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Gómez-Torres A, Mavragani N, Metta-Magaña A, Murugesu M, Fortier S. Molecular Capacitors: Accessible 6- and 8-Electron Redox Chemistry from Dimeric "Ti(I)" and "Ti(0)" Synthons Supported by Imidazolin-2-Iminato Ligands. Inorg Chem 2022; 61:16856-16873. [PMID: 36219252 DOI: 10.1021/acs.inorgchem.2c02881] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reduction of the diamagnetic Ti(III)/Ti(III) dimer [Cl2Ti(μ-NImDipp)]2 (1) (NImDipp = [1,3-bis(Dipp)imidazolin-2-iminato]-, Dipp = C6H3-2,6-iPr2) with 4 and 6 equiv of KC8 generates the intramolecularly arene-masked, dinuclear titanium compounds [(μ-N-η6-ImDipp)Ti]2 (2) and {[(Et2O)2K](μ-N-μ-η6:η6-ImDipp)Ti}2 (3), respectively, in modest yields. The compounds have been structurally characterized by X-ray crystallographic analysis, and inspection of the bond metrics within the η6-coordinated aryl substituent of the bridging imidazolin-2-iminato ligand shows perturbation of the aromatic system most consistent with two-electron reduction of the ring. As such, 2 and 3 can be assigned respectively as possessing metal centers in formal Ti(III)/Ti(III) and Ti(II)/Ti(II) oxidation states. Exploration of their redox chemistry reveal the ability to reduce several substrate equivalents. For instance, treatment of 2 with excess C8H8 (COT) forms the novel COT-bridged complex [(ImDippN)(η8-COT)Ti](μ-η2:η3-COT)[Ti(η4-COT)(NImDipp)] (4) that dissociates in THF solutions to give mononuclear (ImDippN)Ti(η8-COT)(THF) (5). Addition of COT to 3 yields heterometallic [(ImDippN)(η4-COT)Ti(μ-η4:η5-COT)K(THF)(μ-η6:η4-COT)Ti(NImDipp)(μ-η4:η4-COT)K(THF)2]n (6). Compounds 4 and 5 are the products of the 4-electron oxidation of 2, while 6 stands as the 8-electron oxidation product of 3. Reduction of organozides was also explored. Low temperature reaction of 2 with 4 equiv of AdN3 gives the terminal and bridged imido complex [(ImDippN)Ti(═NAd)](μ-NAd)2[Ti(NImDipp)(N3Ad)] (7) that undergoes intermolecular C-H activation of toluene at room temperature to afford the amido compound [(ImDippN)Ti(NHAd)](μ-NAd)2[Ti(C6H4Me)(NImDipp)] (8-tol). These complexes are the 6-electron oxidation products of the reaction of 2 with AdN3. Furthermore, treatment of 3 with 4 equiv of AdN3 produces the thermally stable Ti(III)/Ti(III) terminal and bridged imido [K(18-crown-6)(THF)2]{[(ImDippN)Ti(NAd)](μ-NAd)2K[Ti(NImDipp)]} (10). Altogether, these reactions firmly establish 2 and 3 as unprecedented Ti(I)/Ti(I) and Ti(0)/Ti(0) synthons with the clear capacity to effect multielectron reductions ranging from 4 to 8 electrons.
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Affiliation(s)
- Alejandra Gómez-Torres
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Niki Mavragani
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Alejandro Metta-Magaña
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas 79968, United States
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Skye Fortier
- Department of Chemistry and Biochemistry, University of Texas at El Paso, El Paso, Texas 79968, United States
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2
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Koneczny M, Erol AB, Mauduit M, Eisen MS, Tamm M. Titanium complexes with unsymmetrically substituted imidazolin-2-iminato ligands. Dalton Trans 2022; 51:11448-11456. [PMID: 35822511 DOI: 10.1039/d2dt01740g] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of the unsymmetrical N-heterocyclic carbenes 1-(2,4,6-trimethylphenyl)-3-(adamantyl)imidazolin-2-ylidene (IAdMes, 1a) and 1-(2,6-diisopropylphenyl)-3-(adamantyl)imidazolin-2-ylidene (IAdDipp, 1b) with trimethylsilyl azide furnished the 2-(trimethylsilylimino)imidazolines 2a (ImAdMesNSiMe3) and 2b (ImAdDippNSiMe3). Desilylation by stirring in methanol gave the corresponding imidazolin-2-imines 3a (ImAdMesNH) and 3b (ImAdDippNH). 2a and 2b were treated with [TiCl4(THF)2] (THF = tetrahydrofuran) and [CpTiCl3] (Cp = η5-C5H5) to form the mono- and bis(imidazolin-2-iminato) titanium(IV) complexes [(ImAdRN)TiCl3] (4, R = Mes, Dipp), [Cp(ImAdRN)TiCl2] (5, R = Mes, Dipp), and [(ImAdRN)2TiCl2] (6, R = Mes, Dipp). The crystal structures of all compounds except 2b were determined by X-ray diffraction analysis.
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Affiliation(s)
- Marvin Koneczny
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Brauschweig, Germany.
| | - Arife Büsra Erol
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Brauschweig, Germany.
| | - Marc Mauduit
- Univ Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR-UMR 6226, F-35000 Rennes, France
| | - Moris S Eisen
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, 32000 Haifa, Israel
| | - Matthias Tamm
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Brauschweig, Germany.
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Gu J, Wang X, Zhao W, Zhuang R, Zhang C, Zhang X, Cai Y, Yuan W, Luan B, Dong B, Liu H. Synthesis of Half-Titanocene Complexes Containing π,π-Stacked Aryloxide Ligands, and Their Use as Catalysts for Ethylene (Co)polymerizations. Polymers (Basel) 2022; 14:polym14071427. [PMID: 35406299 PMCID: PMC9002825 DOI: 10.3390/polym14071427] [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: 03/07/2022] [Revised: 03/22/2022] [Accepted: 03/28/2022] [Indexed: 01/27/2023] Open
Abstract
A family of half-titanocene complexes bearing π,π-stacked aryloxide ligands and their catalytic performances towards ethylene homo-/co- polymerizations were disclosed herein. All the complexes were well characterized, and the intermolecular π,π-stacking interactions could be clearly identified from single crystal X-ray analysis, in which a stronger interaction could be reflected for aryloxides bearing bigger π-systems, e.g., pyrenoxide. Due to the formation of such interactions, these complexes were able to highly catalyze the ethylene homopolymerizations and copolymerization with 1-hexene comonomer, even without any additiveson the aryloxide group, which showed striking contrast to other half-titanocene analogues, implying the positive influence of π,π-stacking interaction in enhancing the catalytic performances of the corresponding catalysts. Moreover, it was found that addition of external pyrene molecules was capable of boosting the catalytic efficiency significantly, due to the formation of a stronger π,π-stacking interaction between the complexes and pyrene molecules.
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Affiliation(s)
- Jin Gu
- Shandong Provincial Key Laboratory of Olefin Catalysis and Polymerization, Chambroad Chemical Industry Research Institute Co., Ltd., Qingdao 266042, China; (J.G.); (R.Z.); (Y.C.); (W.Y.); (B.L.)
| | - Xiaohua Wang
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, Qingdao 266042, China; (X.W.); (W.Z.); (C.Z.); (X.Z.)
| | - Wenpeng Zhao
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, Qingdao 266042, China; (X.W.); (W.Z.); (C.Z.); (X.Z.)
| | - Rui Zhuang
- Shandong Provincial Key Laboratory of Olefin Catalysis and Polymerization, Chambroad Chemical Industry Research Institute Co., Ltd., Qingdao 266042, China; (J.G.); (R.Z.); (Y.C.); (W.Y.); (B.L.)
- Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Chunyu Zhang
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, Qingdao 266042, China; (X.W.); (W.Z.); (C.Z.); (X.Z.)
- Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Xuequan Zhang
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, Qingdao 266042, China; (X.W.); (W.Z.); (C.Z.); (X.Z.)
- Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Yinghui Cai
- Shandong Provincial Key Laboratory of Olefin Catalysis and Polymerization, Chambroad Chemical Industry Research Institute Co., Ltd., Qingdao 266042, China; (J.G.); (R.Z.); (Y.C.); (W.Y.); (B.L.)
| | - Wenbo Yuan
- Shandong Provincial Key Laboratory of Olefin Catalysis and Polymerization, Chambroad Chemical Industry Research Institute Co., Ltd., Qingdao 266042, China; (J.G.); (R.Z.); (Y.C.); (W.Y.); (B.L.)
| | - Bo Luan
- Shandong Provincial Key Laboratory of Olefin Catalysis and Polymerization, Chambroad Chemical Industry Research Institute Co., Ltd., Qingdao 266042, China; (J.G.); (R.Z.); (Y.C.); (W.Y.); (B.L.)
| | - Bo Dong
- Shandong Provincial Key Laboratory of Olefin Catalysis and Polymerization, Chambroad Chemical Industry Research Institute Co., Ltd., Qingdao 266042, China; (J.G.); (R.Z.); (Y.C.); (W.Y.); (B.L.)
- Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- Correspondence: (B.D.); (H.L.)
| | - Heng Liu
- Key Laboratory of Rubber-Plastics, Ministry of Education/Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, Qingdao 266042, China; (X.W.); (W.Z.); (C.Z.); (X.Z.)
- Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- Correspondence: (B.D.); (H.L.)
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4
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Synthesis of mono- and bis- benzimidazolin-2-iminato titanium complexes and their catalytic performances in ethylene homo- and co- polymerizations. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Pan D, Fan K, Zhang S, Wu Y. Syndiospecific Polymerization of Styrene Catalyzed by Half‐titanocenes Containing Monodentate Anionic Nitrogen Ligands. CHINESE J CHEM 2021. [DOI: 10.1002/cjoc.202100324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Dan‐Dan Pan
- State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China
| | - Ke‐Xin Fan
- State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China
| | - Shu Zhang
- State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China
| | - Yi‐Xian Wu
- State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Beijing 100029 China
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6
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Kitphaitun S, Yan Q, Nomura K. Effect of para-Substituents in Ethylene Copolymerizations with 1-Decene, 1-Dodecene, and with 2-Methyl-1-Pentene Using Phenoxide Modified Half-Titanocenes-MAO Catalyst Systems. ChemistryOpen 2021; 10:867-876. [PMID: 34227256 PMCID: PMC8409091 DOI: 10.1002/open.202100047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 05/21/2021] [Indexed: 11/16/2022] Open
Abstract
Effect of para-substituents in the ethylene (E) copolymerization with 1-decene (DC), 1-dodecene (DD), and with 2-methyl-1-pentene (2M1P) using a series of Cp*TiCl2 (O-2,6-i Pr2 -4-R-C6 H2 ) [R=H (1), t Bu (2), Ph (3), CHPh2 (4), CPh3 (5), SiMe3 (6), SiEt3 (7), and newly prepared 4-t BuC6 H4 (8) and 3,5-Me2 C6 H3 (9)]-MAO catalyst systems has been studied. The activities in these copolymerization reactions were affected by the para-substituent, and the SiMe3 (6), SiEt3 (7) and 3,5-Me2 C6 H3 (9) analogues showed the higher activities at 50 °C in the E copolymerization reactions with DC (1.06-1.44×106 kg-polymer/mol-Ti⋅h), DD (1.04-1.88×106 kg-polymer/mol-Ti⋅h) than the others, whereas no significant differences were observed in the comonomer incorporations. Complexes 6 and 7 also showed the higher activities at 50 °C in the E/2M1P copolymerization, and the 2M1P incorporation was affected by the para-substituent and the polymerization temperature; complex 9 showed better 2M1P incorporation at 25 °C.
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Affiliation(s)
- Suphitchaya Kitphaitun
- Department of ChemistryTokyo Metropolitan University1-1 Minami Osawa, HachiojiTokyo192-0397Japan
| | - Qing Yan
- Department of ChemistryTokyo Metropolitan University1-1 Minami Osawa, HachiojiTokyo192-0397Japan
| | - Kotohiro Nomura
- Department of ChemistryTokyo Metropolitan University1-1 Minami Osawa, HachiojiTokyo192-0397Japan
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7
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Wu S, Wang S, Zhu M, Gao E. CRYSTALLOGRAPHIC ANALYSIS OF A SAMARIUM(III) COMPLEX WITH 1,3,5-TRIS(1-IMIDAZOLYL)BENZENE. J STRUCT CHEM+ 2020. [DOI: 10.1134/s0022476620120124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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8
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Quinolinyl Imidazolidin-2-imine Nickel Catalyzed Efficient Copolymerization of Norbornene with para-Chlorostyrene. CHINESE JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1007/s10118-020-2400-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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9
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Doddi A, Peters M, Tamm M. N-Heterocyclic Carbene Adducts of Main Group Elements and Their Use as Ligands in Transition Metal Chemistry. Chem Rev 2019; 119:6994-7112. [PMID: 30983327 DOI: 10.1021/acs.chemrev.8b00791] [Citation(s) in RCA: 302] [Impact Index Per Article: 60.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
N-Heterocyclic carbenes (NHC) are nowadays ubiquitous and indispensable in many research fields, and it is not possible to imagine modern transition metal and main group element chemistry without the plethora of available NHCs with tailor-made electronic and steric properties. While their suitability to act as strong ligands toward transition metals has led to numerous applications of NHC complexes in homogeneous catalysis, their strong σ-donating and adaptable π-accepting abilities have also contributed to an impressive vitalization of main group chemistry with the isolation and characterization of NHC adducts of almost any element. Formally, NHC coordination to Lewis acids affords a transfer of nucleophilicity from the carbene carbon atom to the attached exocyclic moiety, and low-valent and low-coordinate adducts of the p-block elements with available lone pairs and/or polarized carbon-element π-bonds are able to act themselves as Lewis basic donor ligands toward transition metals. Accordingly, the availability of a large number of novel NHC adducts has not only produced new varieties of already existing ligand classes but has also allowed establishment of numerous complexes with unusual and often unprecedented element-metal bonds. This review aims at summarizing this development comprehensively and covers the usage of N-heterocyclic carbene adducts of the p-block elements as ligands in transition metal chemistry.
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Affiliation(s)
- Adinarayana Doddi
- Technische Universität Braunschweig, Institut für Anorganische und Analytische Chemie, Hagenring 30, 38106 Braunschweig, Germany
| | - Marius Peters
- Technische Universität Braunschweig, Institut für Anorganische und Analytische Chemie, Hagenring 30, 38106 Braunschweig, Germany
| | - Matthias Tamm
- Technische Universität Braunschweig, Institut für Anorganische und Analytische Chemie, Hagenring 30, 38106 Braunschweig, Germany
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10
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Zhang ZQ, Qu JT, Zhang S, Miao QP, Wu YX. Ethylene/propylene copolymerization catalyzed by half-titanocenes containing monodentate anionic nitrogen ligands: effect of ligands on catalytic behaviour and structure of copolymers. Polym Chem 2018. [DOI: 10.1039/c7py01807j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ethylene–propylene copolymers with high molecular weight, nearly random sequence distribution and high propylene content could be synthesized by a novel T6/TIBA/MMAO catalytic system.
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Affiliation(s)
- Zhi-Qian Zhang
- State Key Laboratory of Chemical Resource Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- China
| | - Jun-Teng Qu
- State Key Laboratory of Chemical Resource Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- China
| | - Shu Zhang
- State Key Laboratory of Chemical Resource Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- China
| | - Qiu-Ping Miao
- State Key Laboratory of Chemical Resource Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- China
| | - Yi-Xian Wu
- State Key Laboratory of Chemical Resource Engineering
- Beijing University of Chemical Technology
- Beijing 100029
- China
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11
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Li Y, Yang J, Wang B, Li Y. Efficient copolymerization of ethylene with norbornene or its derivatives using half-metallocene zirconium(iv) catalysts. RSC Adv 2016. [DOI: 10.1039/c6ra11501b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Four [O,P]ZrCpCl2 were synthesized, and showed good performance on regioselective ethylene/cyclic dienes copolymerizations. Comonomer incorporations up to 76% (ENB) and 40.6% (VNB), respectively, with activities above 103 kg per molZr per h can be achieved.
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Affiliation(s)
- Yulian Li
- Tianjin Key Lab Composite & Functional Materials
- School of Materials Science and Engineering
- Tianjin University
- Tianjin 300072
- China
| | - Jixing Yang
- Tianjin Key Lab Composite & Functional Materials
- School of Materials Science and Engineering
- Tianjin University
- Tianjin 300072
- China
| | - Bin Wang
- Tianjin Key Lab Composite & Functional Materials
- School of Materials Science and Engineering
- Tianjin University
- Tianjin 300072
- China
| | - Yuesheng Li
- Tianjin Key Lab Composite & Functional Materials
- School of Materials Science and Engineering
- Tianjin University
- Tianjin 300072
- China
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12
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Nomura K, Patamma S, Matsuda H, Katao S, Tsutsumi K, Fukuda H. Synthesis of half-titanocenes containing 1,3-imidazolidin-2-iminato ligands of type, Cp*TiCl2[1,3-R2(CH2N)2CN]: highly active catalyst precursors in ethylene (co)polymerisation. RSC Adv 2015. [DOI: 10.1039/c5ra11402k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cp*TiCl2[1,3-(2,6-Me2C6H3)2(CH2N)2CN] showed remarkable catalytic activities for ethylene/1-hexene copolymerisation with efficient comonomer incorporation (ex. activity 1 750 000 kg-polymer per mol-Ti per h).
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Affiliation(s)
- Kotohiro Nomura
- Department of Chemistry
- Tokyo Metropolitan University
- Hachioji
- Japan
- Graduate School of Materials Science
| | - Srisuda Patamma
- Department of Chemistry
- Tokyo Metropolitan University
- Hachioji
- Japan
| | - Hideshi Matsuda
- Department of Chemistry
- Tokyo Metropolitan University
- Hachioji
- Japan
| | - Shohei Katao
- Graduate School of Materials Science
- Nara Institute of Science and Technology
- Ikoma
- Japan
| | - Ken Tsutsumi
- Department of Chemistry
- Tokyo Metropolitan University
- Hachioji
- Japan
| | - Hiroya Fukuda
- Graduate School of Materials Science
- Nara Institute of Science and Technology
- Ikoma
- Japan
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