C–H activation by a terminal imidoiron(III) complex to form a cyclopentadienyliron(II) product
摘要:
Imido complexes of the late transition metals have the ability to activate C-H bonds through the abstraction of hydrogen atoms from hydrocarbons. This paper describes the apparent hydrogen atom transfer from cyclopentadiene (CpH) to the isolable imidoiron(III) complex L(Me)FeNAd (L(Me) = 2,4-bis(2,6-diisopropylphenylimido)pent-3-yl; Ad = 1-adamantyl) in the presence of 4-tert-butylpyridine ((t)Bupy). The isolated product is not the amidoiron(II) complex, but instead it is L(Me)Fe(Cp)((t)Bupy), the result of amido protonation by additional CpH. The crystal structures of both L(Me)FeCp and L(Me)Fe(Cp)((t)Bupy) are presented, and in the latter compound the Fe-C bonds are longer than in any previously characterized cyclopentadienyliron complex. (C) 2010 Elsevier B.V. All rights reserved.
Chemistry of Nitrosyliron Complexes Supported by a β-Diketiminate Ligand
摘要:
Several nitrosyl complexes of Fe and Co have been prepared using the sterically hindered Ar-nacnac ligand (Ar-nacnac = anion of [(2,6-diisopropylphenyl)NC(Me)](2)CH). The dinitrosyliron complexes [Fe(NO)(2)(Ar-nacnac)] (1) and (Bu4N)[Fe(NO)(2)(Ar-nacnac)] (2) react with [Fe-III(TPP)Cl] (TPP = tetraphenylporphine dianion) to generate [Fe-II(NO)(TPP)] and the corresponding mononitrosyliron complexes. The factors governing NO transfer with dinitrosyliron complexes (DNICs) 1 and 2 are evaluated, together with the chemistry of the related mononitrosyliron complex, [Fe(NO)Br(Ar-nacnac)] (4). The synthesis and properties of the related cobalt dinitrosyl [Co(NO)(2)-(Ar-nacnac)] (3) is also discussed for comparison to DNICs 1 and 2. The solid-state structures of several of these compounds as determined by X-ray crystallography are reported.