Iron in a Trigonal Tris(alkoxide) Ligand Environment
摘要:
Mononuclear Fe(II) and Fe(III) complexes residing in a trigonal tris(ditox) (ditox = Bu-t(2)(Me)CO-) ligand environment have been synthesized and characterized. The Fe(III) ditox complex does not react with oxidants such as PhIO, whereas NMe3O substitutes a coordinated tetrahydrofuran (THF) in the apical position without undergoing oxo transfer. In contrast, the Fe(II) ditox complex reacts rapidly with PhIO or Me3NO in THF or cyclohexadiene to furnish a highly reactive intermediate, which cleaves C-H bonds to afford the Fe(III)-hydroxide complex. When generated in 1,2-difluorobenze, this intermediate can be intercepted to oxidize phosphines to phosphine oxide. The fast rates at which these reactions occur is attributed to a particularly weak ligand field imparted by the tris(alkoxide) ancillary ligand environment.
Pseudotetrahedral d<sup>0</sup>, d<sup>1</sup>, and d<sup>2</sup> Metal−Oxo Cores within a Tris(alkoxide) Platform
作者:Stanislav Groysman、Dino Villagrán、Daniel G. Nocera
DOI:10.1021/ic101968s
日期:2010.12.6
Low-coordinate first-row metal complexes of d0 [vanadium(V)], d1 [chromium(V)], and d2 [chromium(IV)] assume the unusual ligand field of a pseudotetrahedron when supported by a tripodal tBu2(Me)CO− alkoxide framework. Structural, spectroscopic, and reactivity studies, supported by density functional theory calculations, indicate that the d electrons in the chromium(V) and -(IV) oxo complexes reside in metal−oxygen