A Methylene-bridged salicylaldiminato tridentate [ONS] binuclear titanium complex for ethylene-norbornene copolymerization

Chen, Xiong; Zeng, Yi; Lan, Zhi‐An; You, Qingliang; Li, Tingcheng; Li, Xiang‐Dan; Zhang, Daohong; Xie, Guangyong

doi:10.1080/10601325.2018.1470467

Cited by 8 publications

(2 citation statements)

References 75 publications

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“…Therefore, in recent years, epoxide ring‐opening polymerization has received new attention . To date, various metal complexes based on Zn, Zr, Co, Cr, etc., with a variety of bidentate, tridentate and tetradentate ligands have been applied as catalysts/initiators to mediate epoxide ring‐opening copolymerization (ROCOP) …”

Section: Introductionmentioning

confidence: 99%

Ring‐opening copolymerization of epoxycyclohexane and phthalic anhydride catalyzed by the asymmetric Salen‐CrCl complex

Shi

Wen

et al. 2020

Polymer International

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A new metallic chromium complex with asymmetric salen ligand and ancillary chloride group (complex 1) has been synthesized and applied as co-catalytic system with bis(triphenylphosphine)iminium chloride (PPNCl) for the polymerization of epoxycyclohexane (CHO) and phthalic anhydride (PA). The catalyst loading, polymerization temperature, reaction time and type of cocatalyst were varied in order to explore the influences on the catalytic activity of 1. It was found that 1 exhibited relatively good activity in the catalytic copolymerization of PA and CHO to form the product with more than 90% ester linkage content under mild conditions after the addition of the PPNCl co-catalyst. This was in sharp contrast to the dinuclear [ONSO]CrCl analogue, where the resulting polymer with more than 97% ether units was achieved under identical conditions. According to the kinetic data, the apparent activation energy of CHO ring-opening copolymerization was 9.0 kJ mol −1 . A reasonable polymerization mechanism was proposed based on the interaction between the single-metal two-component catalyst system and the monomer.

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Section: Introductionmentioning

confidence: 99%

Ring‐opening copolymerization of epoxycyclohexane and phthalic anhydride catalyzed by the asymmetric Salen‐CrCl complex

Shi

Wen

et al. 2020

Polymer International

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“…Recently we have successfully prepared LLDPE from ethylene in a single reactor using non-metallocene titanium complex as the copolymerization catalyst of a tandem dual-functional catalyst systems [57,58]. We have also designed and synthesized a number of non-metallocene binuclear titanium complexes which demonstrated excellent activity for ethylene (co)polymerization [59,60,61,62]. Here we used the non-metallocene binuclear titanium complexes for the first time as copolymerization catalysts of a tandem catalyst system and described the direct synthesis of LLDPE from ethylene in a single reactor though [Fe]/[Ti] tandem catalysis, which was shown in Scheme 1.…”

Section: Introductionmentioning

confidence: 99%

Methylene-Bridged Tridentate Salicylaldiminato Binuclear Titanium Complexes as Copolymerization Catalysts for the Preparation of LLDPE through [Fe]/[Ti] Tandem Catalysis

Luo

et al. 2019

Polymers

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A novel tandem catalysis system consisted of salicylaldiminato binuclear/mononuclear titanium and 2,6-bis(imino)pyridyl iron complexes was developed to catalyze ethylene in-situ copolymerization. Linear low-density polyethylene (LLDPE) with varying molecular weight and branching degree was successfully prepared with ethylene as the sole monomer feed. The polymerization conditions, including the reaction temperature, the Fi/Ti molar ratio, and the structures of bi- or mononuclear Ti complexes were found to greatly influence the catalytic performances and the properties of obtained polymers. The polymers were characterized by differential scanning calorimetry (DSC), high temperature gel permeation chromatography (GPC) and high temperature 13C NMR spectroscopy, and found to contain ethyl, butyl, as well as some longer branches. The binuclear titanium complexes demonstrated excellent catalytic activity (up to 8.95 × 106 g/molTi·h·atm) and showed a strong positive comonomer effect when combined with the bisiminopyridyl Fe complex. The branching degree can be tuned from 2.53 to 22.89/1000C by changing the reaction conditions or using different copolymerization pre-catalysts. The melting points, crystallinity and molecular weights of the products can also be modified accordingly. The binuclear complex Ti2L1 with methylthio sidearm showed higher capability for comonomer incorporation and produced polymers with higher branching degree and much higher molecular weight compared with the mononuclear analogue.

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Binuclear titanium complexes coordinated by rigid p‐phenylene linked bis‐β‐carbonylenamine: Synthesis, structure, ethylene polymerization and copolymerization with 1,5‐hexadiene

Wang

Qin

et al. 2020

Applied Organom Chemis

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Binuclear complexes for olefin polymerization have attracted great attention due to their unique catalytic properties compared with their mononuclear counterparts. Here a series of p‐phenylene‐bridgedbis‐β‐carbonylenamine ligands and their binuclear Ti complexes Ti2L1–Ti2L3 were prepared and characterized by 1H NMR, 13C NMR, Fourier transform infrared spectroscopy, and elemental analysis. The binuclear complex Ti2L3 bearing an octylthio sidearm was further investigated by single‐crystalX‐ray diffraction, which revealed that the ligand was of β‐imino enol form, with one titanium atom ligated with six other atoms, forming a deformed octahedral configuration. Furthermore, the ligand in Ti2L3 adopted a cis configuration, which was different from the trans configuration of its m‐phenylene‐bridged derivatives. These binuclear complexes (Ti2L1–Ti2L3) could catalyze ethylene polymerization and copolymerization with 1,5‐hexadiene(1,5‐HD) efficiently under modified methylaluminoxane activation. Compared with the mononuclear complex TiL5, the binuclear catalysts were thermally more stable and showed higher activity for ethylene polymerization at higher temperatures. The activity of these titanium complexes for the copolymerization of ethylene with 1,5‐HD were over 106 g/mol Ti.h.atm, almost twice as high as for homopolymerization. Compared with the mononuclear analogue TiL5 and the m‐substituted binuclear derivative Ti2L4, binuclear catalyst Ti2L2 showed higher activity and insertion rate of the comonomer. The activity of Ti2L2 was two to three times higher than that of TiL5 and Ti2L4, indicating that p‐substituted binuclear catalysts generate clear bimetallic synergistic effect for the copolymerization of ethylene and 1,5‐HD. Meanwhile, 1,5‐HD takes 1,3‐cyclopentyl form in the polymer by 1,3‐insertion. The copolymer prepared by binuclear catalysts had higher molecular weight and wider molecular weight distribution than that prepared by the mononuclear catalyst.

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A Methylene-bridged salicylaldiminato tridentate [ONS] binuclear titanium complex for ethylene-norbornene copolymerization

Cited by 8 publications

References 75 publications

Ring‐opening copolymerization of epoxycyclohexane and phthalic anhydride catalyzed by the asymmetric Salen‐CrCl complex

Ring‐opening copolymerization of epoxycyclohexane and phthalic anhydride catalyzed by the asymmetric Salen‐CrCl complex

Methylene-Bridged Tridentate Salicylaldiminato Binuclear Titanium Complexes as Copolymerization Catalysts for the Preparation of LLDPE through [Fe]/[Ti] Tandem Catalysis

Binuclear titanium complexes coordinated by rigid p‐phenylene linked bis‐β‐carbonylenamine: Synthesis, structure, ethylene polymerization and copolymerization with 1,5‐hexadiene

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