(Pyrazolyl)-(phosphinoyl)pyridine iron(II), cobalt(II) and nickel(II) complexes: Synthesis, characterization and ethylene oligomerization studies

Nyamato, George S.; Alam, Mohd Gulfam; Ojwach, Stephen O.; Akerman, Matthew P.

doi:10.1016/j.jorganchem.2015.02.015

Cited by 37 publications

(16 citation statements)

References 49 publications

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“…The activity and the content of longer chain oligomers were further increased when EtAlCl 2 was employed as cocatalyst. Nonetheless, activating the catalysts using EtAlCl 2 in toluene solvent produced predominantly alkylated‐toluenes of the pre‐formed oligomers according to the related literatures . The obtained result is in agreement with those of Nyamato and Ojwach .…”

Section: Evaluation Of the Metal Complexes As Catalysts For Ethylene supporting

confidence: 88%

“…[15][16][17] Especially in recent years, many nickel complexes with a novel ligand structure have been exploited. Nyamato et al 21 reported (Pyrazolyl)-(phosphinoyl)pyridine nickel(II) complexes as ethylene oligomerization catalysts. The result showed that when activated with ethylaluminum sesquichloride (EASC), the nickel precatalysts displayed good catalytic activity (up to 2.89 9 10 6 g/mol Ni h), and the oligomers was mainly C 4 .…”

Section: Introductionmentioning

confidence: 99%

“…In addition, a series of nickel halides bearing butyl‐(quinolin‐yliminomethyl)phenolate ligands were also synthesized by Sun et al On activation with Et 2 ClAl, all the nickel complexes exhibited high activity for ethylene oligomerization and the C 4 and C 6 were mainly oligomers. Nyamato et al reported (Pyrazolyl)‐(phosphinoyl)pyridine nickel(II) complexes as ethylene oligomerization catalysts. The results showed that the ligand structure, solvent, cocatalyst, and reaction conditions had significant influences on the catalytic activity and product compositions in the catalyst systems.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and Ethylene Oligomerization of Hyperbranched Salicylaldimine Nickel Complexes

Wang

Zhang

et al. 2016

Adv Polym Technol

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A series of new hyperbranched salicylaldimine nickel complexes were synthesized by the Schiff's base and the complexation reactions with 1.0 generation hyperbranched macromolecules, salicyladehyde and nickel chloride hexahydrate as materials by employing two-step synthesis and one-pot synthesis, respectively. The hyperbranched salicylaldimine ligands and the complexes were characterized by FT-IR, 1 H NMR, UV, and ESI-MS. All nickel complexes, activated with Methylaluminoxane, exhibited high activities for ethylene oligomerization (TOF = 1.92-4.93 g/mol Ni h) and showed good selectivities for the longer chain oligomers produced (36.35-60.33%). When activated with ethylaluminum dichloride, it was found that a tandem process occurred in which ethylene oligomerization was followed by Friedel-Crafts alkylation of the reaction solvent, toluene. On increasing the pressure of ethylene and Al/Ni ratio, the catalytic activities of precatalyst increased and the processes became more selective for the shorter oligomers. Not only the polymerized parameters but also the length of alkyl chain of the ligands influenced the catalytic activities and selectivities for the longer chain oligomers. The catalytic activities and selectivities for the longer chain oligomers declined with the increase in length of alkyl chain of ligand.

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Section: Evaluation Of the Metal Complexes As Catalysts For Ethylene supporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Synthesis and Ethylene Oligomerization of Hyperbranched Salicylaldimine Nickel Complexes

Wang

Zhang

et al. 2016

Adv Polym Technol

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“…The magnetic moments of complexes Fe1 – Fe3 were recorded as 5.60 BM, 5.15 BM and 5.43 BM respectively. These values are notably higher than the spin-only value of 4.90 BM for d 6 Fe( ii ) complexes at 300 K. Nevertheless, the values fall within the expected range of high spin Fe( ii ) complexes of 5.10–5.70 BM at 300 K. 39 Similarly, values of 3.26 BM, 3.99 BM and 3.59 BM for the Co( ii ) complexes Co1 – Co3 were recorded respectively, and are comparable to the spin-only value of 3.87 BM for high spin d 7 Co( ii ) complexes at 300 K. Finally, the magnetic moment values of 2.82 BM, 3.05 BM and 2.78 BM recorded for the Ni( ii ) complexes Ni1 – Ni3 respectively, were consistent with spin-only value of 2.83 BM and fall within the expected range of 2.90 BM–4.20 BM at 300 K for high-spin d 8 Ni( ii ) complexes. 40 One interesting import from the magnetic moments data is that the Fe( ii ) complexes showed relatively high observed magnetic moments, pointing to larger crystal field effects (orbital contribution) for the Fe( ii ) complexes in comparison to the Co( ii ) and Ni( ii ) complexes.…”

Section: Resultsmentioning

confidence: 58%

Structural and ethylene oligomerization studies of chelating (imino)phenol Fe(ii), Co(ii) and Ni(ii) complexes: an experimental and theoretical approach

et al. 2022

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“…Recently, the development of single site olefin polymerization is one of the hot topics in industrial polyolefins. Generally, to improve the polymerization catalytic performance, there are two desirable 2 of 15 methods: modification of ligands or transition metal substitutions [11][12][13][14][15][16][17]. Each fine-tuned ligand unit can offer various structural and electronic properties that influence the catalytic activity [13,18].…”

Section: Introductionmentioning

confidence: 99%

Straightforward Design for Phenoxy-Imine Catalytic Activity in Ethylene Polymerization: Theoretical Prediction

Chasing

Maitarad

et al. 2018

Catalysts

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The quantitative structure-activity relationship (QSAR) of 18 Ti-phenoxy-imine (FI-Ti)-based catalysts was investigated to clarify the role of the structural properties of the catalysts in polyethylene polymerization activity. The electronic properties of the FI-Ti catalysts were analyzed based on density functional theory with the M06L/6-31G** and LANL2DZ basis functions. The analysis results of the QSAR equation with a genetic algorithm showed that the polyethylene catalytic activity mainly depended on the highest occupied molecular orbital energy level and the total charge of the substituent group on phenylimine ring. The QSAR models showed good predictive ability (R2) and R2 cross validation (R2cv) values of greater than 0.927. The design concept is “head-hat”, where the hats are the phenoxy-imine substituents, and the heads are the transition metals. Thus, for the newly designed series, the phenoxy-imine substituents still remained, while the Ti metal was replaced by Zr or Ni transition metals, entitled FI-Zr and FI-Ni, respectively. Consequently, their polyethylene polymerization activities were predicted based on the obtained QSAR of the FI-Ti models, and it is noteworthy that the FI-Ni metallocene catalysts tend to increase the polyethylene catalytic activity more than that of FI-Zr complexes. Therefore, the new designs of the FI-Ni series are proposed as candidate catalysts for polyethylene polymerization, with their predicted activities in the range of 35,000–48,000 kg(PE)/mol(Cat.)·MPa·h. This combined density functional theory and QSAR analysis is useful and straightforward for molecular design or catalyst screening, especially in industrial research.

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(Pyrazolyl)-(phosphinoyl)pyridine iron(II), cobalt(II) and nickel(II) complexes: Synthesis, characterization and ethylene oligomerization studies

Cited by 37 publications

References 49 publications

Synthesis and Ethylene Oligomerization of Hyperbranched Salicylaldimine Nickel Complexes

Synthesis and Ethylene Oligomerization of Hyperbranched Salicylaldimine Nickel Complexes

Structural and ethylene oligomerization studies of chelating (imino)phenol Fe(ii), Co(ii) and Ni(ii) complexes: an experimental and theoretical approach

Straightforward Design for Phenoxy-Imine Catalytic Activity in Ethylene Polymerization: Theoretical Prediction

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