MONO(AMIDO-DIPHOSPHINE) COMPLEXES OF YTTRIUM - SYNTHESIS AND X-RAY CRYSTAL-STRUCTURE OF (Y(ETA-3-C3H5)[N(SIME2CH2PME2)2])2(MU-CL)2

The reaction of allylmagnesium chloride with the bis(amido-phosphine) complex YCl[N(SiMe2CH2PMe2)2]2 (1) results in displacement of one of the tridentate ligands rather than simple metathesis of the chloride to generate the new complex {Y(eta-3-C3H5)[N(SiMe2CH2PMe2)2]}2(mu-Cl)2. Careful product analysis showed that the identity of the magnesium byproduct was in fact the bis(amide) derivative Mg[N(SiMe2CH2PMe2)2]2; improved procedures utilize the diallylmagnesium compound Mg(C3H5)2.(dioxane), which obviates the production of MgCl2. Attempts to introduce hydrocarbyl groups on the Mono(ligand) derivative YCl2[N(SiMe2CH2PMe2)2] by control Of stoichiometry have so far failed, with the exception of the formation of the bis(allyl) derivative [Y(eta-3-C3H5)2[N(SiMe2CH2PMe2)2] by the reaction with Mg(C3H5)2.(dioxane); this bis(allyl) derivative acts as a catalyst precursor for the polymerization of ethylene.