1395897-97-8Relevant articles and documents
Bimetallic zirconium amine bis(phenolate) polymerization catalysts: Enhanced activity and tacticity control for polyolefin synthesis
Radlauer, Madalyn R.,Agapie, Theodor
supporting information, p. 3247 - 3250 (2014/08/05)
Binucleating multidentate amine bis(phenolate) ligands with rigid terphenyl backbones were designed to support two zirconium centers locked in close proximity. Polymerizations of propylene or 1-hexene with the synthesized bimetallic precatalysts resulted in polymers with significantly higher isotacticity (up to 79% mmmm) in comparison to the stereoirregular polymers produced with previously reported Cs-symmetric monometallic analogues. The bimetallic precatalysts also display higher activity (up to 124 kg of poly(1-hexene) (mmol of Zr)-1 h-1), in comparison to the monometallic analogues, and among the highest activities reported for nonmetallocene catalysts. The stereocontrol is consistent with a bimetallic mechanism involving remote steric interactions with the ligand sphere of the second metal center.