Ethene polymerization by binuclear nickel—ylide complexes

Kurtev, K.; Tomov, Atanas K.

doi:10.1016/0304-5102(93)e0274-k

Cited by 44 publications

(25 citation statements)

References 8 publications

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“…1c, 5,13 That is, the large majority of polymer chains were rather short, in contrast to the materials obtained in this work. We thank Lars Bolk for GPC, DSC and viscosimetry measurement.…”

contrasting

confidence: 67%

Control of molecular weight in Ni(ii)-catalyzed polymerization via the reaction medium

et al. 2008

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“…1c, 5,13 That is, the large majority of polymer chains were rather short, in contrast to the materials obtained in this work. We thank Lars Bolk for GPC, DSC and viscosimetry measurement.…”

contrasting

confidence: 67%

Control of molecular weight in Ni(ii)-catalyzed polymerization via the reaction medium

et al. 2008

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“…Solvents were dried by conventional methods and distilled immediately prior to use. CDCl 3 31 P NMR spectroscopic data are given relative to external H 3 PO 4 . The catalytic solutions were analysed with a Varian 3900 gas chromatograph equipped with a WCOT fused silica column (25 m, 0.32 mm inside diameter, 0.25 mm film thickness).…”

Section: Methodsmentioning

confidence: 99%

An Efficient Keim‐Type Catalyst Based on an Electron‐Poor P,O‐Chelate; Tuning the Selectivity of Ethylene Oligomerisation towards Short α‐Olefins

et al. 2005

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The tertiary phosphane Ph2P‐pzONa, in which the phosphorus atom is substituted by an electron‐withdrawing pyrazol‐onato unit, reacts with trans‐[NiPhCl(PPh3)2] to afford quan‐titatively trans‐P,P'‐[NiPh(Ph2P‐pzO)(PPh3)] (4), the first Keim‐type catalyst derived from an amide. In the absence of any cocatalyst, complex 4 converts ethylene in high selectivity and activity into α‐olefins. The product distribution is drastically shifted towards lower oligomers when compared to the outcome of the reaction carried out with the conventional SHOP catalyst. Thus, when operating at 1 bar, over 99 wt.‐% of the oligomers formed are C4–C16 oligomers. In ethylene‐free solvents, 4 was shown to slowly undergo reductive elimination to produce the stabilised phosphorus ylide Ph3P‐pzO (5). Both compounds (4 and 5) were characterised by single‐crystal X‐ray diffraction analyses. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

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“…Very recently, Mecking and co‐workers and Spitz and co‐workers independently reported the nickel( II )‐catalyzed polymerization of ethylene to linear material in aqueous emulsion 73, 74. Neutral nickel( II ) complexes 7 and 8 (Scheme ) based on known bidentate P$\rm{\frown}$ O ligands75–78 were found to be suited as catalyst precursors. Stable latices of low molecular weight polyethylene could be obtained with water‐soluble catalyst precursors 7 a :73, 79, 80 for example, a dispersion of polyethylene with M w =3×10 3 g mol −1 and M w / M n =2–3 was obtained with 10 3 TO h −1 under moderate reaction conditions (70 °C, 50 bar ethylene pressure).…”

Section: Polymerization Of Ethylene and 1‐olefinsmentioning

confidence: 99%

Aqueous Catalytic Polymerization of Olefins

Mecking

Held

Bauers

2002

Angew. Chem. Int. Ed.

191

120

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Catalytic conversions in aqueous environments by transition metal complexes have become a well‐established field over the past two decades. However, the vast majority of investigations have focussed on small‐molecule synthesis. This may appear somewhat surprising as water is a particularly attractive reaction medium, especially for polymerization reactions. For example, aqueous emulsion and suspension polymerization is carried out today on a large scale by noncatalytic free‐radical routes. Polymer latices can be obtained as a product, that is, stable aqueous dispersions of polymer particles in the size range of 50 to 1000 nm. Such latices possess a unique property profile. Amongst other advantages, the use of water as a dispersing medium is particularly environmentally friendly. In comparison to these free‐radical reactions, aqueous catalytic polymerizations of olefinic monomers have received less attention. However, considerable advances and an increased awareness of this field have emerged during the past few years. A variety of high molecular weight polymers ranging from amorphous or semicrystalline polyolefins to polar‐substituted hydrophilic materials have now been prepared by catalytic polymerization of olefinic monomers in water. Polymer latices based on a number of readily available monomers are accessible and catalytic activities as high as 105 turnovers per hour have already been reported. As another example, materials prepared by aqueous catalytic polymerization have been investigated as protein inhibitors. A versatile field spanning colloids, polymer, and coordination chemistry has emerged.

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Ethene polymerization by binuclear nickel—ylide complexes

Cited by 44 publications

References 8 publications

Control of molecular weight in Ni(ii)-catalyzed polymerization via the reaction medium

Control of molecular weight in Ni(ii)-catalyzed polymerization via the reaction medium

An Efficient Keim‐Type Catalyst Based on an Electron‐Poor P,O‐Chelate; Tuning the Selectivity of Ethylene Oligomerisation towards Short α‐Olefins

Aqueous Catalytic Polymerization of Olefins

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