Synthesis, characterization, and marked polymerization selectivity characteristics of binuclear phenoxyiminato organozirconium catalysts

The new binuclear phenoxyiminato zirconium complex {1,7-(O)(2)C10H4-2,7-[CH=N(2,6(t)Pr(2)C(6)H(3))] 2}Zr2Cl6(THF)(2)(Fl(2)-Zr-2) polymerizes ethytene with greater activity (similar to 8(x)) than the mononuclear analogue. Also, this catalyst produces high molecular weight ethylene + 1-hexene copolymers, while the mononuclear analogue yields only traces of copolymer under identical conditions. This ability to produce copolymers suggests cooperativity between the two Zr centers which promotes 1-hexene co-enchainment.