UV–visible spectroscopy for zirconocene activation by MAO in olefin polymerization: activity versus wavenumber

Alonso‐Moreno, Carlos; Carrión, Pedro; Carrillo‐Hermosilla, Fernando; Antiñolo, Antonío; Otero, Antonío

doi:10.1002/aoc.1505

Cited by 5 publications

(3 citation statements)

References 30 publications

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“…The most part of authors who studied the UV and visible spectra of the metallocene catalytic polymerization systems [5,12] indicated that the products (1) and (2) were formed at room temperature rapidly (within less than 5 min). The slow formation of these products in the case of the Cp 4 Zr-MAO system (the absorbance maximum is achieved in 50-60 min at 60°C, see Fig.…”

Section: Spectra Of the Cp 4 Zr-mao System In The Uv And Visible Rangesmentioning

confidence: 99%

“…It was found [12] that the bathochromic shift in the electronic spectra of the studied metallocene catalytic systems for olefin polymerization was proportional to their activity.…”

Section: Introductionmentioning

confidence: 98%

“…Unlike NMR spectroscopy, spectroscopy in the UV-Visible range makes it possible to study metallocene catalytic systems of polymerization at low metallocene concentrations (for the NMR method, the sensitivity threshold is about 10 -3 mol/L) and high molar Al/Zr concentrations [12].…”

Section: Introductionmentioning

confidence: 99%

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Mechanism of the interaction of components in the metallocene catalytic systems containing titanium and zirconium tetracyclopentadienyls and methylaluminoxane

Седов

Matkovskiy

Кнерельман

et al. 2016

Reac Kinet Mech Cat

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The reactions of components of the catalytic systems (C 5 H 5 ) 4 Zr-MAO and (C 5 H 5 ) 4 Ti-MAO in the absence and in the presence of the monomer were studied in order to obtain information on the mechanism of polymerization and copolymerization of ethylene. It was shown that the reactions accompanied by a change in the coordination mode of the ligands in the metallocene complex, a change in the coordination number of the transition metal, and the reduction of the transition metal can occur in these systems. A mechanism for the interaction of components in the indicated catalytic systems was proposed on the basis of our results obtained by various physicochemical methods and literature data.

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Section: Spectra Of the Cp 4 Zr-mao System In The Uv And Visible Rangesmentioning

confidence: 99%

“…It was found [12] that the bathochromic shift in the electronic spectra of the studied metallocene catalytic systems for olefin polymerization was proportional to their activity.…”

Section: Introductionmentioning

confidence: 98%

See 1 more Smart Citation

Mechanism of the interaction of components in the metallocene catalytic systems containing titanium and zirconium tetracyclopentadienyls and methylaluminoxane

Седов

Matkovskiy

Кнерельман

et al. 2016

Reac Kinet Mech Cat

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Toward the Prediction of Activity in the Ethylene Polymerisation of ansa‐Bis(indenyl) Zirconocenes: Effect of the Stereochemistry and Hydrogenation of the Indenyl Moiety

et al. 2015

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A combined experimental and quantum chemical study has been performed on rac‐ and meso‐[Zr{1‐Me2Si(3‐η5‐C9H5Et)2}Cl2] (rac‐ and meso‐1) and their hydrogenated forms (rac‐ and meso‐2) to understand ligand effects and guide ligand design for more active ansa‐bis(indenyl) zirconocenes for the polymerisation of ethylene. The rac‐ansa‐zirconocene rac‐[Zr(1‐Me2Si{3‐Et‐(η5‐C9H9)}2)Cl2] (rac‐2) has been prepared and fully characterised by NMR spectroscopy and elemental analysis. The molecular structure of rac‐2 has also been determined by single‐crystal XRD. The behaviour of the catalysts was analysed in the polymerisation of ethylene and higher activities were obtained for rac‐1 and its hydrogenated form rac‐2. The influence of the stereochemistry and hydrogenation of the indenyl ligand on the experimental activities has been evaluated by computational studies. The differences along the reaction pathway are dominated by changes in the relative stabilities of the catalytic intermediates. A hybrid density functional B3LYP study, in the presence of toluene as the solvent, indicates that the rac forms give rise to more active species than their meso counterparts. The hydrogenation of the rac forms is a very promising approach to increase activities in polymerisation, in contrast to the meso forms. Finally, the global mechanism rate constants for the polymerisation reaction for each metallocene were calculated by using the thermodynamic formulation of transition‐state theory to complement the computational study.

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Grafting of the zirconium complexes [Zr(η5-C5H5){NC-amidine}Cl2] and [Zr(η5-C5H5)(NC-NacNac)Cl2] and the study of their behavior in ethylene polymerization

Cabrera

Villaseñor

Werlinger

et al. 2014

Journal of Molecular Catalysis A: Chemical

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UV–visible spectroscopy for zirconocene activation by MAO in olefin polymerization: activity versus wavenumber

Cited by 5 publications

References 30 publications

Mechanism of the interaction of components in the metallocene catalytic systems containing titanium and zirconium tetracyclopentadienyls and methylaluminoxane

Mechanism of the interaction of components in the metallocene catalytic systems containing titanium and zirconium tetracyclopentadienyls and methylaluminoxane

Toward the Prediction of Activity in the Ethylene Polymerisation of ansa‐Bis(indenyl) Zirconocenes: Effect of the Stereochemistry and Hydrogenation of the Indenyl Moiety

Grafting of the zirconium complexes [Zr(η5-C5H5){NC-amidine}Cl2] and [Zr(η5-C5H5)(NC-NacNac)Cl2] and the study of their behavior in ethylene polymerization

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