Synthesis and crystal structures of novel β-diketiminato-lithium, iron, cobalt, nickel, zirconium complexes and their catalytical behaviors in polymerization of ethylene

Treatment of azaallyl-lithium [ LiN(R)C(Bu t )C HR] with equal portion of 1-piperidinecarbonitrile gave mix-substituted bdiketiminato-lithium 2. Double ratio of 2 with FeCl2, CoCl2 and NiCl2/6H2O yielded the b-diketiminate iron 3, cobalt 4, nickel 5 ,o r equivalent of ZrCl4 led to zirconium complex 6, respectively. The structural features of these complexes were described, and the catalytical behaviors of the complexes 3 � /6 for the polymerization of ethylene were investigated. # 2002 Elsevier Science B.V. All rights reserved.