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Romano E, Barone V, Budzelaar PHM, De Rosa C, Talarico G. Revisiting Stereoselective Propene Polymerization Mechanisms: Insights through the Activation Strain Model. Chem Asian J 2024; 19:e202400155. [PMID: 38494455 DOI: 10.1002/asia.202400155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 03/08/2024] [Accepted: 03/12/2024] [Indexed: 03/19/2024]
Abstract
The stereoelectronic factors responsible for stereoselectivity in propene polymerization with several metallocene and post-metallocene transition metal catalysts have been revisited using a combined approach of DFT calculations, the Activation Strain Model, Natural Energy Decomposition Analysis and a molecular descriptor (%VBur). There are in most cases two different paths leading to the formation of stereoerrors (SE), and the classical model does not suffice to fully understand stereoregulation. Improving stereoselectivity requires raising the energies of both SE insertion transition states. Our analyses show that the degrees of deformation of the active site (catalyst+chain) and the prochiral monomer differ for these two paths, and between different catalyst classes. Based on such analyses we discuss: a) the subtle differences in SE formation between stereoselective catalysts with different ligand frameworks; b) the reason for exceptional stereoselectivity reported for a special ansa-metallocene catalyst; c) the (double) stereocontrol origin for isoselective catalysts; d) the electronic contribution for isoselective catalysts generating SE by a modification of the ligand wrapping mode during the polymerization. Although this study will not immediately suggest new catalyst structures, we believe that understanding stereoregulation in great detail will increase our chances of success.
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Affiliation(s)
- Eugenio Romano
- Scuola Superiore Meridionale, Largo San Marcellino 10, 80138, Napoli, Italy
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126, Pisa, Italy
- Dipartimento di Scienze Chimiche, Università degli Studi di, Napoli Federico II, Via Cintia, 80126, Napoli, Italy
| | | | - Peter H M Budzelaar
- Dipartimento di Scienze Chimiche, Università degli Studi di, Napoli Federico II, Via Cintia, 80126, Napoli, Italy
| | - Claudio De Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di, Napoli Federico II, Via Cintia, 80126, Napoli, Italy
| | - Giovanni Talarico
- Scuola Superiore Meridionale, Largo San Marcellino 10, 80138, Napoli, Italy
- Dipartimento di Scienze Chimiche, Università degli Studi di, Napoli Federico II, Via Cintia, 80126, Napoli, Italy
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2
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Zhao T, Wang P, Liu N, Zhao W, Yang M, Li S, Yang Z, Sun B, Huhn T. Synthesis and X-ray structure analysis of cytotoxic heptacoordinated Salan hafnium (IV) complexes stabilized with 2,6-dipicolinic acid. J Inorg Biochem 2023; 240:112094. [PMID: 36525714 DOI: 10.1016/j.jinorgbio.2022.112094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 11/13/2022] [Accepted: 12/04/2022] [Indexed: 12/13/2022]
Abstract
Four novel Salan Hf(IV) complexes stabilized by 2,6-dipicolinic acid (Dipic) were synthesized and characterized by 1H, 13C NMR and X-ray diffraction spectroscopy. These Hf(IV)bis-chelates could be obtained in good to excellent yields (88%-91%) and demonstrated rather good stability in aqueous media and on silica gel. [L2Hf(IV)Dipic4-H,Cl] containing steric bulk L2 were stable in about 10% H2O (H2O/THF (v/v)), however, [L1Hf(IV)Dipic4-H,Cl] with non-steric L1 could slowly dissociate and release nontoxic L1. [L1-2Hf(IV)Dipic4-Cl] showed excellent anti-tumoral activity in the range of cisplatin (Hela S3: IC50 = 3.5 ± 0.4 μM, Hep G2: IC50 = 11.2 ± 2.1 μM). In addition, the cellular uptake and apoptosis investigation of [L1Hf(IV)Dipic4-Cl] suggested a fast cellular uptake process against Hela S3 cells with an almost exclusive induced apoptosis cell death path.
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Affiliation(s)
- Tiankun Zhao
- College of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
| | - Peng Wang
- College of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China
| | - Nan Liu
- College of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China
| | - Wenzhuo Zhao
- College of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China
| | - Mingjun Yang
- College of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China
| | - Shanjia Li
- College of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China
| | - Zhongduo Yang
- College of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China
| | - Bolu Sun
- College of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China
| | - Thomas Huhn
- Fachbereich Chemie and Konstanz Research School Chemical Biology, Universität Konstanz, Universitätsstr. 10, D-78457 Konstanz, Germany
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3
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Cicolella A, Romano E, Barone V, De Rosa C, Talarico G. Metallocenes and Beyond for Propene Polymerization: Energy Decomposition of Density Functional Computations Unravels the Different Interplay of Stereoelectronic Effects. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Alessandra Cicolella
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
| | - Eugenio Romano
- Scuola Superiore Meridionale, Largo San Marcellino 10, 80138 Napoli, Italy
| | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - Claudio De Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
| | - Giovanni Talarico
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
- Scuola Superiore Meridionale, Largo San Marcellino 10, 80138 Napoli, Italy
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Romano E, Budzelaar PHM, De Rosa C, Talarico G. Unconventional Stereoerror Formation Mechanisms in Nonmetallocene Propene Polymerization Systems Revealed by DFT Calculations. J Phys Chem A 2022; 126:6203-6209. [PMID: 36054494 PMCID: PMC9483984 DOI: 10.1021/acs.jpca.2c04935] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
An unconventional
mechanism for the stereoerror formation in propene
polymerization catalyzed by C1-symmetric
salalen-M systems (M = Zr, Hf) is suggested by DFT calculations. While
propagation happens with the ligand in its fac-mer conformation, a change of ligand wrapping mode from fac-mer to fac-fac is the main source of the lower stereoselectivities
obtained with Zr and Hf. This is different for the Ti analogues, where
the ligand fac-mer wrapping mode
does not play a role. Activation strain analysis indicates that the
preference for a chain stationary mechanism of the Zr/Hf species is
due to the energy required to distort the reactants (ΔEStrain) rather than to their mutual interaction
(ΔEInt).
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Affiliation(s)
- Eugenio Romano
- Scuola Superiore Meridionale, Largo San Marcellino 10, 80138 Napoli, Italy
| | - Peter H M Budzelaar
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
| | - Claudio De Rosa
- Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
| | - Giovanni Talarico
- Scuola Superiore Meridionale, Largo San Marcellino 10, 80138 Napoli, Italy.,Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
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5
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Tian T, Feng C, Wang Y, Zhu X, Yuan D, Yao Y. Synthesis of N-Methyl- o-phenylenediamine-Bridged Bis(phenolato) Lanthanide Alkoxides and Their Catalytic Performance for the (Co)Polymerization of rac-Butyrolactone and l-Lactide. Inorg Chem 2022; 61:9918-9929. [PMID: 35723524 DOI: 10.1021/acs.inorgchem.2c00582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of lanthanide alkoxo complexes supported by ONNO salalen ligands were synthesized and characterized. A one-pot reaction of LH2 (L = (2-O-C6H2-tBu2-3,5)CH═N-C6H4-N(CH3)CH2(2-O-C6H2-tBu2-3,5)) with LnCp3(THF) in a 1:1 molar ratio followed by the addition of 1 equiv of ROH (R = Bn, iPr, and CF3CH2), afforded the dimeric lanthanide alkoxo complexes [LLn(μ-OCH2Ph)]2 [Ln = Lu (1), Yb (2), Sm (3), Nd (4)], [L2Yb(μ-OiPr)]2 (5), and [L2Yb(μ-OCH2CF3)]2 (6) in good isolated yields. All these lanthanide complexes were characterized by elemental analysis and FT-IR spectroscopy. In addition, complex 1 has been characterized by NMR spectroscopy. Single-crystal X-ray diffraction analysis of complexes 1, 2, 5, and 6 showed that these lanthanide alkoxo complexes are dimeric in the solid state. Complexes 1-6 showed good activity toward the homopolymerization of rac-butyrolactone (rac-BBL) to give atactic PHB, and ionic radii of central metals have profound influence on the polymerization. The polymerization behavior of l-lactide (l-LA) initiated by complex 2 was also explored. The kinetic study revealed that the polymerizations of rac-BBL and l-LA initiated by salalen lanthanide akoxide are first order for both the monomer and the initiator concentrations. Furthermore, it was found that complexes 1 and 2 showed good activity in the copolymerization of l-LA and rac-BBL, affording gradient copolymers.
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Affiliation(s)
- Tian Tian
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering & Materials Science, Dushu Lake Campus, Soochow University, Suzhou 215123, People's Republic of China
| | - Chunping Feng
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering & Materials Science, Dushu Lake Campus, Soochow University, Suzhou 215123, People's Republic of China
| | - Yaorong Wang
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering & Materials Science, Dushu Lake Campus, Soochow University, Suzhou 215123, People's Republic of China
| | - Xuehua Zhu
- School of Chemistry and Life Science, Suzhou University of Science and Technology, Suzhou 215009, People's Republic of China
| | - Dan Yuan
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering & Materials Science, Dushu Lake Campus, Soochow University, Suzhou 215123, People's Republic of China
| | - Yingming Yao
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering & Materials Science, Dushu Lake Campus, Soochow University, Suzhou 215123, People's Republic of China
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6
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Group 4 metal complexes containing the salalen ligands: Synthesis, structural characterization and studies on the ROP of cyclic esters. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2018.03.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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7
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Group 4 Metal Complexes of Phenylene-Salalen Ligands in rac
-Lactide Polymerization Giving High Molecular Weight Stereoblock Poly(lactic acid). Chemistry 2017; 23:11540-11548. [DOI: 10.1002/chem.201701007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Indexed: 01/19/2023]
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8
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Cozzolino M, Rosen T, Goldberg I, Mazzeo M, Lamberti M. Selective Synthesis of Cyclic Carbonate by Salalen-Aluminum Complexes and Mechanistic Studies. CHEMSUSCHEM 2017; 10:1217-1223. [PMID: 27901318 DOI: 10.1002/cssc.201601479] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 11/24/2016] [Indexed: 06/06/2023]
Abstract
Salalen-aluminum complexes were synthesized and used as catalysts in the reactions of CO2 with different epoxides. The reaction of cyclohexene oxide and CO2 was thoroughly investigated. In particular, the effect of the reaction conditions (nature and equivalents of the co-catalyst, CO2 pressure, and temperature) and of the ligands (substituents on the ancillary ligand, nature of the labile ligand, and nature of the nitrogen-donor atoms) on the results of this reaction was studied. The cycloaddition reaction of CO2 with terminal epoxides bearing different functional groups was realized. Moreover, NMR mechanistic studies provided information on the catalytic cycle. Interestingly, the characterization of an intermediate species in the mechanism of the reaction of cyclohexene oxide with CO2 , catalyzed by one of the salalen-aluminum complexes, was accomplished.
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Affiliation(s)
- Mariachiara Cozzolino
- Department of Chemistry and Biology "A. Zambelli", University of Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano (SA), Italy
| | - Tomer Rosen
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Israel Goldberg
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel
| | - Mina Mazzeo
- Department of Chemistry and Biology "A. Zambelli", University of Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano (SA), Italy
| | - Marina Lamberti
- Department of Physics "E. Caianiello", University of Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano (SA), Italy
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9
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Du MR, Zhang XB, Si SM, Wang L. Theoretical insights into the reaction of Cp*(Cl)Hf(diene) with isonitriles. RSC Adv 2017. [DOI: 10.1039/c7ra08981c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The reaction of Cp*(Cl)Hf(2,3-dimethylbutadiene) with isonitriles is theoretically investigated, and detailed elementary reactions and the substitution effects are examined.
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Affiliation(s)
- Ming-Ran Du
- School of Chemical Engineering
- Anhui University of Science and Technology
- Huainan
- People's Republic of China
| | - Xiang-Biao Zhang
- School of Chemical Engineering
- Anhui University of Science and Technology
- Huainan
- People's Republic of China
| | - Sheng-Meng Si
- School of Chemical Engineering
- Anhui University of Science and Technology
- Huainan
- People's Republic of China
| | - Lei Wang
- Department of Chemistry
- Huaibei Normal University
- Huaibei
- People's Republic of China
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10
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Kirk SM, Kociok-Köhn G, Jones MD. Zirconium vs Aluminum Salalen Initiators for the Production of Biopolymers. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00718] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sarah M. Kirk
- Doctoral Training
Centre in Sustainable Chemical Technologies and ‡Department of
Chemistry, University of Bath, Bath BA2 7AY, U.K
| | - Gabriele Kociok-Köhn
- Doctoral Training
Centre in Sustainable Chemical Technologies and ‡Department of
Chemistry, University of Bath, Bath BA2 7AY, U.K
| | - Matthew D. Jones
- Doctoral Training
Centre in Sustainable Chemical Technologies and ‡Department of
Chemistry, University of Bath, Bath BA2 7AY, U.K
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11
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Wang KT, Wang YX, Wang B, Li YG, Li YS. Novel zirconium complexes with constrained cyclic β-enaminoketonato ligands: improved catalytic capability toward ethylene polymerization. Dalton Trans 2016; 45:10308-18. [PMID: 27241779 DOI: 10.1039/c6dt01391k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Novel Zr(iv) and Hf(iv) complexes bearing two constrained bulky β-enaminoketonato ligands {[ArN[double bond, length as m-dash]CH-C8H3(CH2)n(R)O]2MBn2, M = Zr or Hf; n = 1, 2 or 3; R = H or C6H5; Ar = C6H5 or C6F5} were synthesized and clearly characterized. X-ray crystal structure analysis reveals that these complexes adopt a distorted octahedral geometry. Compared with non-constrained analogues, the Zr(iv) complexes with a cyclic skeleton exhibited high catalytic activities (up to 16.4 kgPE mmolZr(-1) h(-1)) toward ethylene polymerization at ambient pressure and elevated temperatures. Moreover, the catalytic properties of these complexes could be governed exquisitely by appropriate variation of the N-aryl substituents and the size of the benzocyclane. The Zr(iv) complexes bearing a non-fluorinated N-aryl group yielded oligomers, while the fluorinated analogues bearing a five-membered or six-membered cyclane group produced high molecular weight polyethylenes (33.4-306 kg mol(-1)) under similar conditions on account of the suppression effects on β-H elimination. The Zr(iv) complexes are more active toward ethylene polymerization than the Hf(iv) analogues, and the resulting polymers exhibited higher molecular weight and narrower molecular weight distribution.
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Affiliation(s)
- Kai-Ti Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China. and University of Chinese Academy of Sciences, Changchun Branch, Changchun 130022, China
| | - Yong-Xia Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
| | - Bin Wang
- Tianjin Key Lab Composite & Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China.
| | - Yan-Guo Li
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
| | - Yue-Sheng Li
- Tianjin Key Lab Composite & Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China. and University of Chinese Academy of Sciences, Changchun Branch, Changchun 130022, China
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12
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Ma Y, Lobkovsky EB, Coates GW. Titanium(IV) catalysts with ancillary imino-spiroketonato ligands: synthesis, structure and olefin polymerization. Dalton Trans 2015; 44:12265-72. [PMID: 25984908 DOI: 10.1039/c5dt01104c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New titanium(IV) complexes having two bidentate β-iminoethyl-spiro[4,5]decan-6-onato ligands with various N-aryl substituents have been synthesized. X-ray crystal structure analysis reveals that these titanium complexes all exhibit a C2-symmetric conformation with a distorted octahedral geometry, although the specific orientation of the ligands around the titanium center varies with the identity of the N-aryl moiety. Upon activation with methylaluminoxane (MAO), these complexes catalyze the polymerization of ethylene and propylene. In the case of ethylene, most complexes exhibit the characteristics of a living polymerization between 0 °C and 25 °C, producing polyethylenes with narrow molecular weight distributions and number average molecular weights up to 100,000 g/mol. Depending on the N-aryl substituents, polymerizations of propylene result in products with tacticity ranging from slightly syndiotactic to slightly isotactic.
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Affiliation(s)
- Yuguo Ma
- Baker Laboratory, Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA
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13
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Pilone A, De Maio N, Press K, Venditto V, Pappalardo D, Mazzeo M, Pellecchia C, Kol M, Lamberti M. Ring-opening homo- and co-polymerization of lactides and ε-caprolactone by salalen aluminum complexes. Dalton Trans 2015; 44:2157-65. [PMID: 25511585 DOI: 10.1039/c4dt02616k] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aluminum complexes of non-chiral-salalen ligands were investigated in the catalysis of ring-opening polymerization (ROP) of lactide and ε-caprolactone and in their copolymerization. The aluminum-salalen complexes were found to polymerize all varieties of lactide, namely: l-, d-, rac- and meso-lactide, and showed moderate productivities. rac-LA gave rise to isotactic polylactides (with Pm up to 72%), while meso-LA gave rise to heterotactic polylactides (with a Pm of 79%). An experiment was designed for distinguishing between chain-end control and enantiomorphic-site control combined with polymeryl exchange for the isotactic stereoblock microstructure observed for the PLA produced from rac-LA; it gave strong evidence for polymeryl exchange between propagating species. Finally, this class of catalysts promoted the copolymerization of ε-caprolactone and lactides. In particular, compound allowed controlled random copolymerization of ε-caprolactone and l-lactide.
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Affiliation(s)
- Alessia Pilone
- Dipartimento di Chimica e Biologia, Università di Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
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14
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Lee CS, Park JH, Hwang EY, Park GH, Go MJ, Lee J, Lee BY. Preparation of [bis(amido)-phosphine] and [amido-phosphine sulfide or oxide] hafnium and zirconium complexes for olefin polymerization. J Organomet Chem 2014. [DOI: 10.1016/j.jorganchem.2014.09.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Stopper A, Press K, Okuda J, Goldberg I, Kol M. Zirconium Complexes of Phenylene-Bridged {ONSO} Ligands: Coordination Chemistry and Stereoselective Polymerization of rac-Lactide. Inorg Chem 2014; 53:9140-50. [DOI: 10.1021/ic501164c] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Ayellet Stopper
- School of Chemistry,
Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Konstantin Press
- School of Chemistry,
Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Jun Okuda
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, D-52056 Aachen, Germany
| | - Israel Goldberg
- School of Chemistry,
Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Moshe Kol
- School of Chemistry,
Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
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16
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Shamiri A, Chakrabarti MH, Jahan S, Hussain MA, Kaminsky W, Aravind PV, Yehye WA. The Influence of Ziegler-Natta and Metallocene Catalysts on Polyolefin Structure, Properties, and Processing Ability. MATERIALS 2014; 7:5069-5108. [PMID: 28788120 PMCID: PMC5455813 DOI: 10.3390/ma7075069] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 06/16/2014] [Accepted: 06/25/2014] [Indexed: 11/16/2022]
Abstract
50 years ago, Karl Ziegler and Giulio Natta were awarded the Nobel Prize for their discovery of the catalytic polymerization of ethylene and propylene using titanium compounds and aluminum-alkyls as co-catalysts. Polyolefins have grown to become one of the biggest of all produced polymers. New metallocene/methylaluminoxane (MAO) catalysts open the possibility to synthesize polymers with highly defined microstructure, tacticity, and steroregularity, as well as long-chain branched, or blocky copolymers with excellent properties. This improvement in polymerization is possible due to the single active sites available on the metallocene catalysts in contrast to their traditional counterparts. Moreover, these catalysts, half titanocenes/MAO, zirconocenes, and other single site catalysts can control various important parameters, such as co-monomer distribution, molecular weight, molecular weight distribution, molecular architecture, stereo-specificity, degree of linearity, and branching of the polymer. However, in most cases research in this area has reduced academia as olefin polymerization has seen significant advancements in the industries. Therefore, this paper aims to further motivate interest in polyolefin research in academia by highlighting promising and open areas for the future.
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Affiliation(s)
- Ahmad Shamiri
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Mohammed H Chakrabarti
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
- Energy Futures Lab, Electrical Engineering Building, Imperial College London, South Kensington, London SW7 2AZ, UK.
| | - Shah Jahan
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Mohd Azlan Hussain
- Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Walter Kaminsky
- Institute for Technical, Macromolecular Chemistry, University of Hamburg, Bundesstr. 45, D-20146 Hamburg, Germany.
| | - Purushothaman V Aravind
- Process and Energy Department, Delft University of Technology, Leeghwaterstraat 44, 2628 CA Delft, The Netherlands.
| | - Wageeh A Yehye
- Nanotechnology and Catalysis Research Center (NANOCEN), University of Malaya, 50603 Kuala Lumpur, Malaysia.
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17
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Park JH, Jang YE, Jeon JY, Go MJ, Lee J, Kim SK, Lee SI, Lee BY. Preparation of ansa-metallocenes for production of poly(α-olefin) lubricants. Dalton Trans 2014; 43:10132-8. [PMID: 24875269 DOI: 10.1039/c4dt00997e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An ansa-zirconocene bearing methyl substituents at all positions adjacent to the bridgehead [(-C(Ph)HC(Ph)H-)(η(5)-2,5-Me2C5H2)2ZrCl2] (4) was prepared in high yields (78%) through the reductive dimerization of 1,4-dimethyl-6-phenylfulvene utilizing ZrCl2·DME generated in situ. The structure of 4 was subsequently confirmed using X-ray crystallography. 4 exhibited excellent catalytic performance with regard to 1-decene oligomerization, which was carried out with the intention of preparing lubricant base stocks. High activities (21 × 10(6) g mol(-1) Zr h(-1) activity; TON = 150 000; TOF = 42 s(-1)) were observed at temperatures as high as 120 °C and the oligomer distribution was appropriate for lubricant application. The simulated distillation (SIMDIS) data confirmed that a wide range of oligomers were formed, ranging from the dimer (2-mer) to 20-mer. A minimal amount of the dimer and oligomers larger than the 10-mer was formed (13 and 25 wt%, respectively). Alternatively, a typical unbridged complex such as (η(5)-nBuC5H4)2ZrCl2 primarily produced dimers (54 wt%), whereas the ansa-zirconocene (EBI)ZrCl2 primarily produced oligomers larger than 10-mer (62 wt%). The methyl substituents at the positions adjacent to the bridgehead in 4 played a significant role in the catalytic performance.
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Affiliation(s)
- Ji Hae Park
- Department of Molecular Science and Technology, Ajou University, Suwon 443-749, South Korea.
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18
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Pilone A, Press K, Goldberg I, Kol M, Mazzeo M, Lamberti M. Gradient Isotactic Multiblock Polylactides from Aluminum Complexes of Chiral Salalen Ligands. J Am Chem Soc 2014; 136:2940-3. [DOI: 10.1021/ja412798x] [Citation(s) in RCA: 185] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alessia Pilone
- Dipartimento
di Chimica e Biologia, Università di Salerno, via Giovanni
Paolo II, 132, 84084 Fisciano, Italy
| | - Konstantin Press
- School
of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Israel Goldberg
- School
of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Moshe Kol
- School
of Chemistry, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Mina Mazzeo
- Dipartimento
di Chimica e Biologia, Università di Salerno, via Giovanni
Paolo II, 132, 84084 Fisciano, Italy
| | - Marina Lamberti
- Dipartimento
di Chimica e Biologia, Università di Salerno, via Giovanni
Paolo II, 132, 84084 Fisciano, Italy
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19
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Li G, Zuccaccia C, Tedesco C, D'Auria I, Macchioni A, Pellecchia C. NMR spectroscopy and X-ray characterisation of cationic N-heteroaryl-pyridylamido Zr(IV) complexes: a further level of complexity for the elusive active species of pyridylamido olefin polymerisation catalysts. Chemistry 2014; 20:232-44. [PMID: 24285639 DOI: 10.1002/chem.201303021] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Indexed: 11/09/2022]
Abstract
New [(N(-),N,N(-))ZrR2] dialkyl complexes (N(-),N,N(-)=pyrrolyl-pyridyl-amido or indolyl-pyridyl-amido; R=Me or CH2Ph) have been synthesised and tested as pre-catalysts for ethene and propene polymerisation in combination with different activators, such as B(C6F5)3, [Ph3C][B(C6F5)4], [HNMe2Ph][B(C6F5)4] or solid AlMe3-depleted methylaluminoxane (DMAO). Polyethylene (M(w)>2 MDa and M(w)/M(n)= 1.3-1.6) has been produced if pre-catalysts were activated with 1000 equivalents of DMAO (based on Al) [activity >1000 kg(PE)(mol([Zr]) h mol atm)(-1)] or by using a higher pre-catalyst concentration and a mixture of [HNPhMe2][B(C6F5)4] (1 equiv) and AliBu2H (60 equiv). In the case of propene polymerisation, activity has been observed only if pre-catalysts were treated with an excess of AliBu2H prior to addition of DMAO, which led to highly isotactic polypropylene ([mmmm]>95%). Neutral pre-catalysts and ion pairs derived from their activation have been characterised in solution by using advanced 1D and 2D NMR spectroscopy experiments. The detection and rationalisation of intercationic NOEs clearly showed the formation of dimeric species in which some pyrrolyl or indolyl π-electron density of one unit is engaged in stabilising the metal centre of the other unit, which relegates the counterions in the second coordination sphere. The solid-state structure of the dimeric indolyl-pyridyl-amidomethylzirconium derivative, determined by X-ray diffraction studies, points toward a weak Zr···η(3)-indolyl interaction. It can be hypothesised that the formation of dimeric cationic species hampers monomer coordination (especially of less reactive α-olefins) and that addition of AliBu2H is crucial to split the homodimers.
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Affiliation(s)
- Gang Li
- Dipartimento di Chimica e Biologia, Università di Salerno via Giovanni Paolo II 132, 84084 Fisciano (SA) (Italy); Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, via Elce di Sotto 8, 06123 Perugia (Italy)
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20
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Long YY, Wang YX, Li BX, Li YG, Li YS. Living syndiospecific polymerization of propylene with sterically encumbered titanium complexes activated by MMAO. Polym Chem 2014. [DOI: 10.1039/c4py00813h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
On activation with MMAO, the newly designed titanium complex with bulky substituent promotes living polymerization of propylene, affording highly syndiotactic (rrrr 98.0%) polymers with high molecular weights and narrow molecular weight distributions (Mw/Mn ≤ 1.26).
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Affiliation(s)
- Ying-Yun Long
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, China
| | - Yong-Xia Wang
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, China
| | - Bai-Xiang Li
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, China
| | - Yan-Guo Li
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, China
| | - Yue-Sheng Li
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun 130022, China
- School of Material Science and Engineering
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21
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Das M, Harms K, Chattopadhyay S. Novel tandem synthesis of bis(μ-NN′-tetrazolate) bridged dinuclear nickel(ii) Schiff base complex via [3 + 2] cyclo-addition at ambient condition. Dalton Trans 2014; 43:5643-7. [DOI: 10.1039/c3dt52398e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A bis(μ-NN′-tetrazolate) bridged dinuclear nickel(ii) Schiff base complex was synthesized via [3 + 2] cycloaddition reaction of 2-cyanopyrazine and sodium azide.
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Affiliation(s)
- Mithun Das
- Department of Chemistry
- Inorganic Section
- Jadavpur University
- Kolkata - 700 032, India
| | - Klaus Harms
- Fachbereich Chemie
- Philipps-Universität Marburg
- D-35032 Marburg, Germany
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22
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Jun SH, Park JH, Lee CS, Park SY, Go MJ, Lee J, Lee BY. Preparation of Phosphine-Amido Hafnium and Zirconium Complexes for Olefin Polymerization. Organometallics 2013. [DOI: 10.1021/om400899g] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sung Hae Jun
- Department
of Molecular Science and Technology, Ajou University, Suwon 443-749, South Korea
| | - Ji Hae Park
- Department
of Molecular Science and Technology, Ajou University, Suwon 443-749, South Korea
| | - Chun Sun Lee
- Department
of Molecular Science and Technology, Ajou University, Suwon 443-749, South Korea
| | - Seong Yeon Park
- Department
of Molecular Science and Technology, Ajou University, Suwon 443-749, South Korea
| | - Min Jeong Go
- Department
of Chemistry, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, South Korea
| | - Junseong Lee
- Department
of Chemistry, Chonnam National University, 77 Yongbong-ro, Buk-gu, Gwangju 500-757, South Korea
| | - Bun Yeoul Lee
- Department
of Molecular Science and Technology, Ajou University, Suwon 443-749, South Korea
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