名称:
Three-coordinate bis(phosphinimino)methanide derivatives of ‘open shell’ [M(II)] (M=Mn, Fe, Co) transition metals
摘要:
An alternative two-step synthesis of the previously reported bis(diphenylphosphinimino)methane [CH2(Ph2P = NC6H3'Pr-2-2,6)(2)] involving bromine oxidation of dppm and metathesis with 2,6-diisopropylaniline is described. [CH2(Ph2P=NC6H3' Pr-2-2,6)(2)] is readily deprotonated by the transition metal silylamides [M{N(SiMe3)(2)}(2)] (M = Mn, Fe and Co) to provide a series of exclusively three-coordinate derivatives [{CH(Ph2PNC6H3'Pr-2-2,6)(2)M {N(SiMe3)(2)}] which have been characterised by elemental analysis, magnetic measurements and, in the case of the Fe derivative, X-ray structural analysis. Reactivity studies have shown that even such sterically demanding bis(phosphinimino)methanide ligands are prone to protonolysis and reductive [P(V) to P(III)] degradation which limits their utility as stable platforms for further M(II) derivitisation. (C) 2004 Elsevier B.V. All rights reserved.