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Bimetallic Zirconium Amine Bis(phenolate) Polymerization Catalysts: Enhanced Activity and Tacticity Control for Polyolefin Synthesis.

Radlauer MR, Agapie T - Organometallics (2014)

Bottom Line: 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 C s -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.

View Article: PubMed Central - PubMed

Affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States.

ABSTRACT
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 C s -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.

No MeSH data available.


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Monometallic Zirconium Complexes
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cht1: Monometallic Zirconium Complexes


Bimetallic Zirconium Amine Bis(phenolate) Polymerization Catalysts: Enhanced Activity and Tacticity Control for Polyolefin Synthesis.

Radlauer MR, Agapie T - Organometallics (2014)

Monometallic Zirconium Complexes
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4216186&req=5

cht1: Monometallic Zirconium Complexes
Bottom Line: 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 C s -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.

View Article: PubMed Central - PubMed

Affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States.

ABSTRACT
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 C s -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.

No MeSH data available.


Related in: MedlinePlus