Novel zirconium complexes of amine bis(phenolate) ligands. Remarkable reactivity in polymerization of hex-1-ene due to an extra donor arm

Zirconium complexes of two dianionic amine bis(phenolate) ligands have been synthesized, their X-ray structures solved, and their activity as hex-1-en e polymerization catalysts studied; upon treatment with B(C6F5)(3), an octa hedral [ONNO]Zr(CH2Ph)(2) complex, having an extra N-donor group on a side arm, shows exceptionally high polymerization activity and yields a high mol ecular weight poly(hex-1-ene), whereas a related pentacoordinate [ONO]Zr(CH 2Ph)(2) complex, having no extra donor group, shows only poor activity as a polymerization catalyst.