Nickel Phosphine Complexes: Synthesis, Characterization, and Behavior in the Polymerization of 1,3-Butadiene

Several nickel dichloride phosphine complexes have been synthesized, their crystalline structure determined, and their behavior, in combination with methylaluminoxane, in the polymerization of butadiene has been examined. High-cis polybutadienes were consistently obtained, regardless of the nature of the phosphine coordinated to the metal and the methylaluminoxane/Ni molar ratio used, contrary to what was previously observed in the polymerization of butadiene with analogous cobalt phosphine complexes, in which catalytic selectivity was found to be strongly influenced by these two factors. An interpretation for such different behavior is provided.