子轨道分析，得到电子结构计算的支持，表明观察到的自旋构型是由两个几何上不同的四配位铁片段通过高度共价的氢化物配体正交排列而产生的，这些片段由高度共价的氢化物配体固定在一起。
