6533b82cfe1ef96bd128f611
RESEARCH PRODUCT
Synthesis, characterization and catalytic properties for olefin polymerization of two new dimeric zirconium(IV) complexes having diamine-bis(phenolate) and chloride ligands
Elwira BiszMarzena BiałekBartosz Zarychtasubject
chemistry.chemical_classificationpolyethyleneZirconiumEthyleneLigandProcess Chemistry and Technologychemistry.chemical_elementPolymerCatalysisCatalysispoly(1-octene)chemistry.chemical_compoundPolymerizationchemistryDiaminezirconium catalystPolymer chemistryTetrachloridediamine-bis(phenolate) ligandOrganic chemistryZiegler–Natta polymerizationdescription
Abstract Reaction of the zirconium tetrachloride with one equivalent of the sodium salt of the diamine bis (phenolate) ligand, L1H2 (Me2NCH2CH2N-(CH2-2-OH-3,5-tBu-C6H2)2) or L2H2 (Me2NCH2CH2N-(CH2-2-OH-3,5-tBu-C6H2)(CH2-2-OH-C6H4)) in the presence of air led to formation of [Lig1ZrCl]2(μ-O) and [Lig2ZrCl]2(μ-O), respectively. These novel oxo-bridged dinuclear zirconium complexes were characterized by elemental analysis, 1H NMR spectroscopy and by single-crystal X-ray diffraction. Their reactivities in polymerization of ethylene and 1-octene, upon activation with Al(iBu)3/Ph3CB(C6F5)4 and MAO, were examined. It was found that lack of t-Bu substituents on one phenolate ring cause a significant decrease in catalytic activity but leads to polymers with improving properties, i.e., to poly(1-olefin)s with significantly higher stereoregularity and polyethylenes with higher molecular weight. In addition, the interaction of the [Lig1ZrCl]2(μ-O) precursors with MAO and with the Me3Al activator was investigated by 1H NMR spectroscopy giving an insight into the catalyst transformations in the course of the polymerization reaction.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2015-08-01 | Applied Catalysis A : General : an International Journal Devoted to Catalytic Science and its Applications |