Unusual iron(III) ate complexes stabilized by Li-π interactions

Garry Mund, Dragoslav Vidovic, Raymond J. Batchelor, James F. Britten, Rajendra D. Sharma, Colin H.W. Jones, Daniel B. Leznoff

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24 Citations (Scopus)

Abstract

Several iron(III) complexes incorporating diamidoether ligands are described. The reaction between {Li2[RN(SiMe2)] 2O} and FeX3 (X = Cl or Br; R = 2,4,6-Me3Ph or 2,6-iPr2Ph) form unusual ate complexes, {FeX2- Li[RN(SiMe2)]2O}2 (2, X = Cl, R = 2,4,6-Me 3Ph; 3, X = Br, R = 2,4,6-Me3Ph; 4, X = Cl, R = 2,6-iPr2Ph) which are stabilized by Li-π interactions. These dimeric iron(III)-diamido complexes exhibit magnetic behaviour characteristic of uncoupled high spin (S = 5/2) iron(III) centres. They also undergo halide metathesis resulting in reduced iron(II) species. Thus, reaction of 2 with alkyllithium reagents leads to the formation of iron(II) dimer {Fe[Me 3PhN(SiMe2)]2O}2 (6). Similarly, the previously reported iron(III)-diamido complex {FeCl[tBuN(SiMe 2)]2O}2 (1) reacts with LiPPh2 to yield the iron(II) dimer {Fe[tBuN(SiMe2)]2O}2 but reaction with LiNPh2 gives the iron(II) product {Fe 2(NPh2)2[tBuN(SiMe2)]2O} (5). Some redox chemistry is also observed as side reactions in the syntheses of 2-4, yielding THF adducts of FeX2: the one-dimensional chain [FeBr2(THF)2]n (7) and the cluster [Fe 4Cl8(THF)6]. The X-ray crystal structures of 3, 5 and 7 are described.

Original languageEnglish
Pages (from-to)4757-4763
Number of pages7
JournalChemistry - A European Journal
Volume9
Issue number19
DOIs
Publication statusPublished - 6 Oct 2003
Externally publishedYes

Keywords

  • Ate complexes
  • Diamido ligands
  • Iron
  • Magnetic properties
  • Moessbauer spectroscopy

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