Phenolat‐Komplexe von Eisen(II) in unterschiedlichen Spinzuständen

Abstract

Im Jahre 1996 wurde über [{(h 5 -C 5 HiPr 4 )Fe(m-Br)} 2 ] (1 a) als ersten High-Spin-Cyclopentadienylkomplex des Eisens berichtet.[

[Cp′FeI]2 as convenient entry into iron-modified pincer complexes: bimetallic η6,κ1-POCOP-pincer iron iridium compounds

“…Previous reports stated that 1-Br and the related [ 4 CpFeBr] 2 and [ 5 CpFeBr] 2 complexes do not undergo a spin-state change when dissolved in coordinating solvents. 33,34 We can confirm this observation for 1-I in ether and acetone solvents. In both cases yellow, paramagnetic mono-solvent adducts (Evans' solution moment: m eff (292 K) = 5.3(2) m B (S = 2)) are formed.…”

“…Sitzmann and co-workers reported the synthesis of [( n Cp)FeBr] 2 ( 5 Cp = C 5 (CHMe 2 ) 5 , 4 Cp = C 5 H(CHMe 2 ) 4 and Cp 0 = 1,2,4-C 5 H 2 (CMe 3 ) 3 ) without additional donor ligands. 33,34 These species can be isolated as stable compounds and react with substituted phenolates to yield monomeric and dimeric complexes depending on the steric bulk of the phenolate ligand. 34 More recently s/p-rearrangements of aryl ligands connected to the Cp 0 Fefragment have been reported, [35][36][37] whereas the related 5 CpFe(C 5 H 3 -2,6-(iPr) 2 ) complex exhibits single-molecule magnet behavior.…”

“…33,34 These species can be isolated as stable compounds and react with substituted phenolates to yield monomeric and dimeric complexes depending on the steric bulk of the phenolate ligand. 34 More recently s/p-rearrangements of aryl ligands connected to the Cp 0 Fefragment have been reported, [35][36][37] whereas the related 5 CpFe(C 5 H 3 -2,6-(iPr) 2 ) complex exhibits single-molecule magnet behavior. 38 We have recently set out to investigate the reactivity of the related [Cp 0 FeI] 2 molecule as a synthon to attractive target molecules similar to the extensive [(C 5 Me 5 )RuX] n half-sandwich chemistry.…”

Benzylidyne Bridges from Diphenylacetylene and a Methylidyne Bridge from Methylmagnesium Chloride

“…The (C 5 H 2 t Bu 3 -1,2,4) cent −Fe distance (1.97 Å) is in the typical range for iron(II) high-spin complexes, and the Fe−Br distances are slightly shorter than comparable distances in 1. 55 The sodium bromide distances are negligibly shorter than the sum of ionic radii of sodium and bromide (2.98 Å 69 ), respectively.…”

“…The suspicion of complex formation with nitrogen could be confirmed in the meantime 52,53 and will be the subject of a subsequent publication. 54 Initially we resorted, however, to diphenylacetylene as another triply bonded reaction partner in order to learn more about the reactivity of bulky alkylcyclopentadienyliron complexes such as [(C 5 H 2 t Bu 3 -1,2,4)Fe(μ-Br)] 2 (1), 55 64 Bis{tri(tert-butyl)cyclopentadienyliron(II) bromide} (1) and Its Reaction with Diphenylacetylene under Reducing Conditions. In a short communication the crystal structure of the bromo-bridged dimer 1 has been reported.…”