Living Ziegler−Natta Cyclopolymerization of Nonconjugated Dienes:  New Classes of Microphase-Separated Polyolefin Block Copolymers via a Tandem Polymerization/Cyclopolymerization Strategy

Jayaratne, Kumudini C.; Keaton, Richard J.; Henningsen, and David A.; Sita, Lawrence R.

doi:10.1021/ja002558c

Cited by 162 publications

(44 citation statements)

References 22 publications

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“…7,8 5-Ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene (VNB) satisfactorily meet these requirements. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] The half-metallocene scandium complexes reported by Hou and his colleagues showed excellent catalytic activity for ethylene/norbornene (NBE) and ethylene/dicyclopentadiene (DCPD) copolymerization, with comonomer incorporation of 44 and 45 mol%, respectively. 20 For example, when Ph 2 -C(Flu)(Cp)ZrCl 2 (Cp ¼ C 5 H 5 , Flu ¼ uorenyl) was used in ethylene/VNB copolymerization, the catalytic activity could be up to 3520 kg per mol Zr per h with VNB incorporation of 32 mol%.…”

Section: Introductionmentioning

confidence: 99%

Efficient copolymerization of ethylene with norbornene or its derivatives using half-metallocene zirconium(iv) catalysts

Yang

Wang

et al. 2016

RSC Adv.

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A series of half-metallocene zirconium complexes CpZr(thf)Cl 2 [O-2,4-t Bu-6-(P-PhR)C 6 H 2 ] (Cp ¼ C 5 H 5 , 2a:have been synthesized by reacting CpZrCl 3 with the corresponding ligands in THF. All the complexes were characterized by ( 1 H, 13 C and 31 P) NMR spectroscopy as well as elemental analysis. X-ray structural analysis for 2a and 2d revealed a sixcoordinate distorted octahedral geometry around the zirconium center in the solid state. With the activation of a suitable cocatalyst, half-metallocene zirconium complexes 2a-d were employed to catalyze ethylene polymerization and ethylene copolymerization with cycloolefins including norbornene (NBE), 5-ethylidene-2-norbornene (ENB) and 5-vinyl-2-norbornene (VNB). All the complexes exhibited high efficiency toward the copolymerizations. High comonomer incorporations up to 62% (NBE), 76%(ENB) and 40.6% (VNB), respectively, with high catalytic activities above 10 3 kg polymer per mol Zr per h were achieved using catalyst 2c. Steric hindrance and electronic effects of the complexes or the comonomers greatly influence copolymerization behavior. Thus, catalytic activity and copolymer chain structure, including comonomer incorporation and the molecular weight, can be easily tuned over a wide range by changing catalyst and reaction conditions.

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Section: Introductionmentioning

confidence: 99%

Efficient copolymerization of ethylene with norbornene or its derivatives using half-metallocene zirconium(iv) catalysts

Yang

Wang

et al. 2016

RSC Adv.

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“…12 Early transition metal complexes have been extensively used in cyclopolymerization reactions. [13][14][15][16][17][18][19][20][21][22][23][24] The polymers produced via cyclopolymerization often contain both cis-and trans-isomeric repeating units. Owing to the high oxophilicity of early transition metals, cyclopolymerization reactions of non-conjugated dienes with polar functional groups are relatively scarce.…”

Section: Introductionmentioning

confidence: 99%

Stereo-controlled synthesis of polyolefins with cycloalkane groups by using late transition metals

Takeuchi

2012

Polym J

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Pd complexes with diimine ligands promoted the controlled cyclopolymerization of 1,6-dienes and 1,6,11-trienes to afford polymers containing 1,2-trans-cyclopentane groups with well-regulated stereochemistry. The polymerization proceeded with quantitative cyclization of the monomer, even under bulk conditions or in copolymerization reactions with ethylene and aolefins. The polymerization of monomers with oligomethylene spacers yielded polymers with five-membered rings that are accurately distributed along the polymer chain. 4-Alkylcyclopentenes and alkenylcyclohexanes were also polymerized by Pddiimine complexes to afford polymers with 1,3-trans-cyclopentane groups and 1,4-trans-cyclohexane groups, respectively. Pd complexes with a C 2 symmetrical structure promoted the isospecific polymerization of 4-alkylcyclopentenes, and the resultant isotactic polymers showed liquid crystalline properties. The mechanism of the polymerization reaction has been revealed.

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“…More recently, the use of homogeneous catalysts derived from metallocenes activated with methylaluminoxane (MAO) have been described by Waymouth and coworkers 7, 13. Since these initial reports, the cyclopolymerization of 1,5‐hexadiene has been extensively studied 8, 9, 14–23. Depending on the catalyst system employed,24 PMCP with different microstructures have been reported.…”

Section: Introductionmentioning

confidence: 99%

Cyclopolymerization of Nonconjugated Dienes with a Tridentate Phenoxyamine Hafnium Complex Supported by an sp³‐C Donor: Isotactic Enchainment and Diastereoselective cis‐Ring Closure

Edson

Coates

2009

Macromol. Rapid Commun.

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Cyclopolymerization of nonconjugated dienes produces poly(methylene-1,3-cycloalkanes) and provides a pathway to a number of stereochemically complex polymers. Activation of a diastereomeric mixture of a six-membered metallacycle complex (rac-1) in the presence of 1,5-hexadiene produced poly(methylene-1,3-cyclopentane) (PMCP) with >98% cyclization of the diene monomer. The catalyst was found to cyclopolymerize 1,5-hexadiene with relatively high activity. The microstructure of the PMCP furnished by rac-1 was found to contain a high proportion of cis-cyclopentane rings (σ = 0.70-0.74) and a relatively high isotactic content (α = 0.93-0.96). These are the first cis-enriched isotactic cyclopolymers of 1,5-hexadiene. Cyclopolymerization of 1,6-heptadiene with rac-1/B(C(6) F(5) )(3) produced poly(methylene-1,3-cyclohexane) containing 97% cis-isotactic rings. This is the first report of this highly isotactic and diastereomerically-pure microstructure.

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Living Ziegler−Natta Cyclopolymerization of Nonconjugated Dienes: New Classes of Microphase-Separated Polyolefin Block Copolymers via a Tandem Polymerization/Cyclopolymerization Strategy

Cited by 162 publications

References 22 publications

Efficient copolymerization of ethylene with norbornene or its derivatives using half-metallocene zirconium(iv) catalysts

Efficient copolymerization of ethylene with norbornene or its derivatives using half-metallocene zirconium(iv) catalysts

Stereo-controlled synthesis of polyolefins with cycloalkane groups by using late transition metals

Cyclopolymerization of Nonconjugated Dienes with a Tridentate Phenoxyamine Hafnium Complex Supported by an sp³‐C Donor: Isotactic Enchainment and Diastereoselective cis‐Ring Closure

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Living Ziegler−Natta Cyclopolymerization of Nonconjugated Dienes: New Classes of Microphase-Separated Polyolefin Block Copolymers via a Tandem Polymerization/Cyclopolymerization Strategy

Cited by 162 publications

References 22 publications

Efficient copolymerization of ethylene with norbornene or its derivatives using half-metallocene zirconium(iv) catalysts

Efficient copolymerization of ethylene with norbornene or its derivatives using half-metallocene zirconium(iv) catalysts

Stereo-controlled synthesis of polyolefins with cycloalkane groups by using late transition metals

Cyclopolymerization of Nonconjugated Dienes with a Tridentate Phenoxyamine Hafnium Complex Supported by an sp3‐C Donor: Isotactic Enchainment and Diastereoselective cis‐Ring Closure

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Cyclopolymerization of Nonconjugated Dienes with a Tridentate Phenoxyamine Hafnium Complex Supported by an sp³‐C Donor: Isotactic Enchainment and Diastereoselective cis‐Ring Closure