Controlled Flexible Coordination in Tripodal Iron(II) Phosphane Complexes: Effects on Reactivity

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• 作者：Anette Petuker ; Klaus Merz ; Christian Merten ; Ulf-Peter Apfel
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：February 1, 2016
• 年：2016
• 卷：55
• 期：3
• 页码：1183-1191
• 全文大小：410K
• ISSN：1520-510X

文摘

The possibility to alter properties of metal complexes without significant steric changes is a useful tool to tailor the reactivity of the complexes. Herein we present the synthesis of iron complexes with the tripodal phosphane ligands Triphos and Triphos^Si and report on their different coordination properties. Whereas reaction of Triphos^Si and FeX₂ (X = Cl, Br) exclusively afforded (Triphos^Si)FeX₂ with a κ²-coordinated ligand, the homologous C-derived Fe complexes show rapid conversion in solution to afford [(Triphos)Fe(CH₃CN)₃][Fe₂Cl₆] or [(Triphos)Fe(CH₃CN)₃][FeBr₄], respectively. The structural conversion was found to be temperature- and solvent-dependent and was accompanied by a linear change of the overall magnetization. The different ligand influence was shown to have a significant effect on the ability of (Triphos^Si)FeCl₂ and (Triphos)FeCl₂ to perform the Sonogashira cross-coupling reaction of 4-iodotoluene and phenyl acetylene as well as the hydrosilylation of acetophenone. The results presented herein show the different coordination properties of two structurally homologous tripodal ligands and demonstrate the importance of geometrically controlled ligand field splitting on the stability and reactivity of metal complexes. The C/Si exchange therefore provides a simple and straightforward tool to manipulate properties and reactivity of metal complexes.