Borane Activators for Late-Transition Metal Catalysts in Norbornene Polymerization

Lassahn, Paul-Gerhard; Janiak, Christoph; Oh, Jae-Seung

doi:10.1002/1521-3927(20020101)23:1<16::aid-marc16>3.0.co;2-k

Cited by 81 publications

(49 citation statements)

References 9 publications

(13 reference statements)

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“…In general, ideal linear polymers prepared by step polymerization should be polymers with M w /M n = 2, in accordance with the FlorySchulz distribution. [22,23] On the other hand, CCPIO and CCPEO showed relatively low M n and M w . Isothianaphthene and EDOT derivatives are known as high reactive compounds because of their electron-rich conjugated systems.…”

Section: Resultsmentioning

confidence: 97%

Synthesis and optical properties of poly(phenylenethiophene)s bearing conjugated side chains

Kawashima

Kawabata

Wang

et al. 2015

Designed Monomers and Polymers

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A series of π-conjugated polymers bearing conjugated side chain were prepared by Migita-Kosugi-Stille coupling polycondensation reaction. The polymers consisting of phenylene-thiophene (CCPTO), phenylene-isothianaphthene (CCPIO), and phenylene-3,4-ethylenedioxythiophene (CCPEO) conjugated backbones in the main chains showed optical absorption peaks in the same region, while fluorescence peak of CCPTO was at larger wavelengths compared with those of CCPIO and CCPEO. The polymers showed optical rotary dispersion, indicating the optically active substituents induced one-handed helicity to the polymers.

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Section: Resultsmentioning

confidence: 97%

Synthesis and optical properties of poly(phenylenethiophene)s bearing conjugated side chains

Kawashima

Kawabata

Wang

et al. 2015

Designed Monomers and Polymers

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“…In the free β-diketone ligands, methine peaks in the keto form appear in the range of 3.5-4.0 ppm. However, this complex was found to convert to pyridinium complexes during the accumulation of the 13 C NMR data overnight. Therefore, confirmation of CH 2 (resonance at around 70 ppm) cannot be done but one peak at 65.864 ppm was observed.…”

Section: Resultsmentioning

confidence: 99%

“…13 Recently, some early and late transition metal complexes with β-ketoiminate or β-diketiminate, a bidentate monoanionic ligand have been prepared and tested for the olefin polymerization.…”

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confidence: 99%

Novel and Efficient Palladium Complexes with β-Ketoiminate Ligands for the Polymerization of Norbornene

Lee

Hwang

Yoon

et al. 2009

Bulletin of the Korean Chemical Society

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A series of the noble palladium complexes containing β-ketoiminate ligands with internal bases, [Pd(η 3 -allyl)(β-ketoiminate)], [Pd(Me)(PPh3)(β-ketoiminate)] and [Pd(Me)(β-ketoiminate)], have been successfully prepared. Crystallographically determined structures showed that these complexes are distorted square planar and pendant bases of the β-ketoiminate ligands fail to coordinate to the metal in the first two classes of complexes while bases do coordinate in the 3 rd class complexes. These complexes are active towards norbornene polymerization on activation with H(OEt2)2BAr'4 (Ar' = 3,5-bistrifluoromethylphenyl) and modified methylalumioxane (MMAO). MMAO is more efficient for the activation for polymerization. Generally, the polymerization activity increases with the following order; [Pd(allyl)(β-ketoiminate)] < [Pd(Me)(PPh3)(β-ketoiminate)] < [Pd(Me)(β-ketoiminate)].

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“…[28,29] In any event, for both iron and cobalt catalysts, a PDI centred on 2 is representative of a single-centre character for the polymerisation active species; and, in an ideal case, it denotes the occurrence of a controlled chain-termination reaction during the polymerisation process. [30,31] …”

Section: Activation Processmentioning

confidence: 99%

Polymerisation of Acrylates Catalysed by Methylaluminoxane Activated Ditertiary Phosphine Complexes of Iron and Cobalt Dichlorides

Castro

Lankinen

Leskelä

et al. 2005

Macro Chemistry & Physics

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IntroductionPhosphine ligands are extensively used in late transition metal based homogeneous catalysis, as both steric and electronic properties of the ligand can be conveniently adjusted for specific applications. Especially, when multidentate phosphine ligands are considered, the bite angle (i.e. P-M-P angle) has a direct influence on the catalyst performance: constraining the complex geometry by bridging ligands usually leads to enhanced activities and selectivities compared to monodentate ligands. [1] Iron complexes bearing bidentate phosphine ligands are known to catalyse the formation of carbon-carbon bonds, since Iwamoto et al. demonstrated that the in situ combination of iron halide, ditertiary phosphine and aluminium alkyls catalysed the co-dimerisation of 1,3-butadiene and ethylene leading to the formation of 1,4-hexadiene. [2] Similar systems based on cobalt and nickel have also been reported. [3] Nevertheless, the use of phosphine based transition metal complexes as polymerisation (i.e. multiple subsequent carbon-carbon bond formation) catalyst precursors is scarcely described in the literature, if compared to the data dealing with group 4 transition metal or latetransition metal based catalysts for the polymerisation of olefins. Alkylaluminoxane or alkylaluminium activated phosphine complexes of nickel, iron or cobalt have been reported to provide the oligomerisation of ethylene, [4] and the polymerisation of styrene, [5] norbornene [6] and 1,3-butadiene. [7] In addition, (PPh 3 ) 2 FeCl 2 [8][9][10] and in situ prepared ditertiary phosphine complexes of iron(II) bromide [11] have been used for the atom transfer radical polymerisation (ATRP) of (meth)acrylate monomers and styrene.Recently, iron(II) and cobalt(II) chloride complexes bearing bis(imino)pyridyl ligands have shown their potential for the polymerisation of tert-butyl acrylate (tBA), methyl methacrylate (MMA) and other polar monomers after activation with methylaluminoxane (MAO). [12,13] The ligand structure and polymerisation conditions have a clear influence on the catalytic activity and the molar mass of the Summary: Diphosphane complexes of iron(II) are active catalysts for the polymerisation of methyl acrylate (MA) monomers in the presence of methylaluminoxane (MAO). High molar mass atactic MA polymers (M n $ 200 kg/mol) were obtained under mild conditions with relatively narrow polydispersities (PDI $ 2). Polymerisation activity and polymer molar masses are strongly dependent on the ligand frame. The polymerisation requires the coordination of MA to a vacant coordination site at the metal centre, and processes with chain-transfer to aluminium. Cobalt analogues proved to be less efficient catalysts, giving activities in the range of 50-250 kg/mol Á h instead of 200-450 kg/mol Á h for the iron complexes. MAO activated FeCl 2 and CoCl 2 salts also perform the polymerisation of MA with low activity.Ditertiary phosphine complex of iron(II) chloride as methyl acrylate polymerisation catalyst.polymer. It was also lately demonstrated that 1,...

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Borane Activators for Late-Transition Metal Catalysts in Norbornene Polymerization

Cited by 81 publications

References 9 publications

Synthesis and optical properties of poly(phenylenethiophene)s bearing conjugated side chains

Synthesis and optical properties of poly(phenylenethiophene)s bearing conjugated side chains

Novel and Efficient Palladium Complexes with β-Ketoiminate Ligands for the Polymerization of Norbornene

Polymerisation of Acrylates Catalysed by Methylaluminoxane Activated Ditertiary Phosphine Complexes of Iron and Cobalt Dichlorides

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