Abstract

A series of amido-titanium and -zirconium complexes containing a tripodal amide with a trisilylsilane ligand framework has been prepared. The primary isolable products in the reaction of SiMe (SiMe 2NHR) 3 (R = 4-MeC 6H 4, 2-FC 6H 4 or 4-MeOC 6H 4) with LiBu n and ZrCl 4 in diethyl ether are the Li(OEt 2) 2Cl adducts of which the five-co-ordinate complex {(4-MeOC 6H 4NSiMe 2) 3MeSi}Zr(μ-Cl) 2Li(OEt 2) 2 and the six-co-ordinate {(2-FC 6H 4NSiMe 2) 3MeSi}Zr(μ-Cl) 2Li(OEt 2) 2 have been characterised by X-ray crystallography. In the latter one of the fluorine atoms of the peripheral 2-FC 6H 4 groups is weakly co-ordinated to the metal. Stirring of the (Et 2O) 2LiCl adducts in toluene generates the four-co-ordinate complexes Zr{SiMe(SiMe 2NR) 3}Cl. Upon reaction of M{SiMeSiMe 2N(C 6H 4F-2)] 3}Cl] (M = Ti or Zr) with AgO 3SCF 3 the corresponding triflates were obtained which are sufficiently stable to be isolated. The halide ligand may be readily substituted to give the corresponding methyl, ethynyl and cyclopentadienyl complexes.