Chelating or bridging? Halide-controlled binding mode of diamido donor ligands in iron(III) complexes.
In a series of iron(III) halide complexes of the form {FeX[MesN(SiMe(2))]2O}2 (Mes = mesityl; X = Cl, Br, I), the ancillary diamidosilylether ligand can either chelate to one metal or instead bridge two metal centers, as a function of the halide coligand. The complexes are prepared from diamidosilyletheriron(II) precursors, which are oxidized with iodine, benzyl bromide, or PhICl2 to yield the appropriate iron(III) halide. The bromide analogue can also be synthesized by reacting the iron(II) precursor with a bromonium transfer agent (stabilized by adamantylideneadamantane). The latter reaction may proceed via an iron(IV) intermediate, which can oxidize the normally noncoordinating, inert [B(ArF)4]- counteranion [ArF = 3,5-(CF3)2Ph].
Das
Anjan Kumar
AK
Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
Moatazedi
Zohreh
Z
Mund
Garry
G
Bennet
Andrew J
AJ
Batchelor
Raymond J
RJ
Leznoff
Daniel B
DB