Synthesis of Iron and Cobalt Complexes of a Ferrocene-Linked Diphosphinoamide Ligand and Characterization of a Weak Iron–Cobalt Interaction

A ferrocene-based bis­(phosphinoamine) fc­(NHPiPr2)2 has been deprotonated and used in salt metathesis reactions to form dimeric complexes ([fc­(NPiPr2)2]­M)2 (M = Fe, Co). A novel coordination environment for Co­(II) is observed including a weak but significant Fe–Co interaction, which was characterized using X-ray crystallography, Mössbauer spectroscopy, and VT-magnetometry. Density functional theory (DFT) calculations including natural bond order analysis provides further support for the interaction and suggests a combination of Fe → Co and Co → Fe interactions.一种基于二茂铁的双(膦胺)配体fc(NHPiPr2)2经去质子化后，可参与复分解反应，生成二聚配合物([fc(NPiPr2)2]M)2（M = Fe、Co）。研究中观测到一种针对Co(II)的新型配位环境，其中存在弱但显著的Fe-Co相互作用，该相互作用通过X射线晶体衍射、穆斯堡尔谱学（Mössbauer spectroscopy）及变温磁测量（VT-magnetometry）得以表征。密度泛函理论（Density Functional Theory, DFT）计算结合自然键轨道分析，为该相互作用提供了进一步的理论支撑，并表明其为Fe→Co与Co→Fe相互作用的复合模式。