Synthesis, structure and ethylene polymerization of group 4 complexes with phosphinoamide ligands

Group 4 complexes containing diphosphinoamide ligands [Ph 2 PNR] 2 MCl 2 (3: R = t Bu, M = Ti; 4: R = t Bu, M = Zr; 5: R = Ph, M = Ti; 6: R = Ph, M = Zr) were prepared by the reaction of MCl 4 (M = Ti; Zr) with the corresponding lithium phosphinoamides in ether or THF. The structure of [Ph 2 PN t Bu] 2 TiCl 2 (3) was determined by X‐ray crystallography. The phosphinoamides functioned as η 2 ‐coordination ligands in the solid state and the TiN bond length suggests it is a simple single bond. In the presence of modified methylaluminoxane or i ‐Bu 3 Al/Ph 3 BC(C 6 F 5 ) 4 , catalytic activity of up to 59.5 kg PE/mol cat h bar was observed. Copyright © 2005 John Wiley & Sons, Ltd.