Synthesis of a novel triple-site diphosphinoamine (PNP) ligand and its applications in ethylene tetramerization

Mao, Guoliang; Ning, Yingnan; Hu, Wenbo; Li, ShanMing; Song, XianFeng; Niu, Bo; Jiang, Tao

doi:10.1007/s11434-008-0479-y

Cited by 21 publications

(22 citation statements)

References 18 publications

(11 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Contrary to the results reported previously [23], an increase in the Al/Cr molar ratio from 100 to 500 resulted in an increase in selectivity to 1-octene. The same results were found in the tetramerization of ethylene with triple-site diphosphinoamine (PNP)/Cr(III)/MAO [19]. …”

Section: The Effect Of Al/cr Molar Ratios On Catalytic Propertiessupporting

confidence: 73%

“…These include investigations into various single-site PNP ligands, wherein alkyl [10][11][12], cycloalkyl [13], ether [14], thioether, pyridyl tethers [15] and aryl [16,17] substituents attached to the N or P atom of the ligand backbone were synthesized and evaluated. Several dual-site PNP ligands [12,18] and a triple-site [19] were also found to have moderate activity and selectivity toward 1-octene in ethylene tetramerization.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Ethylene tetramerization with a highly active and long-lifetime trinuclear diphenylphosphinoamine/Cr(III)/MAO catalyst

et al. 2012

Self Cite

View full text Add to dashboard Cite

The synthesis and characterization of a novel trinuclear diphosphinoamine ligand 2 are reported. The ligand combined with Cr(III), activated with methylaluminoxane, lead to highly active and long-lifetime catalytic systems for the tetramerization of ethylene to form 1-octene. The effects of reaction temperature, reaction pressure, molar ratio of Al/Cr and bis(diphenylphosphino)amine/Cr on the catalytic activity and product selectivity were studied. Compared with its mononuclear analogue 1, ligand 2 showed a higher catalytic activity and longer lifetime for ethylene tetramerization in the presence of methylaluminoxane as cocatalyst. High molecular weight polyethylene was generated as a by-product with extremely broad molecular weight distributions. In recent years there has been a substantial acceleration in research activity concerned with homogeneous transition metal catalysts for ethylene oligomerization and polymerization. Chromium catalysts play an important role in both of these processes [1][2][3][4][5][6][7][8]. Since the first report of ethylene tetramerization to form 1-octene using Cr-bis(diphenylphosphino)amine (PNP) catalysts [9], numerous studies have investigated the relationship between ligand structure and catalytic properties. We were attracted by the potential for using chromium as an ethylene tetramerization active center because of its high catalytic activity and high selectivity to 1-octene. Here, we describe a new trinuclear PNP ligand that displays higher activity and a long lifetime for ethylene tetramerization to 1-octene.

show abstract

Section: The Effect Of Al/cr Molar Ratios On Catalytic Propertiessupporting

confidence: 73%

mentioning

confidence: 99%

Ethylene tetramerization with a highly active and long-lifetime trinuclear diphenylphosphinoamine/Cr(III)/MAO catalyst

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…Upon activation with MAO (methylaluminoxane), these catalytic systems can trimerize ethylene to 1-hexene with unprecedented selectivity and productivity. NZN ligands (multidentate nitrogen-, oxygen-, or sulfur-bridged bis(imino) ligands [14,15], with some exceptions [16]), PNP ligands (chelating nitrogen-bridged diphosphine ligands) [17,18] and SNS ligands (chelating nitrogen-bridged disulfur ligands) [17,19] are the three different kinds of mixed-donor ligands investigated most for ethylene oligomerization.…”

Section: Synthesis and Properties Of Chromium-based Catalysts With DImentioning

confidence: 99%

“…Various aluminoxanes-activated chromium(III) complexes of tridentate PNP and SNS ligands have been prepared and tested for the trimerization of ethylene to 1-hexene [17,19,[29][30][31]. The structures of the PNP and SNS ligands are closely similar.…”

Section: Sns/pnp Ligandsmentioning

confidence: 99%

See 1 more Smart Citation

Recent Research Progress in Preparation of Ethylene Oligomers with Chromium-Based Catalytic Systems

Zhu

Wang

2011

Designed Monomers and Polymers

View full text Add to dashboard Cite

Ethylene oligomers, notably 1-hexene and 1-octene, are usually used as co-monomers in the production of linear low-density polyethylene (LLDPE). Because of the great value of 1-hexene and 1-octene, there have been many reports on the selective oligomerization of ethylene to 1-hexene and 1-octene recently. Research of ethylene oligomerization focuses mainly on the synthesis of catalysts and the mechanism of oligomerization. Much of this research concerns investigation into a catalytic system that can oligomerize ethylene to 1-hexene or 1-octene with high selectivity and activity. Different kinds of catalysts have been synthesized to catalyze the reactions, and the chromium-based homogeneous catalysts are found to be the most suitable ones. This article reviews the recent research progress in synthesis of chromium catalyst systems and study on the mechanism of ethylene oligomerization catalyzed by these catalysts.

show abstract

Chromium catalysts based on PNP(NR₂)₂ ligands for selective ethylene oligomerization

Zhang

Alam

Fan

et al. 2021

Applied Organom Chemis

Self Cite

View full text Add to dashboard Cite

High active and selective 1-3 chromium catalysts based on the corresponding Ph 2 PN(cyclopentyl)P (NR 2 ) 2 -type L 1 -L 3 ligands (L 1 : R = methyl, L 2 : R = ethyl, L 3 : R = isopropyl) have been explored for selective ethylene tri-/tetramerization. We found that the ligand substituents and the experimental conditions considerably influenced the catalytic performance of 1-3 based catalysts. Combining a higher ethylene pressure can elevate the selectivity of 1-octene (67.98%) of precatalyst 1 with high catalytic activity (9.3 Â 10 6 g/[molCr h]). Furthermore, precatalysts 2-3 efficiently offer selective ethylene trimerization and afforded 97.76% 1-hexene selectivity with 5.8 Â 10 6 g/(molCr h) catalytic activity (in case precatalyst 3). A relatively low catalyst mass, high Al/Cr molar ratio, and high ethylene pressure display excellent catalytic activity and selectivity for ethylene oligomerization.

show abstract

Synthesis of a novel triple-site diphosphinoamine (PNP) ligand and its applications in ethylene tetramerization

Cited by 21 publications

References 18 publications

Ethylene tetramerization with a highly active and long-lifetime trinuclear diphenylphosphinoamine/Cr(III)/MAO catalyst

Ethylene tetramerization with a highly active and long-lifetime trinuclear diphenylphosphinoamine/Cr(III)/MAO catalyst

Recent Research Progress in Preparation of Ethylene Oligomers with Chromium-Based Catalytic Systems

Chromium catalysts based on PNP(NR₂)₂ ligands for selective ethylene oligomerization

Contact Info

Product

Resources

About

Synthesis of a novel triple-site diphosphinoamine (PNP) ligand and its applications in ethylene tetramerization

Cited by 21 publications

References 18 publications

Ethylene tetramerization with a highly active and long-lifetime trinuclear diphenylphosphinoamine/Cr(III)/MAO catalyst

Ethylene tetramerization with a highly active and long-lifetime trinuclear diphenylphosphinoamine/Cr(III)/MAO catalyst

Recent Research Progress in Preparation of Ethylene Oligomers with Chromium-Based Catalytic Systems

Chromium catalysts based on PNP(NR2)2 ligands for selective ethylene oligomerization

Contact Info

Product

Resources

About

Chromium catalysts based on PNP(NR₂)₂ ligands for selective ethylene oligomerization