1
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Li Z, Ma Y, Liu T, Zhang Q, Solan GA, Liang T, Sun WH. Exploring fluoride effects in sterically enhanced cobalt ethylene polymerisation catalysts; a combined experimental and DFT study. RSC Adv 2022; 13:14-24. [PMID: 36545290 PMCID: PMC9761560 DOI: 10.1039/d2ra05806e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
The fluoro-substituted 2,6-bis(arylimino)pyridine dichlorocobalt complexes, [2-{CMeN(2,6-(Ph2CH)2-3,4-F2C6H)}-6-(CMeNAr)C5H3N]CoCl2 (Ar = 2,6-Me2C6H3 Co1, 2,6-Et2C6H3Co2, 2,6-iPr2C6H3Co3, 2,4,6-Me3C6H2Co4, 2,6-Et-4-MeC6H2Co5), were synthesized in good yield from the corresponding unsymmetrical N,N,N'-ligands, L1-L5. Besides characterization of Co1-Co5 by FT-IR spectroscopy, 19F NMR spectroscopy and elemental analysis, the molecular structures of Co2 and Co5 were also determined highlighting the unsymmetrical nature of the terdentate ligand and the pseudo-square pyramidal geometry about the metal center. When either MAO or MMAO were employed as activators, Co1-Co5 were able to achieve a wide range of catalytic activities for ethylene polymerisation. Co5/MAO exhibited the highest activity of the study at 60 °C (7.6 × 106 g PE mol-1 (Co) h-1) which decreased to 3.3 × 106 g PE mol-1 (Co) h-1 at 80 °C. In addition, it was found that the polymerisation activity increased as the steric hindrance imparted by the ortho groups was enhanced (for MMAO: Co3 > Co5 > Co2 > Co1 > Co4), a finding that was supported by DFT calculations. Furthermore, it was shown that particularly high molecular weight polyethylene could be generated (up to 483.8 kg mol-1) when using Co5/MMAO at 30 °C, while narrow dispersities (M w/M n range: 1.8-4.7) and high linearity (T m > 131.4 °C) were a feature of all polymers produced. By comparison of Co3 with its non-fluorinated analogue using experimental data and DFT calculations, the substitution of fluorides at the meta- and para-positions was demonstrated to boost catalytic activity and improve thermal stability.
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Affiliation(s)
- Zilong Li
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of SciencesBeijing 100190China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of SciencesBeijing 100190China,Department of Chemistry, University of LeicesterUniversity RoadLeicester LE1 7RHUK
| | - Tian Liu
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of SciencesBeijing 100190China
| | - Qiuyue Zhang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of SciencesBeijing 100190China
| | - Gregory A. Solan
- Department of Chemistry, University of LeicesterUniversity RoadLeicester LE1 7RHUK
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of SciencesBeijing 100190China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of SciencesBeijing 100190China,State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of SciencesLanzhou 730000China
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2
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Thermally Stable and Highly Efficient N,N,N-Cobalt Olefin Polymerization Catalysts Affixed with N-2,4-Bis(Dibenzosuberyl)-6-Fluorophenyl Groups. Catalysts 2022. [DOI: 10.3390/catal12121569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The cobalt(II) chloride N,N,N-pincer complexes, [2-{(2,4-(C15H13)2-6-FC6H2)N=CMe}-6-(ArN=CMe)C5H3N]CoCl2 (Ar = 2,6-Me2C6H3) (Co1), 2,6-Et2C6H3 (Co2), 2,6-i-Pr2C6H3 (Co3), 2,4,6-Me3C6H2 (Co4), 2,6-Et2-4-MeC6H2 (Co5), and [2,6-{(2,4-(C15H13)2-6-FC6H2)N=CMe}2C5H3N]CoCl2 (Co6), each containing at least one N-2,4-bis(dibenzosuberyl)-6-fluorophenyl group, were synthesized in good yield from their corresponding unsymmetrical (L1–L5) and symmetrical bis(imino)pyridines (L6). The molecular structures of Co1 and Co2 spotlighted their distorted square pyramidal geometries (τ5 value range: 0.23–0.29) and variations in steric hindrance offered by the dissimilar N-aryl groups. On activation with either MAO or MMAO, Co1–Co6 all displayed high activities for ethylene polymerization, with levels falling in the order: Co1 > Co4 > Co5 > Co2 > Co3 > Co6. Indeed, the least sterically hindered 2,6-dimethyl Co1 in combination with MAO exhibited a very high activity of 1.15 × 107 g PE mol−1 (Co) h−1 at the operating temperature of 70 °C, which dropped by only 15% at 80 °C and 43% at 90 °C. Vinyl-terminated polyethylenes of high linearity and narrow dispersity were generated by all catalysts, with the most sterically hindered, Co3 and Co6, producing the highest molecular weight polymers [Mw range: 30.26–33.90 kg mol−1 (Co3) and 42.90–43.92 kg mol−1 (Co6)]. In comparison with structurally related cobalt catalysts, it was evident that the presence of the N-2,4-bis(dibenzosuberyl)-6-fluorophenyl groups had a limited effect on catalytic activity but a marked effect on thermal stability.
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3
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2-(Arylimino)benzylidene-8-arylimino-5,6,7-trihydroquinoline Cobalt(II) Dichloride Polymerization Catalysts for Polyethylenes with Narrow Polydispersity. Catalysts 2022. [DOI: 10.3390/catal12101119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A series of 2-(arylimino)benzylidene-8-arylimino-5,6,7-trihydroquinoline cobalt(II) chlorides (Co1–Co6) containing a fused ring and a more inert phenyl group as the substituent at the imino-C atom has been synthesized using a one-pot synthesis method and fully characterized by FT-IR and elemental analysis. The molecular structures of Co2 and Co5 have been confirmed by X-ray diffraction as having a distorted square pyramidal geometry around a cobalt core with a tridentate N,N,N-chelating ligand and two chlorides. On activation with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), Co1–Co6 exhibited high activities for ethylene polymerization. The least sterically hindered Co2 showed a maximum activity of 16.51 × 106 g (PE) mol−1 (Co) h−1 at a moderate temperature 50 °C. Additionally, ortho-fluoride Co6 was able to maintain a high activity not only at 70 °C but also after 60 min at 50 °C, highlighting its excellent thermal-stability and long catalytic lifetime. The resultant polyethylene showed clearly narrower molecular weight distribution (PDI: 1.3–3.1) than those produced by structurally related cobalt counterparts, indicating the positive influence of benzhydryl substitution on the catalysis. Moreover, the molecular weight (1.7–386.6 kg mol−1) of vinyl- or n-propyl-terminated polyethylene can be finely regulated by controlling polymerization parameters.
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4
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Liu T, Liu M, Ma Y, Solan GA, Liang T, Sun WH. Cobalt catalysts bearing ortho‐(4,4'‐dichlorobenzhydryl) substituents and their use in generating narrowly dispersed polyethylene of high linearity. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Tian Liu
- Institute of Chemistry Chinese Academy of Sciences Key Laboratory for Engineering Plastics CHINA
| | - Ming Liu
- Institute of Chemistry Chinese Academy of Sciences Key Laboratory for Engineering Plastics CHINA
| | - Yanping Ma
- Institute of Chemistry Chinese Academy of Sciences Key Laboratory for Engineering Plastics CHINA
| | | | - Tongling Liang
- Institute of Chemistry Chinese Academy of Sciences Key Laboratory for Engineering Plastics CHINA
| | - Wen-Hua Sun
- The Chinese Academy of Sciences Institute of Chemistry No.2, BeiyijieZhongguancun 100190 Beijing CHINA
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5
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Malik AA, Meraz MM, Yang W, Zhang Q, Sage DD, Sun WH. Catalytic Performance of Cobalt(II) Polyethylene Catalysts with Sterically Hindered Dibenzopyranyl Substituents Studied by Experimental and MLR Methods. Molecules 2022; 27:molecules27175455. [PMID: 36080222 PMCID: PMC9458042 DOI: 10.3390/molecules27175455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/14/2022] [Accepted: 08/23/2022] [Indexed: 12/02/2022] Open
Abstract
Given the great importance of cobalt catalysts supported by benchmark bis(imino)pyridine in the (oligo)polymerization, a series of dibenzopyran-incorporated symmetrical 2,6-bis(imino) pyridyl cobalt complexes (Co1–Co5) are designed and prepared using a one-pot template approach. The structures of the resulting complexes are well characterized by a number of techniques. After activation with either methylaluminoxane (MAO) or modified MAO (MMAO), the complexes Co1–Co4 are highly active for ethylene polymerization with a maximum activity of up to 7.36 × 106 g (PE) mol−1 (Co) h−1 and produced highly linear polyethylene with narrow molecular weight distributions, while Co5 is completely inactive under the standard conditions. Particularly, complex Co3 affords polyethylene with high molecular weights of 85.02 and 79.85 kg mol−1 in the presence of MAO and MMAO, respectively. The 1H and 13C NMR spectroscopy revealed the existence of vinyl end groups in the resulting polyethylene, highlighting the predominant involvement of the β-H elimination reaction in the chain-termination process. To investigate the mechanism underlying the variation of catalytic activities as a function of substituents, multiple linear regression (MLR) analysis was performed, showing the key role of open cone angle (θ) and effective net charge (Q) on catalytic activity.
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Affiliation(s)
- Arfa Abrar Malik
- CAS Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Md Mostakim Meraz
- CAS Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenhong Yang
- CAS Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- Advanced Materials Research Center, Petrochemical Research Institute, PetroChina Company Limited, Beijing 102206, China
- Correspondence: (W.Y.); (W.-H.S.); Tel.: +86-10-6255-7955 (W.-H.S.)
| | - Qiuyue Zhang
- CAS Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Desalegn Demise Sage
- CAS Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wen-Hua Sun
- CAS Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence: (W.Y.); (W.-H.S.); Tel.: +86-10-6255-7955 (W.-H.S.)
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6
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Zubkevich SV, Tuskaev VA, Gagieva SC, Bulychev BM. Catalytic oligomerization and polymerization of ethylene with complexes of iron triad metals: influence of metal nature and new perspectives. RUSSIAN CHEMICAL REVIEWS 2022. [DOI: 10.1070/rcr5021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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7
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Zhang Q, Zuo Z, Ma Y, Liang T, Yang X, Sun WH. Fluorinated 2,6-Bis(arylimino)pyridyliron Complexes Targeting Bimodal Dispersive Polyethylene; probing chain termination pathway via a combined experimental and DFT study. Dalton Trans 2022; 51:8290-8302. [DOI: 10.1039/d2dt00868h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fluorinated 2,6-bis(arylimino)pyridyl iron (II) complexes, [2-[CMeN{2,4-{(4-FC6H4)2CH}2-6-F}]-6-(CMeNAr)C5H3N]FeCl2 (Ar = 2,6-Me2C6H3 Fe1, 2,6-Et2C6H3 Fe2, 2,6-iPr2C6H3 Fe3, 2,4,6-Me3C6H2 Fe4, and 2,6-Et2-4-MeC6H2 Fe5) and [2-[CMeN{2-{(4-FC6H4)2CH}-4-{(C6H5)CHAr’}-6-F}]-6-(CMeN(2,6-iPr2C6H3))C5H3N] FeCl2 (Ar’ = 3-(4-FC6H4)2CH}2-4-NH2-5-FC6H2 Fe6), being verified with...
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8
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Han M, Zuo Z, Ma Y, Solan GA, Hu X, Liang T, Sun WH. Bis(imino)-6,7-dihydro-5 H-quinoline-cobalt complexes as highly active catalysts for the formation of vinyl-terminated PE waxes; steps towards inhibiting deactivation pathways through targeted ligand design. RSC Adv 2021; 11:39869-39878. [PMID: 35494135 PMCID: PMC9044648 DOI: 10.1039/d1ra07279j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/08/2021] [Indexed: 02/02/2023] Open
Abstract
A set of five related bis(imino)-6,7-dihydro-5H-quinoline-cobalt(ii) complexes, [2-(ArN = CPh)-8-(NAr)-C9H8N]CoCl2 (Ar = 2,6-Me2C6H3Co1, 2,6-Et2C6H3Co2, 2,6-i-Pr2C6H3Co3, 2,4,6-Me3C6H2Co4, 2,6-Et2-4-MeC6H2Co5), have been synthesized in reasonable yield by the template reaction of cobalt(ii) chloride hexahydrate, 2-benzoyl-6,7-dihydro-5H-quinolin-8-one and the corresponding aniline. The molecular structures of Co1 and Co4 highlight both the differences in the two imino-carbon environments (phenyl-capped chain vs. cyclic) and also the steric properties exerted by the bulky Nimine-aryl groups. On pre-treatment with either modified methylaluminoxane (MMAO) or methylaluminoxane (MAO), all complexes proved productive catalysts for the polymerization of ethylene. In particular, Co1/MAO was the most active reaching a very high level of 1.62 × 107 g PE per mol (Co) per h over a 30 minute run time. Owing to the presence of the imino-phenyl substituent, Co1–Co5 were able to exhibit good thermal stability by displaying appreciable catalytic activity at temperatures between 50 and 80 °C, generating polyethylenes with narrow dispersities (Mw/Mn range: 1.66–3.28). In particular, the least sterically bulky precatalysts, Co1 and Co4 formed polyethylene waxes (Mw range: 1.94–5.69 kg per mol) with high levels of vinyl unsaturation as confirmed by high temperature 1H/13C NMR spectroscopy and by IR spectroscopy. Narrowly dispersed PE waxes with high levels of vinyl functionality are produced using the depicted cobalt polymerization catalysts.![]()
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Affiliation(s)
- Mingyang Han
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China .,CAS Research/Education Center for Excellence in Molecular Sciences, University of Chinese Academy of Sciences Beijing 100049 China
| | - Zheng Zuo
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China .,CAS Research/Education Center for Excellence in Molecular Sciences, University of Chinese Academy of Sciences Beijing 100049 China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
| | - Gregory A Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China .,Department of Chemistry, University of Leicester, University Road Leicester LE1 7RH UK
| | - Xinquan Hu
- College of Chemical Engineering, Zhejiang University of Technology Hangzhou 310014 China
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences Beijing 100190 China .,CAS Research/Education Center for Excellence in Molecular Sciences, University of Chinese Academy of Sciences Beijing 100049 China.,State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China
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9
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Han M, Oleynik II, Liu M, Ma Y, Oleynik IV, Solan GA, Liang T, Sun W. Ring size enlargement in an
ortho
‐cycloalkyl‐substituted bis(imino)pyridine‐cobalt ethylene polymerization catalyst and its impact on performance and polymer properties. Appl Organomet Chem 2021. [DOI: 10.1002/aoc.6529] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Mingyang Han
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
- CAS Research/Education Center for Excellence in Molecular Sciences University of Chinese Academy of Sciences Beijing China
| | - Ivan I. Oleynik
- Vorozhtsov Novosibirsk Institute of Organic Chemistry Novosibirsk Russia
| | - Ming Liu
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
| | - Irina V. Oleynik
- Vorozhtsov Novosibirsk Institute of Organic Chemistry Novosibirsk Russia
| | - Gregory A. Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
- Department of Chemistry, University of Leicester University Road Leicester UK
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
| | - Wen‐Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
- CAS Research/Education Center for Excellence in Molecular Sciences University of Chinese Academy of Sciences Beijing China
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou China
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10
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Han M, Oleynik II, Ma Y, Oleynik IV, Solan GA, Liang T, Sun W. α,α'‐Bis (imino)‐2,3:5,6‐bis (pentamethylene)pyridines appended with benzhydryl and cycloalkyl substituents: Probing their effectiveness as tunable
N,N,N‐
supports for cobalt ethylene polymerization catalysts. Appl Organomet Chem 2021. [DOI: 10.1002/aoc.6429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Mingyang Han
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School University of Chinese Academy of Sciences Beijing China
| | - Ivan I. Oleynik
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry Novosibirsk Russia
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
| | - Irina V. Oleynik
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry Novosibirsk Russia
| | - Gregory A. Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
- Department of Chemistry University of Leicester Leicester UK
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
| | - Wen‐Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School University of Chinese Academy of Sciences Beijing China
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou China
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11
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Zuo Z, Han M, Ma Y, Solan GA, Hu X, Liang T, Sun W. Fluorinated bis(arylimino)‐6,7‐dihydro‐5
H
‐quinoline‐cobalt polymerization catalysts: Electronic versus steric modulation in the formation of vinyl‐terminated linear PE waxes. Appl Organomet Chem 2021. [DOI: 10.1002/aoc.6500] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Zheng Zuo
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School University of Chinese Academy of Sciences Beijing China
| | - Mingyang Han
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School University of Chinese Academy of Sciences Beijing China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
| | - Gregory A. Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
- Department of Chemistry University of Leicester Leicester UK
| | - Xinquan Hu
- Department of Chemistry University of Leicester Leicester UK
- College of Chemical Engineering Zhejiang University of Technology Hangzhou China
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
| | - Wen‐Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School University of Chinese Academy of Sciences Beijing China
- State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou China
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12
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Khoshsefat M, Ma Y, Sun WH. Multinuclear late transition metal catalysts for olefin polymerization. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213788] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Liu T, Ma Y, Solan G, Liang T, Sun W. Exploring
ortho
‐(4,4′‐dimethoxybenzhydryl) substitution in iron ethylene polymerization catalysts: Co‐catalyst effects, thermal stability, and polymer molecular weight variations. Appl Organomet Chem 2021. [DOI: 10.1002/aoc.6259] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Tian Liu
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing China
- CAS Research/Education Center for Excellence in Molecular Sciences University of Chinese Academy of Sciences Beijing China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing China
| | - Gregory Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing China
- Department of Chemistry University of Leicester Leicester UK
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing China
| | - Wen‐Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing China
- CAS Research/Education Center for Excellence in Molecular Sciences University of Chinese Academy of Sciences Beijing China
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou China
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14
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Zhang R, Huang Y, Ma Y, Solan GA, Hu X, Liang T, Sun WH. Thermally resilient cobalt ethylene polymerization catalysts under the joint influence of co-catalyst, gem-dimethyl substitution and ortho-cycloalkyl ring size. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123684] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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15
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Bariashir C, Zhang R, Vignesh A, Ma Y, Liang T, Sun WH. Enhancing Ethylene Polymerization of NNN-Cobalt(II) Precatalysts Adorned with a Fluoro-substituent. ACS OMEGA 2021; 6:4448-4460. [PMID: 33623851 PMCID: PMC7893795 DOI: 10.1021/acsomega.0c05916] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/22/2021] [Indexed: 06/12/2023]
Abstract
Unsymmetrical 2-(1-(2,4-dibenzhydryl-6-fluorophenylimino)ethyl)-6-(1-alkylphenyl-imino)ethyl)pyridine compounds (Ar = 2,6-Me2C6H3 in L1; 2,6-Et2C6H3 in L2; 2,6- i Pr2C6H3 in L3; 2,4,6-Me3C6H2 in L4; 2,6-Et2-4-Me-C6H2 in L5) were prepared and characterized. The treatment of CoCl2 with the compounds L1-L5 afforded the corresponding cobalt complexes Co1-Co5 in excellent yields. The molecular structures of Co3 and Co4 were determined by single-crystal X-ray diffraction, revealing the distorted-square-pyramidal geometry with three nitrogen atoms and two chlorine atoms around the cobalt center. Compared with previous bis(imino)pyridylcobalt analogues, all of the cobalt precatalysts displayed exceptionally higher activities toward ethylene polymerization with 1.32 × 107 g (PE) mol-1 (Co) h-1 at 60 °C in the presence of a co-catalyst MAO or MMAO. These cobalt catalysts produced highly linear polyethylene (PE) waxes with vinyl end groups and low molecular weight (M w up to 8.23 kg mol-1) along with a relatively lower melting point (all-round T ms < 128 °C). The narrow dispersity of resultant polyethylenes indicated the single-site active species of the catalytic system.
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Affiliation(s)
- Chantsalnyam Bariashir
- Key
Laboratory of Engineering Plastics and Beijing National Laboratory
for Molecular Science, Institute of Chemistry,
Chinese Academy of Sciences, Beijing 100190, China
- CAS
Research/Education Center for Excellence in Molecular Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Randi Zhang
- Key
Laboratory of Engineering Plastics and Beijing National Laboratory
for Molecular Science, Institute of Chemistry,
Chinese Academy of Sciences, Beijing 100190, China
- CAS
Research/Education Center for Excellence in Molecular Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Arumugam Vignesh
- Key
Laboratory of Engineering Plastics and Beijing National Laboratory
for Molecular Science, Institute of Chemistry,
Chinese Academy of Sciences, Beijing 100190, China
| | - Yanping Ma
- Key
Laboratory of Engineering Plastics and Beijing National Laboratory
for Molecular Science, Institute of Chemistry,
Chinese Academy of Sciences, Beijing 100190, China
| | - Tongling Liang
- Key
Laboratory of Engineering Plastics and Beijing National Laboratory
for Molecular Science, Institute of Chemistry,
Chinese Academy of Sciences, Beijing 100190, China
| | - Wen-Hua Sun
- Key
Laboratory of Engineering Plastics and Beijing National Laboratory
for Molecular Science, Institute of Chemistry,
Chinese Academy of Sciences, Beijing 100190, China
- CAS
Research/Education Center for Excellence in Molecular Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
- State
Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy
of Sciences, Lanzhou 730000, China
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16
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Guo L, Zhang W, Cao F, Jiang Y, Zhang R, Ma Y, Solan GA, Sun Y, Sun WH. Remote dibenzocycloheptyl substitution on a bis(arylimino)pyridyl-iron ethylene polymerization catalyst; enhanced thermal stability and unexpected effects on polymer properties. Polym Chem 2021. [DOI: 10.1039/d1py00660f] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The title iron catalyst displays exceptionally high catalytic activity at 70 °C and high activity at 100 °C; wax-like properties are a feature of the polyethylenes as are the narrow dispersities.
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Affiliation(s)
- Liwei Guo
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing institute of Fashion Technology
- Beijing 100029
| | - Wenjuan Zhang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing institute of Fashion Technology
- Beijing 100029
| | - Furong Cao
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing institute of Fashion Technology
- Beijing 100029
| | - Youshu Jiang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing institute of Fashion Technology
- Beijing 100029
| | - Randi Zhang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Gregory A. Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Yang Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
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17
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Comparison of the Reactivity and Structures for the Neutral and Cationic Bis(imino)pyridyl Iron and Cobalt Species by DFT Calculations. Catalysts 2020. [DOI: 10.3390/catal10121396] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Density Functional Theory (DFT) method was adopted to investigate and compare the reaction mechanisms of ethylene polymerization catalyzed by neutral, cationic bis(imino)pyridyl (PDI) iron and cobalt derivatives. The electronic structure and the oxidation states of the metal center and the PDI ligand were analyzed by taking spin states, natural bond orbital (NBO) charge distribution, etc. into consideration, revealing that the reactivity is closely related to the valence electron numbers instead of the charge numbers. The neutral Co(0) had the lowest reactivity as it possessed the most electrons. During the formation of the cationic Co(+)/Fe(+), one electron was mainly lost from PDI ligand rather than the metal center while the metal center maintained +II valence state through the process. Moreover, a special unsymmetrically bidentate N^N coordination manner was found to provide the deficient metal surroundings with 14e, which may initiate the reactivity of some unsymmetrical species with rich electrons. Finally, an anion [AlMe4]− participating process was proposed to explain the presence of the experimentally observed LCo(+)B(C2H4). A special intermediate, Co(+)B(C2H4) [AlMe4]− with Co in +I and absence of Co–C σ bond, was obtained. These calculation results may provide fundamental information for further understanding and designing the ethylene polymerization catalysts.
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18
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Yuan SF, Fan Z, Yan Y, Ma Y, Han M, Liang T, Sun WH. Achieving polydispersive HDPE by N, N, N-Co precatalysts appended with N-2,4-bis(di(4-methoxyphenyl)methyl)-6-methylphenyl. RSC Adv 2020; 10:43400-43411. [PMID: 35519690 PMCID: PMC9058363 DOI: 10.1039/d0ra09333e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 11/23/2020] [Indexed: 01/15/2023] Open
Abstract
A family of unsymmetrical 2-(2,4-bis(di(4-methoxyphenyl)methyl)-6-MeC6H2N)-6-(1-(arylimino)ethyl)pyridine-cobalt dichloride complexes has been synthesized and characterized by NMR spectroscopy, FT-IR spectroscopy and elemental analysis as well as single crystal X-ray diffraction for Co2 and Co4. Activated with either MAO or MMAO, all the cobalt precatalysts displayed high activities toward ethylene polymerization and produced highly linear polyethylenes with high molecular weights as well as wide polydispersities; for example, the performance using Co1/MAO at 50 °C reached 9.17 × 106 g PE (mol of Co)−1 h−1 with the production polyethylene of molecular weight as high as Mw = 3.14 × 105 g mol−1, Tm = 134.3 °C besides its wide polydispersity of Mw/Mn of 54.6. Besides the terminal vinyl group of the resultant polyethylenes, it is rare for a late-transition metal catalyst to achieve highly linear polyethylenes with not only wide polydispersity but also high molecular weights, being similar to high-density polyethylenes produced using Phillips catalyst. Introducing a practical application of N,N,N-Co precatalysts for highly linear polyethylenes with wide polydispersity and high molecular weights, targeting HDPE using Phillips catalyst.![]()
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Affiliation(s)
- Shi-Fang Yuan
- Institute of Applied Chemistry, Shanxi University Taiyuan 030006 People's Republic of China
| | - Zhe Fan
- Institute of Applied Chemistry, Shanxi University Taiyuan 030006 People's Republic of China .,Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China +86-10-62618239 +86-10-62557955
| | - Yi Yan
- Institute of Applied Chemistry, Shanxi University Taiyuan 030006 People's Republic of China .,Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China +86-10-62618239 +86-10-62557955
| | - Yanping Ma
- Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China +86-10-62618239 +86-10-62557955
| | - Mingyang Han
- Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China +86-10-62618239 +86-10-62557955
| | - Tongling Liang
- Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China +86-10-62618239 +86-10-62557955
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China +86-10-62618239 +86-10-62557955.,State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences Lanzhou 730000 China
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19
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6-Arylimino-2-(2-(1-phenylethyl)naphthalen-1-yl)-iminopyridylmetal (Fe and Co) Complexes as Highly Active Precatalysts for Ethylene Polymerization: Influence of Metal and/or Substituents on the Active, Thermostable Performance of Their Complexes and Resultant Polyethylenes. MOLECULES (BASEL, SWITZERLAND) 2020; 25:molecules25184244. [PMID: 32947823 PMCID: PMC7570845 DOI: 10.3390/molecules25184244] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/11/2020] [Accepted: 09/14/2020] [Indexed: 12/02/2022]
Abstract
A series of 6-arylimino-2-(2-(1-phenylethyl)naphthalen-1-yl)iminopyridines and their iron(II) and cobalt(II) complexes (Fe1–Fe5, Co1–Co5) were synthesized and routinely characterized as were Co3 and Co5 complexes, studied by single crystal X-ray crystallography, which individually displayed a distorted square pyramidal or trigonal bipyramid around a cobalt center. Upon treatment with either methyluminoxane (MAO) or modified methyluminoxane (MMAO), all complexes displayed high activities regarding ethylene polymerization even at an elevated temperature, enhancing the thermostability of the active species. In general, iron precatalysts showed higher activities than their cobalt analogs; for example, 10.9 × 106 g(PE) mol−1 (Co) h−1 by Co4 and 17.0 × 106 g(PE) mol−1 (Fe) h−1 by Fe4. Bulkier substituents are favored for increasing the molecular weights of the resultant polyethylenes, such as 25.6 kg mol−1 obtained by Co3 and 297 kg mol−1 obtained by Fe3. A narrow polydispersity of polyethylenes was observed by iron precatalysts activated by MMAO, indicating a single-site active species formed.
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20
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Zada M, Vignesh A, Suo H, Ma Y, Liu H, Sun WH. NNN-type iron(II) complexes consisting sterically hindered dibenzocycloheptyl group: Synthesis and catalytic activity towards ethylene polymerization. MOLECULAR CATALYSIS 2020. [DOI: 10.1016/j.mcat.2020.110981] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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21
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Zhang Q, Wu N, Xiang J, Solan GA, Suo H, Ma Y, Liang T, Sun WH. Bis-cycloheptyl-fused bis(imino)pyridine-cobalt catalysts for PE wax formation: positive effects of fluoride substitution on catalytic performance and thermal stability. Dalton Trans 2020; 49:9425-9437. [PMID: 32589179 DOI: 10.1039/d0dt01876g] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The α,α'-bis(imino)-2,3:5,6-bis(pentamethylene)pyridyl-cobalt(ii) chlorides, [2,3:5,6-{C4H8C(N(2-R1-4-R3-6-R2C6H2))}2C5HN] CoCl2 (R1 = Me, R2 = R3 = CH(p-FPh)2Co1; R1 = Et, R2 = R3 = CH(p-FPh)2Co2; R1 = i-Pr, R2 = R3 = CH(p-FPh)2Co3; R1 = Cl, R2 = R3 = CH(p-FPh)2Co4; R1 = F, R2 = R3 = CH(p-FPh)2Co5; R1 = F, R2 = R3 = CHPh2Co5'', R1 = R2 = Me, R3 = CH(p-FPh)2Co6; R1 = R3 = Me, R2 = CH(p-FPh)2Co7), have been synthesized by a one-pot template reaction of α,α'-dioxo-2,3:5,6-bis(pentamethylene)pyridine, cobalt(ii) chloride and the respective aniline in n-butanol. By contrast, the mixed cobalt(ii) chloride/acetate complex, [2,3:5,6-{C4H8C(N(2-F-4,6-(CH(p-FPh)2)2C6H2))}2C5HN]CoCl(OAc) (Co5'), was isolated when the corresponding template reaction was carried out in acetic acid. Structural characterization of Co4, Co5 and Co5'' revealed distorted square pyramidal geometries while six-coordinate Co5', incorporating a chelating acetate ligand, exhibited a distorted octahedral geometry. On activation with either MAO or MMAO, 2-fluoride-4,6-bis{di(p-fluorophenyl)methyl}-substituted Co5 showed maximum catalytic activity for ethylene polymerization at a high operating temperature of 60 °C (up to 2.1 × 107 g (PE) mol-1 (Co) h-1), producing highly linear (Tms > 121 °C), low molecular weight polyethylene waxes (Mw range: 1.5-5.0 kg mol-1) with narrow dispersity (Mw/Mn range: 1.7-2.9). End-group analysis of the waxes reveals β-H elimination as the dominant chain transfer process.
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Affiliation(s)
- Qiuyue Zhang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ningning Wu
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Junfeng Xiang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Gregory A Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, UK.
| | - Hongyi Suo
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China and State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
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22
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Han M, Zhang Q, Oleynik II, Suo H, Solan GA, Oleynik IV, Ma Y, Liang T, Sun WH. High molecular weight polyethylenes of narrow dispersity promoted using bis(arylimino)cyclohepta[b]pyridine-cobalt catalysts ortho-substituted with benzhydryl & cycloalkyl groups. Dalton Trans 2020; 49:4774-4784. [PMID: 32211662 DOI: 10.1039/d0dt00576b] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A one-pot template strategy has been utilized to synthesize sterically enhanced bis(imino)cyclohepta[b]pyridine-cobalt(ii) chlorides, [2-{(Ar)N[double bond, length as m-dash]CMe}-9-{N(Ar)}C10H10N]CoCl2 (Ar = 2-(C5H9)-4,6-(CHPh2)2C6H2Co1, 2-(C6H11)-4,6-(CHPh2)2C6H2Co2, 2-(C8H15)-4,6-(CHPh2)2C6H2Co3, 2-(C12H23)-4,6-(CHPh2)2C6H2Co4, 2,6-(C5H9)2-4-(CHPh2)C6H2Co5). All five complexes have been characterized by a combination of FT-IR spectroscopy, elemental analysis and single crystal X-ray diffraction. The molecular structures of Co1, Co3 and Co5 highlight the substantial steric hindrance imparted by the 2-cycloalkyl-6-benzhydryl or 2,6-dicyclopentyl ortho-substitution pattern; distorted square pyramidal geometries are exhibited in each case. On activation with methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all the complexes (apart from Co4/MAO) were active ethylene polymerization catalysts (up to 3.70 × 106 g PE per mol (Co) per h for Co5/MMAO), operating effectively at temperatures between 50 °C and 60 °C, producing polyethylenes with high molecular weights (up to 589.5 kg mol-1 for Co3/MAO). Furthermore, all polymers were highly linear (Tm > 130 °C) with narrow dispersities (Mw/Mn range: 2.0-3.0). The coexistence of two chain termination pathways, β-H elimination and transfer to aluminum, has been demonstrated using 13C/1H NMR spectroscopy.
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Affiliation(s)
- Mingyang Han
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiuyue Zhang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ivan I Oleynik
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Pr. Lavrentjeva 9, Novosibirsk 630090, Russia.
| | - Hongyi Suo
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gregory A Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, UK.
| | - Irina V Oleynik
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Pr. Lavrentjeva 9, Novosibirsk 630090, Russia.
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China and State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
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23
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Wang Z, Solan GA, Ma Y, Liu Q, Liang T, Sun WH. Fusing Carbocycles of Inequivalent Ring Size to a Bis(imino)pyridine-Iron Ethylene Polymerization Catalyst: Distinctive Effects on Activity, PE Molecular Weight, and Dispersity. RESEARCH 2020; 2019:9426063. [PMID: 31922146 PMCID: PMC6946285 DOI: 10.34133/2019/9426063] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 08/05/2019] [Indexed: 11/11/2022]
Abstract
The 4,6-bis(arylimino)-1,2,3,7,8,9,10-heptahydrocyclohepta[b]quinoline-iron(II) chlorides (aryl = 2,6-Me2C6H3Fe1; 2,6-Et2C6H3Fe2; 2,6-i-Pr2C6H3Fe3; 2,4,6-Me3C6H2Fe4; and 2,6-Et2-4-Me2C6H2Fe5) have been prepared in good yield by a straightforward one-pot reaction of 2,3,7,8,9,10-hexahydro-1H-cyclohepta[b]quinoline-4,6-dione, FeCl2·4H2O, and the appropriate aniline in acetic acid. All ferrous complexes have been characterized by elemental analysis and FT-IR spectroscopy. In addition, the structure of Fe3 has been determined by single crystal X-ray diffraction, which showed the iron center to adopt a distorted square pyramidal geometry with the saturated sections of the fused six- and seven-membered carbocycles to be cis-configured. In combination with either MAO or MMAO, Fe1–Fe5 exhibited exceptionally high activities for ethylene polymerization (up to 15.86 × 106 g(PE) mol−1 (Fe) h−1 at 40°C (MMAO) and 9.60 × 106 g(PE) mol−1 (Fe) h−1 at 60°C (MAO)) and produced highly linear polyethylene (HLPE, Tm ≥ 128°C) with a wide range in molecular weights; in general, the MMAO-promoted polymerizations were more active. Irrespective of the cocatalyst employed, the 2,6-Me2-substituted Fe1 and Fe4 proved the most active while the more sterically hindered 2,6-i-Pr2Fe3 the least but afforded the highest molecular weight polyethylene (Mw: 65.6–72.6 kg mol−1). Multinuclear NMR spectroscopic analysis of the polymer formed using Fe4/MMAO at 40°C showed a preference for fully saturated chain ends with a broad bimodal distribution a feature of the GPC trace (Mw/Mn = 13.4). By contrast, using Fe4/MAO at 60°C a vinyl-terminated polymer of lower molecular weight (Mw = 14.2 kg mol−1) was identified that exhibited a unimodal distribution (Mw/Mn = 3.8). Moreover, the amount of aluminoxane cocatalyst employed, temperature, and run time were also found to be influential on the modality of the polymer.
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Affiliation(s)
- Zheng Wang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,CAS Research/Education Center for Excellence in Molecular Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gregory A Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,CAS Research/Education Center for Excellence in Molecular Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingbin Liu
- College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024, China
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.,CAS Research/Education Center for Excellence in Molecular Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.,State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
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24
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Zhang Q, Zhang R, Han M, Yang W, Liang T, Sun WH. 4,4'-Difluorobenzhydryl-modified bis(imino)-pyridyliron(ii) chlorides as thermally stable precatalysts for strictly linear polyethylenes with narrow dispersities. Dalton Trans 2020; 49:7384-7396. [PMID: 32427253 DOI: 10.1039/d0dt01344g] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The 4,4'-difluorobenzhydryl-modified bis(imino)pyridylferrous chlorides, [2-{CMeN(2,6-(4-FC6H4)2CH2-4-t-BuC6H2)}-6-(CMeNAr)C5H3N] FeCl2 (Ar = 2,6-Me2C6H3Fe1, 2,6-Et2C6H3Fe2, 2,6-i-Pr2C6H3Fe3, 2,4,6-Me3C6H2Fe4, 2,6-Et-4-MeC6H2Fe5 and 2,6-(4-FC6H4)2CH2-4-t-BuC6H2Fe6), were synthesized in good yields. All iron complexes were characterized by 1H/19F NMR and elemental analysis, and the molecular structures of representative complexes Fe1 and Fe6 were determined by single crystal X-ray diffraction, which revealed a slightly distorted square pyramid around the iron center. Activated with either MAO or MMAO, Fe1-Fe5 exhibited very high activities (up to 17.2 × 106 g (PE) mol-1 (Fe) h-1 for Fe1/MMAO) toward ethylene polymerization, producing highly linear polyethylenes with narrow dispersities as required by industry and value added PEs. Importantly, the Fe1/MAO maintained an activity of 9.5 × 106 g (PE) mol-1 (Fe) h-1 at 100 °C of operating temperature, making the catalytic system suitable for practical application. Simulation quantitatively revealed the mechanism of the enhanced catalytic performance from the electronic and steric point of view.
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Affiliation(s)
- Qiuyue Zhang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Randi Zhang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingyang Han
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenhong Yang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China. and CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, China and State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
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25
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Guo J, Zhang W, Oleynik II, Solan GA, Oleynik IV, Liang T, Sun WH. Probing the effect of ortho-cycloalkyl ring size on activity and thermostability in cycloheptyl-fused N,N,N-iron ethylene polymerization catalysts. Dalton Trans 2020; 49:136-146. [DOI: 10.1039/c9dt04325j] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The depicted iron(ii) precatalysts displayed exceptionally high activities for ethylene polymerization at temperatures of up 100 °C producing linear polyethylene with a wide range of molecular weights.
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Affiliation(s)
- Jingjing Guo
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing Institute of Fashion Technology
- Beijing 100029
| | - Wenjuan Zhang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing Institute of Fashion Technology
- Beijing 100029
| | - Ivan I. Oleynik
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry
- Novosibirsk 630090
- Russia
| | - Gregory A. Solan
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing Institute of Fashion Technology
- Beijing 100029
| | - Irina V. Oleynik
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry
- Novosibirsk 630090
- Russia
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
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26
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Bariashir C, Wang Z, Ma Y, Vignesh A, Hao X, Sun WH. Finely Tuned α,α′-Bis(arylimino)-2,3:5,6-bis(pentamethylene)pyridine-Based Practical Iron Precatalysts for Targeting Highly Linear and Narrow Dispersive Polyethylene Waxes with Vinyl Ends. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00562] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chantsalnyam Bariashir
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Zheng Wang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
| | - Arumugam Vignesh
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
| | - Xiang Hao
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
- CAS Research/Education Center for Excellence in Molecular Sciences and International School, University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People’s Republic of China
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27
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Zhang Q, Ma Y, Suo H, Solan GA, Liang T, Sun W. Co‐catalyst effects on the thermal stability/activity of
N,N,N
‐Co ethylene polymerization Catalysts Bearing Fluoro‐Substituted N‐2,6‐dibenzhydrylphenyl groups. Appl Organomet Chem 2019. [DOI: 10.1002/aoc.5134] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Qiuyue Zhang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular SciencesInstitute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
- CAS Research/Education Center for Excellence in Molecular Sciences and International SchoolUniversity of Chinese Academy of Sciences Beijing 100049 China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular SciencesInstitute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
| | - Hongyi Suo
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular SciencesInstitute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
- CAS Research/Education Center for Excellence in Molecular Sciences and International SchoolUniversity of Chinese Academy of Sciences Beijing 100049 China
| | - Gregory A. Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular SciencesInstitute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
- Department of Chemistry, University of LeicesterUniversity Road Leicester LE1 7RH UK
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular SciencesInstitute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
| | - Wen‐Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular SciencesInstitute of Chemistry, Chinese Academy of Sciences Beijing 100190 China
- CAS Research/Education Center for Excellence in Molecular Sciences and International SchoolUniversity of Chinese Academy of Sciences Beijing 100049 China
- State Key Laboratory for Oxo Synthesis and Selective OxidationLanzhou Institute of Chemical Physics, Chinese Academy of Sciences Lanzhou 730000 China
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28
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Zhang R, Ma Y, Han M, Solan GA, Pi Y, Sun Y, Sun W. Exceptionally high molecular weight linear polyethylene by using
N,N,N′‐
Co catalysts appended with a
N′
‐2,6‐bis{di(4‐fluorophenyl)methyl}‐4‐nitrophenyl group. Appl Organomet Chem 2019. [DOI: 10.1002/aoc.5157] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Randi Zhang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of ChemistryChinese Academy of Sciences Beijing 100190 China
- CAS Research/Education Center for Excellence in Molecular SciencesUniversity of Chinese Academy of Sciences Beijing 100049 China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of ChemistryChinese Academy of Sciences Beijing 100190 China
| | - Mingyang Han
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of ChemistryChinese Academy of Sciences Beijing 100190 China
- CAS Research/Education Center for Excellence in Molecular SciencesUniversity of Chinese Academy of Sciences Beijing 100049 China
| | - Gregory A. Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of ChemistryChinese Academy of Sciences Beijing 100190 China
- Department of Chemistry, University of LeicesterUniversity Road Leicester LE1 7RH UK
| | - Yaqing Pi
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of ChemistryChinese Academy of Sciences Beijing 100190 China
| | - Yang Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of ChemistryChinese Academy of Sciences Beijing 100190 China
| | - Wen‐Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of ChemistryChinese Academy of Sciences Beijing 100190 China
- CAS Research/Education Center for Excellence in Molecular SciencesUniversity of Chinese Academy of Sciences Beijing 100049 China
- State Key Laboratory for Oxo Synthesis and Selective OxidationLanzhou Institute of Chemical Physics, Chinese Academy of Sciences Lanzhou 730000 China
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29
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Activity and Thermal Stability of Cobalt(II)-Based Olefin Polymerization Catalysts Adorned with Sterically Hindered Dibenzocycloheptyl Groups. Molecules 2019; 24:molecules24102007. [PMID: 31130640 PMCID: PMC6572594 DOI: 10.3390/molecules24102007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 05/23/2019] [Accepted: 05/24/2019] [Indexed: 11/24/2022] Open
Abstract
Five examples of unsymmetrical 2-(2,4-bis(dibenzocycloheptyl)-6-methylphenyl- imino)ethyl)-6-(1-(arylyimino)ethyl)pyridine derivatives (aryl = 2,6-Me2C6H3 in L1; 2,6-Et2C6H3 in L2; 2,6-i-Pr2C6H3 in L3; 2,4,6-Me3C6H2 in L4 and 2,6-Et2-4-MeC6H2 in L5) were prepared and characterized. Treatment with CoCl2 offered the corresponding cobalt precatalysts Co1–Co5, which were characterized by FT-IR and NMR spectroscopy as well as elemental analysis. The molecular structures of Co3 and Co4 determined by single crystal X-ray diffraction revealed distorted square pyramidal geometries with τ5 values of 0.052–0.215. Activated with either MAO or MMAO, the precatalysts displayed high activities in ethylene polymerization, where Co1 with the least bulky substituents exhibited a peak activity of 1.00 × 107 g PE mol−1 (Co) h−1 at 60 °C. With MAO as a cocatalyst, the activity was reduced only by one order of magnitude at 90 °C, which implies thermally stable active sites. The polymerization product was highly linear polyethylene with vinyl end groups. Co3 with the most sterically hindered active sites was capable of generating polyethylene of high molecular weight, reaching 6.46 × 105 g mol−1. Furthermore, high melting point and unimodal molecular weight distribution were observed in the resulting polyethylene. It must be stressed that the thermal stability of the catalyst and the molecular weight of the obtained polyethylene attain the highest values reported for the unsymmetrical 2,6-bis(imino)pyridylcobalt (II) chloride precatalysts.
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30
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Guo J, Wang Z, Zhang W, Oleynik II, Vignesh A, Oleynik IV, Hu X, Sun Y, Sun WH. Highly Linear Polyethylenes Achieved Using Thermo-Stable and Efficient Cobalt Precatalysts Bearing Carbocyclic-Fused NNN-Pincer Ligand. Molecules 2019; 24:molecules24061176. [PMID: 30934627 PMCID: PMC6471483 DOI: 10.3390/molecules24061176] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 03/20/2019] [Accepted: 03/21/2019] [Indexed: 11/16/2022] Open
Abstract
Six examples of 2-(1-arylimino)ethyl-9-arylimino-5,6,7,8-tetrahydrocycloheptapyridine-cobalt(II) chloride complexes, [2-(1-ArN)C2H3-9-ArN-5,6,7,8-C5H8C5H3N]CoCl2, (Ar = 2-(C5H9)-6-MeC6H3Co1, 2-(C6H11)-6-MeC6H3Co2, 2-(C8H15)-6-MeC6H3Co3, 2-(C5H9)-4,6-Me2C6H2Co4, 2-(C6H11)-4,6-Me2C6H2Co5, and 2-(C8H15)-4,6-Me2C6H2Co6), were synthesized by the direct reaction of the corresponding ortho-cycloalkyl substituted carbocyclic-fused bis(arylimino)pyridines (L1–L6) and cobalt(II) chloride in ethanol with good yields. All the synthesized ligands (L1–L6) and their corresponding cobalt complexes (Co1–Co6) were fully characterized by FT-IR, 1H/13C-NMR spectroscopy and elemental analysis. The crystal structure of Co2 and Co3 revealed that the ring puckering of both the ortho-cyclohexyl/cyclooctyl substituents and the one pyridine-fused seven-membered ring; a square-based pyramidal geometry is conferred around the metal center. On treatment with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all the six complexes showed high activities (up to 4.09 × 106 g of PE mol−1 (Co) h−1) toward ethylene polymerization at temperatures between 20 °C and 70 °C with the catalytic activities correlating with the type of ortho-cycloalkyl substituent: Cyclopentyl (Co1 and Co4) > cyclohexyl (Co2 and Co5) > cyclooctyl (Co3 and Co6) for either R = H or Me and afforded strictly linear polyethylene (Tm > 130 °C). The narrow unimodal distributions of the resulting polymers are consistent with single-site active species for the precatalyst. Furthermore, compared to the previously reported cobalt analogues, the titled precatalysts exhibited good thermo-stability (up to 70 °C) and possessed longer lifetime along with a higher molecular weight of PE (Mw: 9.2~25.3 kg mol−1).
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Affiliation(s)
- Jingjing Guo
- Beijing Key Laboratory of Clothing Materials R&D and Assessment, Beijing Engineering Research Center of Textile Nanofiber, School of Materials Science and Engineering, Beijing institute of Fashion Technology, Beijing 100029, China.
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Zheng Wang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Wenjuan Zhang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment, Beijing Engineering Research Center of Textile Nanofiber, School of Materials Science and Engineering, Beijing institute of Fashion Technology, Beijing 100029, China.
| | - Ivan I Oleynik
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Pr. Lavrentjeva 9, Novosibirsk 630090, Russia.
| | - Arumugam Vignesh
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Irina V Oleynik
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Pr. Lavrentjeva 9, Novosibirsk 630090, Russia.
| | - Xinquan Hu
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
| | - Yang Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
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31
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Zhang R, Huang Y, Solan GA, Zhang W, Hu X, Hao X, Sun WH. gem-Dimethyl-substituted bis(imino)dihydroquinolines as thermally stable supports for highly active cobalt catalysts that produce linear PE waxes. Dalton Trans 2019; 48:8175-8185. [DOI: 10.1039/c9dt01345h] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Linear polyethylene waxes with vinyl content can be generated using the depicted N,N,N′-Co catalyst at an industrially relevant operating temperature of 70 °C.
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Affiliation(s)
- Randi Zhang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Yongfeng Huang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Gregory A. Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Wenjuan Zhang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing Institute of Fashion Technology
- Beijing 100029
| | - Xinquan Hu
- College of Chemical Engineering
- Zhejiang University of Technology
- Hangzhou 310014
- China
| | - Xiang Hao
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
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32
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Zhang R, Han M, Ma Y, Solan GA, Liang T, Sun WH. Steric and electronic modulation of iron catalysts as a route to remarkably high molecular weight linear polyethylenes. Dalton Trans 2019; 48:17488-17498. [DOI: 10.1039/c9dt03880a] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The depicted N,N,N-iron(ii) chloride precatalysts, upon activation with either MAO or MMAO, not only display excellent thermal stability but are also capable of generating exceptionally high molecular weight linear polyethylenes.
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Affiliation(s)
- Randi Zhang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Mingyang Han
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Gregory A. Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Tongling Liang
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
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