Fe(II) Mononuclear Complexes with a New Aminopyridyl Ligand Bearing a Pivaloylamido Arm. Preparation and Spectroscopic Characterizations of a FeIII-Hydroperoxo Complex with Oxygen and Nitro

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• 作者：Marl&egrave ; ne Martinho ; Fré ; dé ; ric Banse ; Joë ; lle Sainton ; Christian Philouze ; Ré ; gis Guillot ; Guillaume Blain ; Pierre Dorlet ; Sophie Lecomte ; Jean-Jacques Girerd
• 刊名：Inorganic Chemistry
• 出版年：2007
• 出版时间：March 5, 2007
• 年：2007
• 卷：46
• 期：5
• 页码：1709 - 1717
• 全文大小：194K
• 年卷期：v.46,no.5(March 5, 2007)
• ISSN：1520-510X

文摘

Two new mononuclear Fe^II complexes, [(L₅²aH)Fe^II](PF₆)₂ (1-(PF₆)₂) and [(L₅²a)Fe^II]BPh₄ (2-(BPh₄)) have beensynthesized with the new aminopyridyl ligand bearing a pivaloylamido arm L₅²aH (2,2-dimethyl-N-[6-({[2-(methyl-pyridin-2-ylmethyl-amino)-ethyl]-pyridin-2-ylmethyl-amino}-methyl)-pyridin-2-yl]-propionamide), or its deprotonated formL₅²a^-. The structures of the ferrous complexes have been determined by X-ray analysis. The mononuclear Fe^II isin a pseudo-octahedral environment in both complexes, the six positions around the metal center being occupiedby five nitrogen atoms and one oxygen atom from the ligand. Whatever the protonation state of the amide function,the structures are very similar, the Fe^II being 6-fold coordinated by the two amines, three pyridines, and the oxygenatom from the ligand. These two complexes exhibit an acid/base equilibrium in solution that has been studied byUV-vis spectroscopy and cyclic voltammetry in acetonitrile. The reactivity of 1-(PF₆)₂ with H₂O₂ in methanol affordsthe formation of a new low-spin Fe^III(OOH) intermediate in which the oxygen atom is retained in the coordinationsphere of the metal.