Synthesis and characterization of Ni (II) complexes supported by phenoxy/naphthoxy‐imine ligands with pendant <i>N</i>‐ and <i>O</i>‐donor groups and their use in ethylene oligomerization

Oliveira, Lucilene L. de; Silva, S.M. da; Casagrande, Adriana C. A.; Stieler, Rafael; Casagrande, Osvaldo L.

doi:10.1002/aoc.4414

Cited by 8 publications

(5 citation statements)

References 94 publications

(120 reference statements)

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“…One of the strategies employed with monoanionic tridentate ligands is to introduce an additional donor group into bidentate monoanionic ligands known to possess interesting properties as regards the oligomerization of ethylene. 140 Wang et al 141 reported tridentate phenoxy-imine based nickel complexes 53 (Figure 29). The complex 53 transforms ethylene into butenes as the main product in the presence of MAO.…”

Section: Tridentate Monoanionic Ligands Llxmentioning

confidence: 99%

“…In presence of ethylene, the nickel(II) complexes 54 activated by AlEtCl 2 predominantly produce butenes and hexenes as the main products with good activity (Table 6). Casagrande et al 140 studied the impact of replacing the phenoxy moiety with a naphthoxy moiety in a phenoxy-imine based nickel catalyst bearing a pendant oxygen group on the oligomerization of ethylene 55a−b (Figure 29). All complexes are active in the oligomerization of ethylene when activated by MAO.…”

Section: Tridentate Monoanionic Ligands Llxmentioning

confidence: 99%

“…Research into new nickel-based complexes capable of selectively oligomerizing ethylene to alpha-oligomers led to the development of ligands offering a wide diversity of structures, such as tridentate ligands. One of the strategies employed with monoanionic tridentate ligands is to introduce an additional donor group into bidentate monoanionic ligands known to possess interesting properties as regards the oligomerization of ethylene …”

Section: Ligand Design Approach For Homogeneous Ethylene Oligomerizat...mentioning

confidence: 99%

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Nickel Catalyzed Olefin Oligomerization and Dimerization

et al. 2020

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Brought to life more than half a century ago and successfully applied for high-value petrochemical intermediates production, nickel-catalyzed olefin oligomerization is still a very dynamic topic, with many fundamental questions to address and industrial challenges to overcome. The unique and versatile reactivity of nickel enables the oligomerization of ethylene, propylene and butenes into a wide range of oligomers that are highly sought-after in numerous fields to be controlled. Interestingly, both homogeneous and heterogeneous nickel catalysts have been scrutinized and employed to do this. This rare specificity encouraged us to interlink them in this review so as to open up opportunities for further catalyst development and innovation. An in-depth understanding of the reaction mechanisms in play is essential to being able to fine-tune the selectivity and achieve efficiency in the rational design of novel catalytic systems. This review thus provides a complete overview of the subject, compiling the main fundamental/industrial milestones and remaining challenges facing homogeneous/heterogeneous approaches as well as emerging catalytic concepts, with a focus on the last 10 years.

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Section: Tridentate Monoanionic Ligands Llxmentioning

confidence: 99%

Section: Tridentate Monoanionic Ligands Llxmentioning

confidence: 99%

Section: Ligand Design Approach For Homogeneous Ethylene Oligomerizat...mentioning

confidence: 99%

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Nickel Catalyzed Olefin Oligomerization and Dimerization

et al. 2020

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“…Reducing the temperature from 10°C to 0°C leads to similar activity [TOF = 19.9 × 10 3 (mol ethylene) (mol Ni) −1 h −1 ] and selectivity (95.2%) for 1-butene. [37] On the basis of these preliminary results, MAO was selected to investigate the effect of the [Al/Ni] molar ratio on the TOF and selectivity for the production of 1-butene. However, despite the low activity at 20°C and 30°C, Ni1 still operates with good selectivity for 1-butene production (94.6 and 91.9%).…”

Section: Ethylene Oligomerization Studiesmentioning

confidence: 99%

Pyrazolyl‐phosphinoyl nickel (II) complexes: synthesis, characterization and ethylene dimerization studies

Junges

Dresch

Costa

et al. 2019

Applied Organom Chemis

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A series of new nickel (II) complexes of general formula [NiBr 2 (N,O) 2 ] (Ni1-Ni5) based on bidentate pyrazolyl-phosphinoyl ligands were prepared and characterized by IR spectroscopy, elemental analysis, high-resolution mass spectrometry (HRMS), and X-ray crystallography for Ni1. X-ray crystallographic analyses of Ni1 revealed a six-coordinate species, in which Ni (II) lies in an octaedral environment. The nickel center is chelated by two pyrazolyl-phosphinoyl ligands with the two bromide ligands occupying mutually trans positions. Upon activation with methylaluminoxane (MAO), all nickel complexes were able to oligomerize ethylene with turnover frequencies (TOFs) varying from 5.0 to 16.6 × 10 3 (mol ethylene) (mol Ni) −1 h −1 producing selectively 1-butene (91.0-95.5 wt%). The substitution on the pyrazolyl group and the length of the backbone chain play a significant role in the catalytic activity. The use of MAO/TMA (1:1) or MAO/TiBA (1:1) instead of MAO drastically reduced the activities. The TMA content has no significant influence on the selectivity. However, the use of TiBA leads to a reduction of 1-butene (from 94.9 to 71.0 wt%) and an improvement in the hexene production (from 1.5 to 23.3 wt%). Under optimized reaction conditions (10°C, 20 min, 20 bar ethylene, [Al/Ni] = 600), Ni1/MAO catalytic system yielded TOF = 24.7 × 10 3 (mol ethylene) (mol Ni) −1 h −1 with good selectivities for α-C4 (94.9 wt%).

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“…These findings are in line with ours previously reported studies involving nickel catalytic systems. [52,53] Thus, considering the high activity and selectivity for 1-butene production, MAO was chosen for the optimization process varying some oligomerization parameters such as temperature, lifetime, and the amount of cocatalyst.…”

Section: Ethylene Oligomerizationmentioning

confidence: 99%

Oligomerization of ethylene promoted by methylaluminoxane activated arylchalcogenyl‐sulfonate nickel(II) complexes

Costa

Lopes

Oliboni

et al. 2022

Applied Organom Chemis

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and the synthesis and ethylene reactivity of two new nickel complexes [NiCl (py)(E,SO)] (Ni1, E = Se; Ni2, E = S) are reported. The minimum energy structures of the complexes were determined by density functional theory (DFT) calculations. For both compounds, the triplet and singlet 1 structures (with Cl trans to chalcogen) are higher in energy compared with singlet 2 (with Cl cis to chalcogen). Under initial catalytic condition (MAO, [Al/Ni] = 300, time = 20 min, T = 30 C) complex Ni1 oligomerizes ethylene with turnover frequencies (TOF) of 32.6 Â 10 3 (mol ethylene) (mol Ni) À1 (h) À1 with 81.3% of 1-butene production. The use of different cocatalyst systems (MAO/TMA or MAO/TiBA in an equimolar ratio) led to lower activities and poor selectivity for 1-C 4 . Under optimized reaction conditions (MAO, [Al/Ni] = 600, time-= 20 min, T = 30 C), the phenylthionyl complex Ni2 was 1.7 times more active than the phenylselenyl analog, with TOF of 72.3 Â 10 3 (mol ethylene) (mol Ni) À1 (h) À1 with 84.3% of 1-butene selectivity. DFT calculations suggest that the lowest lowest unoccupied molecular orbital (LUMO) energy and highest natural charge at the Ni center could be associated to the higher activity of Ni2 compared with the phenylselenyl analog Ni1.

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Synthesis and characterization of Ni (II) complexes supported by phenoxy/naphthoxy‐imine ligands with pendant N‐ and O‐donor groups and their use in ethylene oligomerization

Cited by 8 publications

References 94 publications

Nickel Catalyzed Olefin Oligomerization and Dimerization

Nickel Catalyzed Olefin Oligomerization and Dimerization

Pyrazolyl‐phosphinoyl nickel (II) complexes: synthesis, characterization and ethylene dimerization studies

Oligomerization of ethylene promoted by methylaluminoxane activated arylchalcogenyl‐sulfonate nickel(II) complexes

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