Titanium complexes with β-ketoiminate chelate ligands for ethylene polymerization: The significant influence of substituents on structures and catalytic activities

Xie, Guangyong; Li, Yuxue; Qian, Chuan

doi:10.1016/j.inoche.2009.06.012

Cited by 27 publications

(7 citation statements)

References 31 publications

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“…For instance, the most active phenoxyimine catalysts (FI) are based on ligands with fully or partially fluorinated aromatic rings [20,21] ; a similar positive effect of fluorine atoms was observed in the series of mono(β-diiminato)titanium trichloride complexes by Xie and co-workers. [22][23][24] The introduction of a stable bis-(CF 3 )-carbinol fragment into various phenols allowed us to obtain a series of highly active in olefin (co) polymerization titanium complexes. [25][26][27][28] The successful use of ligands containing bis-(CF 3 )-carbinol fragment to prepare highly active olefin polymerization catalysts has been provided previously.…”

Section: Synthesis and Characterization Of Ligands And Coordination C...mentioning

confidence: 99%

Olefin polymerization behavior of titanium(IV) alkoxo complexes with fluorinated diolate ligands: The impact of the chelate ring size and the nature of organoaluminum compounds

Тuskaev

Гагиева

Kurmaev

et al. 2020

Applied Organom Chemis

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Titanium(IV) coordination compounds are effectively used as precatalysts for ethylene polymerization and copolymerization with other olefins. New titanium(IV) complexes 3b-d with ligands containing two diphenylcarbinol fragments linked by the perfluorinated hydrocarbon units-CF 2or-C 2 F 4were synthesized. The structures of complexes 3b and 3d were determined by X-ray diffraction. Titanium atoms in 3b have a distorted trigonal-bipyramidal coordination environment while spiro-complex 3d is characterized by tetrahedral molecular geometry. The catalytic behavior of complexes activated by mixtures of Bu 2 Mg and alkylaluminium chlorides from among Me 2 AlCl, Et 2 AlCl, EtAlCl 2 , and Et 3 Al 2 Cl 3 were studied. The resulting catalytic systems catalyze ethylene polymerization to afford ultra-high molecular weight polyethylene, suitable for modern processing methods, and the solvent-free solid state formation of super high-strength (1.37-2.75 GPa) and high-modulus (up to 138 GPa) oriented film tapes. The same catalytic systems catalyze ethylene copolymerization with 1-hexene to afford high molecular weight semicrystalline elastomeric polymers containing up to 20% of comonomer units.

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Section: Synthesis and Characterization Of Ligands And Coordination C...mentioning

confidence: 99%

Olefin polymerization behavior of titanium(IV) alkoxo complexes with fluorinated diolate ligands: The impact of the chelate ring size and the nature of organoaluminum compounds

Тuskaev

Гагиева

Kurmaev

et al. 2020

Applied Organom Chemis

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“…ε-Caprolactone, cyclohexene oxide, and propylene oxide were purchased from Acros Organics, stirred over CaH 2 for 24 h, and distilled. Ketimines were prepared by following the literature procedures . Tetrahydrofuran, toluene, and hexane were distilled fresh from Na/benzophenone ketyl before using.…”

Section: Methodsmentioning

confidence: 99%

“…To a stirred solution of the corresponding ketimine in toluene was added n -BuLi at −78 °C. The mixture was warmed to room temperature and stirred for 6 h. The reaction mixture was again cooled to −78 °C, and a solution of chlorodiphenylphosphine in toluene was added.…”

Section: Methodsmentioning

confidence: 99%

CO₂/Epoxide Coupling and the ROP of ε-Caprolactone: Mg and Al Complexes of γ-Phosphino-ketiminates as Dual-Purpose Catalysts

et al. 2018

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γ-Phosphino-ketimines Ph 2 PC[C(Me)O][C(Me)NAr] (Ar = 2,6-diisopropylphenyl, L 1 H; Ar = 2,6-difluorophenyl, L 2 H) were synthesized by treating deprotonated ketimines with PPh 2 Cl. Their Mg complexes [(L 1 ) 2 (THF)Mg] (1) and [(L 2 ) 2 (THF) 2 Mg] (2) were obtained in excellent yields from a reaction between LH and di-nbutylmagnesium in THF. Addition of a slight excess of trimethylaluminum to LH in toluene yielded the Al complexes [L 1 AlMe 2 ] ( 3) and [L 2 AlMe 2 ] (4). Complexes 1 and 3 displayed high catalytic activity in the synthesis of cyclic carbonates from CO 2 and epoxides and also in the ring-opening polymerization (ROP) of ε-caprolactone. However, complexes 2 and 4, which contain fluoro substituents, showed poor activity in the synthesis of cyclic carbonates and could not initiate the ROP reaction. The pentacoordinated Mg complex 1 was found to be a better catalyst than the aluminum complex 3. It was also observed that the complexes 1 and 3 were more efficient than the unsubstituted ketiminate complexes reported in the literature.

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“…Among these, early transition non-metallocene binuclear complexes have rarely been reported. Our lab has been focused on developing novel non-metallocene catalysts through modification of the coordination environment of the central metals by using the steric/electronic effect of the substituents [49,50,51,52,53,54,55,56]. Recently we have successfully prepared LLDPE from ethylene in a single reactor using non-metallocene titanium complex as the copolymerization catalyst of a tandem dual-functional catalyst systems [57,58].…”

Section: Introductionmentioning

confidence: 99%

Methylene-Bridged Tridentate Salicylaldiminato Binuclear Titanium Complexes as Copolymerization Catalysts for the Preparation of LLDPE through [Fe]/[Ti] Tandem Catalysis

Luo

et al. 2019

Polymers

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A novel tandem catalysis system consisted of salicylaldiminato binuclear/mononuclear titanium and 2,6-bis(imino)pyridyl iron complexes was developed to catalyze ethylene in-situ copolymerization. Linear low-density polyethylene (LLDPE) with varying molecular weight and branching degree was successfully prepared with ethylene as the sole monomer feed. The polymerization conditions, including the reaction temperature, the Fi/Ti molar ratio, and the structures of bi- or mononuclear Ti complexes were found to greatly influence the catalytic performances and the properties of obtained polymers. The polymers were characterized by differential scanning calorimetry (DSC), high temperature gel permeation chromatography (GPC) and high temperature 13C NMR spectroscopy, and found to contain ethyl, butyl, as well as some longer branches. The binuclear titanium complexes demonstrated excellent catalytic activity (up to 8.95 × 106 g/molTi·h·atm) and showed a strong positive comonomer effect when combined with the bisiminopyridyl Fe complex. The branching degree can be tuned from 2.53 to 22.89/1000C by changing the reaction conditions or using different copolymerization pre-catalysts. The melting points, crystallinity and molecular weights of the products can also be modified accordingly. The binuclear complex Ti2L1 with methylthio sidearm showed higher capability for comonomer incorporation and produced polymers with higher branching degree and much higher molecular weight compared with the mononuclear analogue.

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Titanium complexes with β-ketoiminate chelate ligands for ethylene polymerization: The significant influence of substituents on structures and catalytic activities

Cited by 27 publications

References 31 publications

Olefin polymerization behavior of titanium(IV) alkoxo complexes with fluorinated diolate ligands: The impact of the chelate ring size and the nature of organoaluminum compounds

Olefin polymerization behavior of titanium(IV) alkoxo complexes with fluorinated diolate ligands: The impact of the chelate ring size and the nature of organoaluminum compounds

CO₂/Epoxide Coupling and the ROP of ε-Caprolactone: Mg and Al Complexes of γ-Phosphino-ketiminates as Dual-Purpose Catalysts

Methylene-Bridged Tridentate Salicylaldiminato Binuclear Titanium Complexes as Copolymerization Catalysts for the Preparation of LLDPE through [Fe]/[Ti] Tandem Catalysis

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Titanium complexes with β-ketoiminate chelate ligands for ethylene polymerization: The significant influence of substituents on structures and catalytic activities

Cited by 27 publications

References 31 publications

Olefin polymerization behavior of titanium(IV) alkoxo complexes with fluorinated diolate ligands: The impact of the chelate ring size and the nature of organoaluminum compounds

Olefin polymerization behavior of titanium(IV) alkoxo complexes with fluorinated diolate ligands: The impact of the chelate ring size and the nature of organoaluminum compounds

CO2/Epoxide Coupling and the ROP of ε-Caprolactone: Mg and Al Complexes of γ-Phosphino-ketiminates as Dual-Purpose Catalysts

Methylene-Bridged Tridentate Salicylaldiminato Binuclear Titanium Complexes as Copolymerization Catalysts for the Preparation of LLDPE through [Fe]/[Ti] Tandem Catalysis

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CO₂/Epoxide Coupling and the ROP of ε-Caprolactone: Mg and Al Complexes of γ-Phosphino-ketiminates as Dual-Purpose Catalysts