Preparation of chromium catalysts bearing bispyridylamine and its performance in ethylene oligomerization

Wang, Jun; Liu, Jinyi; Chen, Liduo; Lan, Tianyu; Wang, Libo

doi:10.1007/s11243-019-00333-3

Cited by 7 publications

(6 citation statements)

References 38 publications

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“…It should be noted that both the Cr source and solvent type have the local influences on catalytic ethylene tri/tetramerization . Unlike complex 7 bearing the ligand 2 system, Cr(acac) 3 or CrCl 3 (THF) 3 was stoichiometrically mixed with ligand 2 for preparing the in situ catalysts and then were subjected to evaluating the catalytic ethylene tri/tetramerization performance, as shown in Figure a.…”

Section: Resultsmentioning

confidence: 99%

“…Based on these results, it can be concluded that high ethylene pressure can facilitate ethylene insertion into metallacycloheptane, which leads to the formation of a metallacyclononane reaction intermediate. 44 Next, the effects of reaction temperatures (40,45,50,55, and 60 °C) with a complex 7/MAO system at 45 bar were further investigated. As shown in Figure 2b, the catalytic activity of the complex 7/MAO system exhibited volcano shape, and the highest catalytic activity of 435.2 kg/(g•Cr•h) and the lowest PE content of 0.2% were obtained at 45 °C.…”

Section: Effects Of Reaction Parameters On Ethylenementioning

confidence: 99%

“…44,49 It should be noted that both the Cr source and solvent type have the local influences on catalytic ethylene tri/tetramerization. 50 Unlike complex 7 bearing the ligand 2 system, Cr(acac) 3 or CrCl 3 (THF) 3 was stoichiometrically mixed with ligand 2 for preparing the in situ catalysts and then were subjected to evaluating the catalytic ethylene tri/tetramerization performance, as shown in Figure 4a. Experimental results indicated that upon activation by MAO, the activity of complex 7 was remarkably superior to that of the in situ mixed system for ligand 2 with Cr(acac) 3 or CrCl 3 (THF) 3 (Table 3, entries 10 and 12−13).…”

Section: Effects Of Reaction Parameters On Ethylenementioning

confidence: 99%

See 2 more Smart Citations

Chromium-Based Complexes Bearing Aminophosphine and Phosphine–Imine–Pyrryl Ligands for Selective Ethylene Tri/Tetramerization

Liu

Liu²,

Yang³

et al. 2023

ACS Omega

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A series of Cr-based complexes 6−10 bearing aminophosphine (P,N) ligands Ph 2 P−L−NH 2 [L = CH 2 CH 2 (1), L = CH 2 CH 2 CH 2 (2), and L = C 6 H 4 CH 2 (3)] and phosphine−imine− pyrryl (P,N,N) ligands 2-(Ph 2 P−L−N�CH)C 4 H 3 NH [L = CH 2 CH 2 CH 2 ( 4) and L = C 6 H 4 CH 2 (5)] were prepared, and their catalytic properties were examined for ethylene tri/tetramerization. Xray crystallographic analysis of complex 8 indicated the κ 2 -P,N bidentate coordination mode at the Cr(III) center and the distorted octahedral geometry of monomeric P,N−CrCl 3 . Upon activation by methylaluminoxane (MAO), complexes 7−8 bearing P,N (PC 3 N backbone) ligands 2−3 showed good catalytic reactivity for ethylene tri/tetramerization. On the other hand, complex 6 bearing the P,N (PC 2 N backbone) ligand 1 was found active for non-selective ethylene oligomerization, while complexes 9−10 bearing P,N,N ligands 4−5 only produced polymerization products. In particular, the high catalytic activity of 458.2 kg/(g•Cr•h), excellent selectivity of 90.9% (1-hexene and 1-octene combined), and extremely low PE content of 0.1% were obtained with complex 7 in toluene at 45 °C and 45 bar. These results suggest that rational control of P,N and P,N,N ligand backbones, including a carbon spacer and rigidity of a carbon bridge, can lead to the high-performance catalyst for the ethylene tri/tetramerization process.

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Section: Resultsmentioning

confidence: 99%

Section: Effects Of Reaction Parameters On Ethylenementioning

confidence: 99%

Section: Effects Of Reaction Parameters On Ethylenementioning

confidence: 99%

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Chromium-Based Complexes Bearing Aminophosphine and Phosphine–Imine–Pyrryl Ligands for Selective Ethylene Tri/Tetramerization

Liu

Liu²,

Yang³

et al. 2023

ACS Omega

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“…42) and chromium complexes for ethylene oligomerization. 209 With toluene as the solvent, the catalytic activity when using 345 reached 5.63 kg gCr −1 h −1 and the selectivity toward C 8 was very good (55.34%). In general, bis- N -amine ligands have a certain activity for ethylene oligomerization, but they are far from competitive with bisphosphine ligands.…”

Section: Role Of Ligandsmentioning

confidence: 96%

Selective ethylene tetramerization: an overview

Hao

Alam

Jiang

et al. 2023

Inorg. Chem. Front.

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“…In addition, researchers could also adjust the steric hindrance by changing the ligand substituents. [23][24][25][26] In the meantime, iron-based catalysts are favored by many researchers for their advantages, [27][28][29] including better catalytic activity, [30][31][32][33][34][35] higher selectivity, [36][37][38][39][40] and good spatial variability in the spacial structure of ligands [41][42][43][44] etc.…”

Section: Introductionmentioning

confidence: 99%

Research progress of iron-based catalysts for selective oligomerization of ethylene

Wang

et al. 2020

RSC Adv.

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Preparation of chromium catalysts bearing bispyridylamine and its performance in ethylene oligomerization

Cited by 7 publications

References 38 publications

Chromium-Based Complexes Bearing Aminophosphine and Phosphine–Imine–Pyrryl Ligands for Selective Ethylene Tri/Tetramerization

Chromium-Based Complexes Bearing Aminophosphine and Phosphine–Imine–Pyrryl Ligands for Selective Ethylene Tri/Tetramerization

Selective ethylene tetramerization: an overview

Research progress of iron-based catalysts for selective oligomerization of ethylene

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