Bis-hydroxylaminato group 4 half-sandwich complexes-syntheses, structures and polymerisation activity studies

摘要

The methylene-and ethylene-bridged bis-hydroxylamines HONMe(CH2)(n)NMeOH (n = 1, 2) were reacted with [Cp*TiCl3], [Cp*ZrCl3] and [Cp*HfCl3] in the presence of MeLi to give the complexes [Cp*TiMe{(eta(2)-ONMe)(2)CH2}] (1), [Cp*TiMe{(eta(2)-ONMeCH2)(2)}] (2), [Cp*ZrMe{(eta(2)-ONMeCH2)(2)}] (3) and [Cp*HfMe{(eta(2)-ONMeCH2)(2)}] (4). The reaction of 2 with AlMe3 afforded the adduct [Cp*TiMe{eta(2)-[O(AlMe3)NMe]CH2CH2-eta(2)-(NMeO)}] (2 center dot AlMe3). The compounds were characterised by NMR spectroscopy, elemental analyses and mass spectrometry. Their crystal structures were determined by X-ray diffraction. In each case, all four donor atoms of the [2 + 2]-dentate ligands coordinate in a eta(2)-manner to the organometallic [Cp*MMe] complex fragments. The polymerisation reactions of ethylene and propylene catalysed by 2 activated with methylalumoxane (MAO) were