Structure–property-relationship studies with ethylene polymerization catalysts of Ti, Zr and V containing heterocyclic ligands

Elagab, Hamdi Ali; Alt, Helmut G.

doi:10.1016/j.ica.2015.08.002

Cited by 13 publications

(2 citation statements)

References 34 publications

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“…The best result 7300 kgPE/(molV•h) shows the catalyst with the ligand L1, 5800 kgPE/(molV•h) for the complex L3 and 4500 kgPE/(molV•h) for the complex L2 (Table 1, items 5, 16 and 10). These differences can be explained by a steric effect, which for the vanadium catalysts often results in changes of activity [21,[37][38][39]. The obtained polyethylene has the melting temperature and crystallinity degree in the range of 123-142 • C and 49-75%, respectively, and higher values of these parameters were obtained at lower activator/catalyst molar ratio and in the presence of ETA reactivator.…”

Section: Ethylene Polymerizationmentioning

confidence: 99%

Titanium and Vanadium Catalysts with 2-Hydroxyphenyloxazoline and Oxazine Ligands for Ethylene-Norbornene (co)Polymerization

et al. 2019

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A series of titanium and vanadium complexes with oxazoline 2-(4,5-dihydro-1,3-oxazol-2-yl)phenol (L1), 2-(4-methyl-4,5-dihydro-1,3-oxazol-2-yl)phenol (L2), and oxazine 2-(5,6-dihydro-4H-1,3-oxazin-2-yl)phenol (L3) ligands were synthesized, and their structures were determined by NMR and MS methods as (L)2MtCl2. The vanadium complexes were found to be highly active in ethylene (7300 kgPE/(molV·h)) and ethylene/norbornene (5300 kgCop/(molV·h)) (co)polymerization. The polyethylene characteristics were melting temperature (123–142 °C), crystallinity degree (49–75%), molecular weight (5.7–8.5 × 105 g/mol), molecular weight distribution (1.5–2.4). The ethylene-norbornene (E-NB) copolymer characteristics were molecular weight (2.6–0.9 × 105 g/mol), molecular weight distribution (1.6–2.2), glass transition temperature (4–62 °C), norbornene incorporation (12.3–30.1 mol%) at initial concentration (0.5–1.5 mol/L). The microstructure of E-NB copolymers depends on the catalyst applied with the highest diads content for the (L3)2VCl2 and triads for the (L2)2VCl2 complexes.

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Section: Ethylene Polymerizationmentioning

confidence: 99%

Titanium and Vanadium Catalysts with 2-Hydroxyphenyloxazoline and Oxazine Ligands for Ethylene-Norbornene (co)Polymerization

et al. 2019

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“…The vanadium complexes of bis(benzimidazole)amine tridentate ligands [N, N, N], were reported as active ethylene polymerization catalysts after activation with simple alkylaluminum compounds 31 2,6-Bis(2-benzimidazolyl)pyridine zirconium dichloride / MAO polymerizes methylacrylate 32 Recently, [33][34][35][36][37][38][39] we reported the ethylene polymerization activity of benzimidazole, benzothiazole, benzoxazole and 2-(benzimidazolyl) pyridine titanium zirconium and vanadium complexes. Herein we report on the effect of hetero atom on the activity of zirconium, complexes of bis (benzimidazole), benzothiazole, and benzoxazole), and their behaviour towards ethylene polymerization after activation with methylaluminoxane (MAO).…”

Section: Introductionmentioning

confidence: 99%

Ti (IV) Complexes of Some Heterocyclic Ligands Synthesis, Characterization and Ethylene Polymerization Activity

Elagab¹

2016

Orient. J. Chem

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ABSTRACT31 complexes of bis -(benzimidazole, benzothiazole and benzoxazole) compounds with Ti (IV) metal centers were synthesized, characterized, activated with methylalumoxane (MAO) and then tested for catalytic ethylene polymerization. The activities of the various catalysts were found to be functions of the hetero atoms in the ligand frameworks. The highest activity was obtained with 39 / MAO (573 kg PE / mol cat. h). The produced polyethylenes showed high molecular weights (up to 1.5 × 10 6 g/mol) and broad molecular weight distributions (PD = 65). This could result from different interactions of the MAO counterion with the heteroatoms of the catalyst ligand generating different active sites.

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Bis(4‐benzhydryl‐benzoxazol‐2‐yl)methane – from a Bulky NacNac Alternative to a Trianion in Alkali Metal Complexes

Kretsch

Kreyenschmidt

Schillmöller

et al. 2021

Chemistry A European J

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A novel sterically demanding bis(4‐benzhydryl‐benzoxazol‐2‐yl)methane ligand 6 (4−BzhH2BoxCH2) was gained in a straightforward six‐step synthesis. Starting from this ligand monomeric [M(4‐BzhH2BoxCH)] (M=Na (7), K (81)) and dimeric [{M(4‐BzhH2BoxCH)}2] (M=K (82), Rb (9), Cs (10)) alkali metal complexes were synthesised by deprotonation. Abstraction of the potassium ion of 8 by reaction with 18‐crown‐6 resulted in the solvent separated ion pair [{(THF)2K@(18‐crown‐6)}{bis(4‐benzhydryl‐benzoxazol‐2‐yl)methanide}] (11), including the energetically favoured monoanionic (E,E)‐(4‐BzhH2BoxCH) ligand. Further reaction of 4−BzhH2BoxCH2 with three equivalents KH and two equivalents 18‐crown‐6 yielded polymeric [{(THF)2K@(18‐crown‐6)}{K@(18‐crown‐6)K(4‐BzhBoxCH)}]n (n→∞) (12) containing a trianionic ligand. The neutral ligand and herein reported alkali complexes were characterised by single X‐ray analyses identifying the latter as a promising precursor for low‐valent main group complexes.

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Structure–property-relationship studies with ethylene polymerization catalysts of Ti, Zr and V containing heterocyclic ligands

Cited by 13 publications

References 34 publications

Titanium and Vanadium Catalysts with 2-Hydroxyphenyloxazoline and Oxazine Ligands for Ethylene-Norbornene (co)Polymerization

Titanium and Vanadium Catalysts with 2-Hydroxyphenyloxazoline and Oxazine Ligands for Ethylene-Norbornene (co)Polymerization

Ti (IV) Complexes of Some Heterocyclic Ligands Synthesis, Characterization and Ethylene Polymerization Activity

Bis(4‐benzhydryl‐benzoxazol‐2‐yl)methane – from a Bulky NacNac Alternative to a Trianion in Alkali Metal Complexes

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