Zirconium indenylamido complexes: synthesis and reactivity: Crystal structure of [Zr(Ind)2(NC3H6)2]

Abstract Reactions of [ZrInd(NMe 2 ) 3 ] ( 1 ) with Me 3 SiCl afforded [ZrInd(NMe 2 ) 2 Cl] ( 2 ), [ZrInd(NMe 2 )Cl 2 ] ( 3 ) and [ZrIndCl 3 ] n ( 4 ) in high yields (≥90%). [ZrIndCl 3 (dme)] ( 5 ) was obtained either from 4 and dme or by a one-pot reaction from [ZrInd(NMe 2 ) 3 ], Me 3 SiCl and dme. Treatment of [ZrInd(NMe 2 ) 2 Cl] with LiMe gave [ZrInd(NMe 2 ) 2 Me] ( 6 ), and in similar reaction conditions [ZrInd 2 Me 2 ] ( 10 ) was obtained from [ZrInd(NMe 2 )Cl 2 ]. Whereas the reaction of 2 with LiN(H) t Bu produced {[ZrInd(NMe 2 ) 2 [N(H) t Bu]} ( 7 ), the addition of LiN(H) t Bu to [TiInd(NMe 2 ) 2 Cl] afforded [Ti(NMe 2 ) 2 (μ-N t Bu)] 2 ( 9 ) in quantitative yield. {TiInd(NMe 2 ) 2 [N(H) t Bu]} was identified by NMR as an intermediate in the synthesis of 9 , and two isomeric forms corresponding to the parallel ( 8a ) and perpendicular ( 8b ) orientations of the indenyl and N(H) t Bu ligands were characterised. The addition of an excess of azetidine to 1 gave [ZrInd 2 (NC 3 H 6 ) 2 ] ( 11 ), the molecular structure of which was determined by X-ray crystallography. Preliminary studies showed that 3 –methylaluminoxane (MAO) polymerises ethylene and propylene, whereas [TiInd(NMe 2 )Cl 2 ], 12 –MAO, only polymerises ethylene.