Phosphine-Thiophenolate Half-Titanocene Chlorides: Synthesis, Structure, and Their Application in Ethylene (Co-)Polymerization

Tang, Xiao‐Yan; Liu, Jingyu; Li, Yuesheng

doi:10.3390/catal3010261

Cited by 3 publications

(1 citation statement)

References 57 publications

(37 reference statements)

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“…These physical properties are usually controlled by the compositions and the microstructures of the monomers, resulting from the design of the catalysts [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. For instance, with the assistance of methylaluminoxane (MAO) [ 17 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ], most of the early-transition-metal metallocene derivatives catalyzed copolymerization to afford random E–N products. The ligand steric hindrance readily impedes the norbornene insertion, and thus the PE segments are usually long.…”

Section: Introductionmentioning

confidence: 99%

Kinetics, Mechanism and Theoretical Studies of Norbornene-Ethylene Alternating Copolymerization Catalyzed by Organopalladium(II) Complexes Bearing Hemilabile α-Amino–pyridine

Huang

Liu

et al. 2017

Molecules

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Cationic methylpalladium complexes bearing hemilabile bidentate α-amino–pyridines can serve as effective precursors for catalytic alternating copolymerization of norbornene (N) and ethylene (E), under mild conditions. The norbornyl palladium complexes in the formula of {[RHNCH2(o-C6H4N)]Pd(C7H10Me)(NCMe)}(BF4) (R = iPr (2a), tBu (2b), Ph (2c), 2,6-Me2C6H3 (2d), 2,6-iPr2C6H3 (2e)) were synthesized via single insertion of norbornene into the corresponding methylpalladium complexes 1a–1e, respectively. Both square planar methyl and norbornyl palladium complexes exhibit facile equilibria of geometrical isomerization, via sterically-controlled amino decoordination–recoordination of amino–pyridine. Kinetic studies of E-insertion, N-insertion of complexes 1 and 2, and the geometric isomerization reactions have been examined by means of VT-NMR, and found in excellent agreement with the results estimated by DFT calculations. The more facile N-insertion in the cis-isomers, and ready geometric isomerization, cooperatively lead to a new mechanism that accounts for the novel catalytic formation of alternating COC.

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Section: Introductionmentioning

confidence: 99%

Kinetics, Mechanism and Theoretical Studies of Norbornene-Ethylene Alternating Copolymerization Catalyzed by Organopalladium(II) Complexes Bearing Hemilabile α-Amino–pyridine

Huang

Liu

et al. 2017

Molecules

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Synthesis and characterization of phosphine-(thio)phenolate-based half-zirconocenes and their application in ethylene (co-)polymerization

et al. 2014

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A series of novel half-zirconocenes containing phosphine-(thio)phenolate chelating ligands of the type Cp'Zr(thf)Cl2[X-2-R(1)-4-R(2)-6-(PPh2)C6H2] (Cp' = C5Me5, 2a: X = O, R(1) = Ph, R(2) = H; 2b: X = O, R(1) = (t)Bu, R(2) = H; 2c: X = O, R(1) = R(2) = (t)Bu; 2d: X = O, R(1) = SiMe3, R(2) = H; 2e: X = S, R(1) = SiMe3, R(2) = H; Cp' = C5H5, 3b: X = O, R(1) = (t)Bu, R(2) = H; 3c: X = O, R(1) = R(2) = (t)Bu; 3d: X = O, R(1) = SiMe3, R(2) = H; 3e: X = S, R(1) = SiMe3, R(2) = H) have been synthesized in high yields (74-85%). These complexes were identified by (1)H, (13)C and (31)P NMR as well as elemental analyses. Structural analysis for 2a-b and 2d revealed that these complexes adopt six-coordinate, distorted octahedral geometry around the zirconium center. These novel half-zirconocenes possessed high catalytic performance for ethylene polymerization at high temperature in the presence of MMAO. The phosphine-phenolate-based Cp* complexes produced high molecular weight polymers (M(W) > 400,000), while the Cp analogues displayed much higher activities at high temperature. Complex 3c with MMAO showed a maximum ethylene polymerization activity of 17,580 kg mol(Zr)(-1) h(-1) at 75 °C. In addition, the Cp based complexes 3b-e could promote ethylene and 1-hexene copolymerization with high activities.

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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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Phosphine-Thiophenolate Half-Titanocene Chlorides: Synthesis, Structure, and Their Application in Ethylene (Co-)Polymerization

Cited by 3 publications

References 57 publications

Kinetics, Mechanism and Theoretical Studies of Norbornene-Ethylene Alternating Copolymerization Catalyzed by Organopalladium(II) Complexes Bearing Hemilabile α-Amino–pyridine

Kinetics, Mechanism and Theoretical Studies of Norbornene-Ethylene Alternating Copolymerization Catalyzed by Organopalladium(II) Complexes Bearing Hemilabile α-Amino–pyridine

Synthesis and characterization of phosphine-(thio)phenolate-based half-zirconocenes and their application in ethylene (co-)polymerization

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

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