Department of Chemistry , Yale University , 225 Prospect Street , New Haven , Connecticut 06520 , United States.
Max-Planck-Insitut für Chemische Energiekonversion , Mülheim an der Ruhr , Germany.
J Am Chem Soc. 2018 Jul 11;140(27):8586-8598. doi: 10.1021/jacs.8b04828. Epub 2018 Jun 29.
Distinguishing the reactivity differences between N complexes having different binding modes is crucial for the design of effective N-functionalizing reactions. Here, we compare the reactions of a K-bridged, dinuclear FeNNFe complex with a monomeric Fe(N) complex where the bimetallic core is broken up by the addition of chelating agents. The new anionic iron(0) dinitrogen complex has enhanced electron density at the distal N atoms of coordinated N, and though the N is not as weakened in this monomeric compound, it is much more reactive toward silylation by (CH)SiI (TMSI). Double silylation of N gives a three-coordinate iron(III) hydrazido(2-) complex, which is finely balanced between coexisting S = 1/2 and S = 3/2 states that are characterized by crystallography, spectroscopy, and computations. These results give insight into the interdependence between binding modes, alkali dependence, reactivity, and magnetic properties within an iron system that functionalizes N.
区分具有不同结合模式的 N 配合物之间的反应性差异对于设计有效的 N 官能化反应至关重要。在这里，我们比较了具有桥联的双核 FeNNFe 配合物与单核 Fe(N) 配合物的反应，其中双金属核通过添加螯合剂而被打断。新的阴离子铁(0)二氮配合物在配位 N 的远端 N 原子上具有增强的电子密度，尽管在这个单核化合物中 N 没有被削弱，但它对(CH)SiI (TMSI)的硅烷化反应要活跃得多。N 的双硅烷化反应生成三配位铁(III)腙(2-)配合物，它在共存的 S = 1/2 和 S = 3/2 态之间精细平衡，这些态通过晶体学、光谱学和计算来表征。这些结果深入了解了在铁体系中，N 官能化的结合模式、碱依赖性、反应性和磁性之间的相互依存关系。
