Phenolate Complexes of Iron(II)in Different Spin States

摘要

In 1996,[(~4CpFe(mu-Br))_2](la,~ 4Cp = eta~5-C_5H(CHMe_2)_4)was reported as the first high-spin cyclopentadienyliron complex,but could not be prepared as single crystals.With the tri(tert-butyl)cyclopentadienyl derIVatIVe [Cp"'Fe(mu-Br)]_2(1b,Cp"' = eta~5-l,3,4-tBu_3C_5H_2)structural information can now be obtained.Because the alkylcyclopentadienyl ligands employed are bulky enough to hinder unwanted ligand redistribution reactions that result in ferrocene formation,la and 1b offer interesting synthetic possibilities.Reactions of complexes 1 with substituted phenolates reveal a delicate balance between different coordination modes(Scheme 1).