| The use of FeCl2(THF)1.5 lead to the synthesis of [PhTttBu]FeCl that provided entry into new [PhTt tBu]FeX chemistry. [PhTttBu]FeCl crystallizes as a five-coordinate chloride bridged dimer that is a high-spin ferrous complex with an S = 2 ground state. The metathetical reaction of [PhTttBu]FeCl with the desired dialkylmagnesium reagent, R 2Mg (R = Me, Et, Ph, Bn), in 1,4-dioxane/THF leads to the formation of high-spin, S = 2, electronically and coordinatively unsaturated four-coordinate organoiron(II) complexes of the type, [PhTttBu]Fe(R) (R = Me, Et, Ph, Bn). Reaction of [PhTttBu]Fe(R) (R = Me, Et, Ph) with CO yields the low-spin, S = 0, six-coordinate complexes [PhTttBu]Fe(CO)2(R) (R = Me, Et, Ph). Carbonylation of [PhTttBu]Fe(Bn) yields [PhTttBu]Fe(CO) 2(Bn) and the reduced monovalent species [PhTttBu]Fe(CO) 2.;The reduction of [PhTttBu]FeCl in the presence of a phosphine ligand, PMe3 or PEt3, yields the high-spin, S = 3/2, monovalent iron complexes, [PhTttBu]Fe(PMe 3) or [PhTttBu]Fe(PEt3) in moderate yields.;[PhTttBu]Fe(PMe3) reacts with CO producing the low-spin, S = 1/2, monovalent product [PhTttBu ]Fe(CO)2. X-ray crystallographic analysis confirms a five-coordinate, square pyramidal coordination geometry. [PhTttBu]Fe(PMe 3) reacts with diphenylacetylene producing the high-spin, S = 3/2 product [PhTttBu]Fe(PhC≡CPh). X-ray crystallography confirms a five-coordinate, square pyramidal coordination geometry with PhC≡CPh bound to the iron center in a symmetric, side-on eta 2 binding mode.;[PhTttBu]Fe(PMe3) reacts with adamantyl azide producing the high-spin, S = 3/2 product, [kappa 2-PhTttBu]Fe(N4Ad2). The dialkyltetraazadiene ligand exhibits nearly identical N--N bonds suggesting a delocalized ligand radical dialkyltetraazadiene resonance form.;Efforts to model a catalytically inhibited form of COdH were performed by designing a simple Ni:Fe binuclear complex that provides the essential metal coordination spheres of the C-cluster active site. The scope of these studies was expanded to include a series of cyanide-bridged binuclear complexes, ('S3')Ni--CN--M[TptBu] (M = Fe, Co, Ni, Zn). A similar coupling scheme was used to synthesize the copper(I) analogue, Et4N{('S3')Ni--CN--Cu[TptBu]}.;Two synthetic strategies were employed to investigate the formation of cyanide-bridged linkage isomers. The products of two different 13 CN labeled reactions intended to yield ('S3')Ni--CN--Zn[Tp tBu] and ('S3')Ni--NC--Zn[TptBu] were analyzed. Nearly identical infrared and 13C NMR spectroscopic data provide additional evidence that ('S3')Ni--CN--Zn[Tp tBu] is produced in both reactions. |
