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Tensi L, Moretti F, Amendola A, Froese RDJ, Macchioni A, Kuhlman RL, Pearson DM, Zuccaccia C. Solution Structure and Dynamics of Hf-Al and Hf-Zn Heterobimetallic Adducts Mimicking Relevant Intermediates in Chain Transfer Reactions. Inorg Chem 2024; 63:8222-8236. [PMID: 38666625 DOI: 10.1021/acs.inorgchem.4c00476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
Cationic cyclometalated hafnocenes [CpPrCpCH2CH2CH2Hf][B(C6F5)4] (4Pr) and [CpiBuCpCH2CH(Me)CH2Hf][B(C6F5)4] (4aiBu and 4biBu) were synthesized from the corresponding [(CpPr)2HfMe][B(C6F5)4] (1Pr) and [(CpiBu)2HfMe][B(C6F5)4] (1iBu) complexes via C-H activation. 4aiBu, 4biBu, and 4Pr, mimicking a propagating M-polymeryl species (M = transition metal) with or without a β-methyl branch on the metalated chains, serve to investigate whether and how the nature of the last inserted olefin molecules changes the structure, stability, and reactivity of the corresponding heterobimetallic complexes, formed in the presence of aluminum- or zinc-alkyl chain transfer agents (CTAs), which are considered relevant intermediates in coordinative chain transfer polymerization (CCTP) and chain shuttling polymerization (CSP) technologies. NMR and DFT data indicate no major structural difference between the resulting heterobridged complexes, all characterized by the presence of multiple α-agostic interactions. On the contrary, thermodynamic and kinetic investigations, concerning the reversible formation and breaking of heterobimetallic adducts, demonstrate that isomer 4aiBu, in which the β-Me is oriented away from the reactive coordination site on Hf, but not 4biBu, having the β-Me pointing in the opposite direction, is capable of reacting with CTAs. Quantification of kinetic rate constants highlights that the formation process is rate limiting and that the nature of the last inserted α-olefin unit modulates transalkylation kinetics. The reaction of 4aiBu, 4biBu, and 4Pr with diisobutylaluminum hydride (DiBAlH) allows the interception and characterization of new heterobinuclear and heterotrinuclear species, featuring both hydride and alkyl bridging moieties, which represent structural models of elusive intermediates in CCTP and CSP processes, capturing the instant when an alkyl chain has just transferred from a transition metal to a main group metal, while the two metals remain engaged in a single heterobimetallic intermediate.
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Affiliation(s)
- Leonardo Tensi
- Department of Pharmaceutical Sciences, University of Perugia and CIRCC, Via del Liceo 1, 06123 Perugia, Italy
| | - Francesca Moretti
- Department of Chemistry, Biology and Biotechnology and CIRCC, University of Perugia and CIRCC, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Alessandra Amendola
- Department of Chemistry, Biology and Biotechnology and CIRCC, University of Perugia and CIRCC, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Robert D J Froese
- Core R&D, The Dow Chemical Company, 1776 Building, Midland, Michigan 48674, United States
| | - Alceo Macchioni
- Department of Chemistry, Biology and Biotechnology and CIRCC, University of Perugia and CIRCC, Via Elce di Sotto 8, 06123 Perugia, Italy
| | - Roger L Kuhlman
- The Dow Chemical Company, 230 Abner Jackson Parkway Herbert H Dow Building #2B104, Lake Jackson, Texas 77566, United States
| | - David M Pearson
- The Dow Chemical Company, 230 Abner Jackson Parkway Herbert H Dow Building #2B104, Lake Jackson, Texas 77566, United States
| | - Cristiano Zuccaccia
- Department of Chemistry, Biology and Biotechnology and CIRCC, University of Perugia and CIRCC, Via Elce di Sotto 8, 06123 Perugia, Italy
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Samudrala K, Conley MP. A Supported Ziegler-Type Organohafnium Site Metabolizes Polypropylene. J Am Chem Soc 2023; 145. [PMID: 37921588 PMCID: PMC10655186 DOI: 10.1021/jacs.3c05940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/26/2023] [Accepted: 10/30/2023] [Indexed: 11/04/2023]
Abstract
Cp2Hf(CH3)2 reacts with silica containing strong aluminum Lewis sites to form Cp2Hf-13CH3+ paired with aluminate anions. Solid-state NMR studies show that this reaction also forms neutral organohafnium and hafnium sites lacking methyl groups. Cp2Hf-13CH3+ reacts with isotatic polypropylene (iPP, Mn = 13.3 kDa; Đ = 2.4; mmmm = 94%; ∼110 C3H6/Hf) and H2 to form oils with moderate molecular weights (Mn = 290-1200 Da) in good yields. The aliphatic oils show characteristic 13C{1H} NMR properties consistent with complete loss of diastereoselectivity and formation of regioirregular errors under 1 atm H2. These results show that a Ziegler-Natta-type active site is compatible in a common reaction used to digest waste plastic into smaller aliphatic fragments.
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Affiliation(s)
| | - Matthew P. Conley
- Department of Chemistry, University of California, Riverside, California 92521, United States
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3
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Parfenova LV, Kovyazin PV, Bikmeeva AK, Palatov ER, Ivchenko PV, Nifant’ev IE, Khalilov LM. Catalytic Properties of Zirconocene-Based Systems in 1-Hexene Oligomerization and Structure of Metal Hydride Reaction Centers. Molecules 2023; 28:molecules28062420. [PMID: 36985393 PMCID: PMC10058051 DOI: 10.3390/molecules28062420] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 03/09/2023] Open
Abstract
Despite large-scale investigations of homogeneous single-site metallocene catalysts and systems based on them, there are still unsolved problems related to the control of their activity and chemo- and stereoselectivity. A solution to these problems is required to develop efficient methods for the synthesis of practically useful products of alkene transformations, such as dimers, oligomers, and polymers. Here we studied the catalytic activity of structurally diverse zirconocenes (L2ZrCl2, L = Cp, C5Me5, Ind, L2 = Me2CCp2, Me2SiCp2, Me2C2Cp2, rac-Me2CInd2, rac-H4C2Ind2, BIPh(Ind)2, H4C2[THInd]2), and co-catalysts activating the system, namely HAlBui2, MMAO-12, and (Ph3C)[B(C6F5)4], at low activator/Zr ratios in a 1-hexene oligomerization reaction. The influence of catalyst structure and system composition on the alkene conversion, the type of products, and the reaction stereoselectivity were investigated. The composition of hydride intermediates formed in the L2ZrCl2–HAlBui2–activator system (L2 = ansa-Me2CCp2, Ind) was studied by NMR spectroscopy. Participation of the bis-zirconium hydride complex as the precursor of catalytically active sites of the alkene dimerization reaction was shown.
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Affiliation(s)
- Lyudmila V. Parfenova
- Institute of Petrochemistry and Catalysis, Ufa Federal Research Center, Russian Academy of Sciences, Prosp. Oktyabrya, 141, 450075 Ufa, Russia
- Correspondence: ; Tel.: +7-347-284-3527
| | - Pavel V. Kovyazin
- Institute of Petrochemistry and Catalysis, Ufa Federal Research Center, Russian Academy of Sciences, Prosp. Oktyabrya, 141, 450075 Ufa, Russia
| | - Almira Kh. Bikmeeva
- Institute of Petrochemistry and Catalysis, Ufa Federal Research Center, Russian Academy of Sciences, Prosp. Oktyabrya, 141, 450075 Ufa, Russia
| | - Eldar R. Palatov
- Institute of Petrochemistry and Catalysis, Ufa Federal Research Center, Russian Academy of Sciences, Prosp. Oktyabrya, 141, 450075 Ufa, Russia
| | - Pavel V. Ivchenko
- Department of Chemistry, Lomonosov Moscow State University, 1-3 Leninskiye Gory, 119991 Moscow, Russia
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky Prosp. 29, 119991 Moscow, Russia
| | - Ilya E. Nifant’ev
- Department of Chemistry, Lomonosov Moscow State University, 1-3 Leninskiye Gory, 119991 Moscow, Russia
- A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky Prosp. 29, 119991 Moscow, Russia
| | - Leonard M. Khalilov
- Institute of Petrochemistry and Catalysis, Ufa Federal Research Center, Russian Academy of Sciences, Prosp. Oktyabrya, 141, 450075 Ufa, Russia
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Ali A, Moradian JM, Naveed A, Aziz T, Muhammad N, Maouche C, Guo Y, Yaseen W, Yassen M, Haq F, Hassan M, Fan Z, Guo L. Progress toward Polymerization Reaction Monitoring with Different Dienes: How Small Amounts of Dienes Affect ansa-Zirconocenes/Borate/Triisobutylaluminium Catalyst Systems. Polymers (Basel) 2022; 14:polym14163239. [PMID: 36015497 PMCID: PMC9414859 DOI: 10.3390/polym14163239] [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: 07/27/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 11/16/2022] Open
Abstract
The objectives of this work were to address the fundamental characteristics of ansa-zirconocene catalyzed E/diene copolymerization and E/diene/1-hexene and E/diene/propylene terpolymerizations, and the quantitative relationship between diene structure and polymer chain propagation rate constant in term of quantifiable catalytic active sites. One of the most important but unknown factors in olefins ansa-zirconocene complexes is the distribution of the catalyst between sites actively participating in polymer chain formation and dormant sites. A set of ethylene/dienes copolymerizations, and ethylene/dienes/1-hexene and ethylene/dienes/1-hexene terpolymerizations catalyzed with ansa-zirconocenes/borate/triisobutylaluminium (rac-Et(Ind)2ZrCl2/[Ph3C][B(C6F5)4]/triisobutylaluminium (TIBA) were performed in toluene at 50 °C To determine the active center [C*]/[Zr] ratio variation in the copolymerization of E with different dienes and their terpolymerization with 1-hexene and propylene, each polymer propagation chain ends were quenched with 2-thiophenecarbonyl, which selectively quenches the metal–polymer bonds through acyl chloride. The ethylene, propylene, 1-hexene, and diene composition-based propagation rate constants (kpE, kpP, kp1-H, and kpdiene), thermal (melting and crystalline) properties, composition (mol% of ethylene, propylene, 1-hexene, and diene), molecular weight, and polydispersity were also studied in this work. Systematic comparisons of the proportion of catalytically [Zr]/[C*] active sites and polymerization rate constant (kp) for ansa-zirconocenes catalyzed E/diene, E/diene/1-hexene, and E/diene/propylene polymerization have not been reported before. We evaluated the addition of 1-hexene and propylene as termonomers in the copolymerization with E/diene. To make a comparison for each diene under identical conditions, we started the polymerization by introducing an 80/20 mole ratio of E/P and 0.12 mol/L of 1-hexene in the system. The catalyst behavior against different dienes, 1-hexene, and propylene is very interesting, including changes in thermal properties, cyclization of 1-hexene, and decreased incorporation of isoprene and butadiene, changes in the diffusion barriers in the system, and its effect on kp.
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Affiliation(s)
- Amjad Ali
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jamile Mohammadi Moradian
- Biofuels Institute, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Ahmad Naveed
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China
- Correspondence: (A.N.); (L.G.)
| | - Tariq Aziz
- School of Engineering Yunqi Campus, Westlake University, Hangzhou 310024, China
| | - Nadeem Muhammad
- Department of Environmental Engineering, Wuhang University of Technology, Wuhan 430223, China
| | - Chanez Maouche
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Yintian Guo
- Zhejiang Hetian Chemical Co., Ltd., Hangzhou 310023, China
| | - Waleed Yaseen
- School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Maria Yassen
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Fazal Haq
- Department of Chemistry, Gomal University, Khyber Pakhtunkhwa 29220, Pakistan
| | - Mobashar Hassan
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Zheqing Fan
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China
| | - Li Guo
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China
- Correspondence: (A.N.); (L.G.)
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Sian L, Dall’Anese A, Macchioni A, Tensi L, Busico V, Cipullo R, Goryunov GP, Uborsky D, Voskoboynikov AZ, Ehm C, Rocchigiani L, Zuccaccia C. Role of Solvent Coordination on the Structure and Dynamics of ansa-Zirconocenium Ion Pairs in Aromatic Hydrocarbons. Organometallics 2022. [DOI: 10.1021/acs.organomet.1c00653] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Leonardo Sian
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli studi di Perugia and CIRCC, Via Elce di sotto, 8, 06123 Perugia, Italy
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Anna Dall’Anese
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli studi di Perugia and CIRCC, Via Elce di sotto, 8, 06123 Perugia, Italy
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Alceo Macchioni
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli studi di Perugia and CIRCC, Via Elce di sotto, 8, 06123 Perugia, Italy
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Leonardo Tensi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli studi di Perugia and CIRCC, Via Elce di sotto, 8, 06123 Perugia, Italy
| | - Vincenzo Busico
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Roberta Cipullo
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Georgy P. Goryunov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Dmitry Uborsky
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Alexander Z. Voskoboynikov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Christian Ehm
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Luca Rocchigiani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli studi di Perugia and CIRCC, Via Elce di sotto, 8, 06123 Perugia, Italy
| | - Cristiano Zuccaccia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli studi di Perugia and CIRCC, Via Elce di sotto, 8, 06123 Perugia, Italy
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
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Kinetic and thermal study of ethylene-propylene copolymerization catalyzed by ansa-zirconocene activated with Alkylaluminium/borate: Effects of linear and branched alkylaluminium compounds as cocatalyst. JOURNAL OF POLYMER RESEARCH 2021. [DOI: 10.1007/s10965-021-02525-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Wallace MA, Wentz CM, Sita LR. Optical Purity as a Programmable Variable for Controlling Polyolefin Tacticity in Living Coordinative Chain Transfer Polymerization: Application to the Stereomodulated LCCTP of α,ω-Nonconjugated Dienes. ACS Catal 2021. [DOI: 10.1021/acscatal.1c00633] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Mark A. Wallace
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Charlotte M. Wentz
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Lawrence R. Sita
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
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Ali A, Muhammad N, Hussain S, Jamil MI, Uddin A, Aziz T, Tufail MK, Guo Y, Wei T, Rasool G, Fan Z, Guo L. Kinetic and Thermal Study of Ethylene and Propylene Homo Polymerization Catalyzed by ansa-Zirconocene Activated with Alkylaluminum/Borate: Effects of Alkylaluminum on Polymerization Kinetics and Polymer Structure. Polymers (Basel) 2021; 13:268. [PMID: 33467427 PMCID: PMC7830494 DOI: 10.3390/polym13020268] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/07/2021] [Accepted: 01/11/2021] [Indexed: 11/24/2022] Open
Abstract
The kinetics of ethylene and propylene polymerization catalyzed by homogeneous metallocene were investigated using 2-thiophenecarbonyl chloride followed by quenched-flow methods. The studied metallocene catalysts are: rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2 (Mt-I), rac-Et(Ind)2ZrCl2 (Mt-II) activated with ([Me2NPh][B(C6F5)4] (Borate-I), [Ph3C][B(C6F5)4] (Borate-II), and were co-catalyzed with different molar ratios of alkylaluminum such as triethylaluminium (TEA) and triisobutylaluminium (TIBA). The change in molecular weight, molecular weight distribution, microstructure and thermal properties of the synthesized polymer are discussed in detail. Interestingly, both Mt-I and Mt-II showed high activity in polyethylene with productivities between 3.17 × 106 g/molMt·h to 5.06 × 106 g/molMt·h, activities were very close to each other with 100% TIBA, but Mt-II/borate-II became more active when TEA was more than 50% in cocatalyst. Similarly, Polypropylene showed the highest activity of 11.07 106 g /molMt·h with Mt-I/Borate-I/TIBA. The effects of alkylaluminum on PE molecular weight were much more complicated; MWD curve changed from mono-modal in Mt-I/borate-I/TIBA to bimodal type when TIBA was replaced by different amounts of TEA. In PE, the active center fractions [C*]/[Zr] of Mt-I/borate were higher than that of Mt-II/borate and average chain propagation rate constant (k p) value slightly decreased with the increase of TEA/TIBA ratio, but the Mt-II/borate systems showed higher k p 1007 k p (L/mol·s). In PP, the Mt-I/borate presented much higher [C*]/[Zr] and k p value than the Mt-II. This work also extend to investigate the mechanistic features of zirconocenes catalyzed olefin polymerizations that addressed the largely unknown issues in zirconocenes in the distribution of the catalyst, between species involved in polymer chain growth and dormant state. In both metallocene systems, chain transfer with alkylaluminum is the dominant way of chain termination. To understand the mechanism of cocatalyst effects on PE Mw and (MWD), the unsaturated chain ends formed via β-H transfer have been investigated by 1H NMR analysis.
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Affiliation(s)
- Amjad Ali
- Research School of Polymeric Materials, School of Material Science & Engineering, Jiangsu University, Zhenjiang 202113, China; (A.A.); (S.H.); (T.W.)
| | - Nadeem Muhammad
- Department of Enviromental Engineering, Wuhan University of Technology, Wuhan 430223, China; (N.M.); (M.K.T.); (G.R.)
| | - Shahid Hussain
- Research School of Polymeric Materials, School of Material Science & Engineering, Jiangsu University, Zhenjiang 202113, China; (A.A.); (S.H.); (T.W.)
| | - Muhammad Imran Jamil
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; (M.I.J.); (A.U.); (T.A.); (Y.G.)
| | - Azim Uddin
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; (M.I.J.); (A.U.); (T.A.); (Y.G.)
| | - Tariq Aziz
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; (M.I.J.); (A.U.); (T.A.); (Y.G.)
| | - Muhammad Khurram Tufail
- Department of Enviromental Engineering, Wuhan University of Technology, Wuhan 430223, China; (N.M.); (M.K.T.); (G.R.)
| | - Yintian Guo
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; (M.I.J.); (A.U.); (T.A.); (Y.G.)
| | - Tiantian Wei
- Research School of Polymeric Materials, School of Material Science & Engineering, Jiangsu University, Zhenjiang 202113, China; (A.A.); (S.H.); (T.W.)
| | - Ghulam Rasool
- Department of Enviromental Engineering, Wuhan University of Technology, Wuhan 430223, China; (N.M.); (M.K.T.); (G.R.)
| | - Zhiqiang Fan
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; (M.I.J.); (A.U.); (T.A.); (Y.G.)
| | - Li Guo
- Research School of Polymeric Materials, School of Material Science & Engineering, Jiangsu University, Zhenjiang 202113, China; (A.A.); (S.H.); (T.W.)
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Tensi L, Froese RDJ, Kuhlman RL, Macchioni A, Zuccaccia C. Interception of Elusive Cationic Hf–Al and Hf–Zn Heterobimetallic Adducts with Mixed Alkyl Bridges Featuring Multiple Agostic Interactions. Chemistry 2020; 26:3758-3766. [DOI: 10.1002/chem.201905699] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/14/2020] [Indexed: 11/09/2022]
Affiliation(s)
- Leonardo Tensi
- Dipartimento di Chimica, Biologia e Biotecnologie and CIRCCUniversità degli Studi di Perugia Via Elce di Sotto 8 06123 Perugia Italy
| | | | | | - Alceo Macchioni
- Dipartimento di Chimica, Biologia e Biotecnologie and CIRCCUniversità degli Studi di Perugia Via Elce di Sotto 8 06123 Perugia Italy
| | - Cristiano Zuccaccia
- Dipartimento di Chimica, Biologia e Biotecnologie and CIRCCUniversità degli Studi di Perugia Via Elce di Sotto 8 06123 Perugia Italy
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10
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Sian L, Macchioni A, Zuccaccia C. Understanding the Role of Metallocenium Ion-Pair Aggregates on the Rate of Olefin Insertion into the Metal–Carbon Bond. ACS Catal 2019. [DOI: 10.1021/acscatal.9b04929] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Leonardo Sian
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia and CIRCC, Via Elce di Sotto 8, 06123 Perugia, Italy
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Alceo Macchioni
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia and CIRCC, Via Elce di Sotto 8, 06123 Perugia, Italy
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - Cristiano Zuccaccia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia and CIRCC, Via Elce di Sotto 8, 06123 Perugia, Italy
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
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11
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Desert X, Proutiere F, Welle A, Den Dauw K, Vantomme A, Miserque O, Brusson JM, Carpentier JF, Kirillov E. Zirconocene-Catalyzed Polymerization of α-Olefins: When Intrinsic Higher Activity Is Flawed by Rapid Deactivation. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00253] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xavier Desert
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35700 Rennes, France
| | - Fabien Proutiere
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35700 Rennes, France
| | - Alexandre Welle
- Total Research & Technology Feluy, Zone Industrielle Feluy C, B-7181 Seneffe, Belgium
| | - Katty Den Dauw
- Total Research & Technology Feluy, Zone Industrielle Feluy C, B-7181 Seneffe, Belgium
| | - Aurélien Vantomme
- Total Research & Technology Feluy, Zone Industrielle Feluy C, B-7181 Seneffe, Belgium
| | - Olivier Miserque
- Total Research & Technology Feluy, Zone Industrielle Feluy C, B-7181 Seneffe, Belgium
| | - Jean-Michel Brusson
- Total S.A., Direction R&D Groupe, Tour Michelet A, 24 Cours Michelet − La Défense 10, F-92069 Paris La Défense Cedex, France
| | - Jean-François Carpentier
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35700 Rennes, France
| | - Evgueni Kirillov
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes), UMR 6226, F-35700 Rennes, France
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12
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Switzer JM, Pletcher PD, Steelman DK, Kim J, Medvedev GA, Abu-Omar MM, Caruthers JM, Delgass WN. Quantitative Modeling of the Temperature Dependence of the Kinetic Parameters for Zirconium Amine Bis(Phenolate) Catalysts for 1-Hexene Polymerization. ACS Catal 2018. [DOI: 10.1021/acscatal.8b01989] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jeffrey M. Switzer
- Davidson School of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Paul D. Pletcher
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - D. Keith Steelman
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - Jungsuk Kim
- Davidson School of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Grigori A. Medvedev
- Davidson School of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Mahdi M. Abu-Omar
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, United States
| | - James M. Caruthers
- Davidson School of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - W. Nicholas Delgass
- Davidson School of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
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13
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Abstract
Quenched-flow data for propene polymerization with rac-Me2Si(2-Me-4-Ph-1-indenyl)2ZrCl2/MAO support a picture where removal of MAO qualitatively changes the kinetic profile from a mainly enthalpic to a mainly entropic barrier. DFT studies suggest that a not previously recognized singly-bridged end-on coordination mode of Me6Al2 to catalytically active centers may be kinetically relevant as a resting state. In contrast, the more traditional doubly-bridged complex of Me3Al is proposed to be more relevant to chain transfer to cocatalyst.
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Affiliation(s)
- C Ehm
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy.
| | - R Cipullo
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy.
| | - P H M Budzelaar
- Department of Chemistry, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - V Busico
- Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Via Cintia, 80126 Napoli, Italy.
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14
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Vatamanu M. Observation of zirconium allyl species formed during zirconocene-catalyzed propene polymerization and mechanistic insights. J Catal 2015. [DOI: 10.1016/j.jcat.2014.12.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Wang L, Poirier V, Ghiotto F, Bochmann M, Cannon RD, Carpentier JF, Sarazin Y. Kinetic Analysis of the Immortal Ring-Opening Polymerization of Cyclic Esters: A Case Study with Tin(II) Catalysts. Macromolecules 2014. [DOI: 10.1021/ma500124k] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Lingfang Wang
- Organometallics: Materials and Catalysis,
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Valentin Poirier
- Organometallics: Materials and Catalysis,
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Fabio Ghiotto
- Wolfson Materials and Catalysis Centre, School of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K
| | - Manfred Bochmann
- Wolfson Materials and Catalysis Centre, School of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K
| | - Roderick D. Cannon
- Wolfson Materials and Catalysis Centre, School of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K
| | - Jean-François Carpentier
- Organometallics: Materials and Catalysis,
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France
| | - Yann Sarazin
- Organometallics: Materials and Catalysis,
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes Cedex, France
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16
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Sharma M, Yameen HS, Tumanskii B, Filimon SA, Tamm M, Eisen MS. Bis(1,3-di-tert-butylimidazolin-2-iminato) Titanium Complexes as Effective Catalysts for the Monodisperse Polymerization of Propylene. J Am Chem Soc 2012; 134:17234-44. [DOI: 10.1021/ja3071545] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Manab Sharma
- Schulich Faculty of Chemistry,
Institute of Catalysis Science and Technology, Technion − Israel Institute of Technology, Technion City,
32000 Haifa, Israel
| | - Haneen Simaan Yameen
- Schulich Faculty of Chemistry,
Institute of Catalysis Science and Technology, Technion − Israel Institute of Technology, Technion City,
32000 Haifa, Israel
| | - Boris Tumanskii
- Schulich Faculty of Chemistry,
Institute of Catalysis Science and Technology, Technion − Israel Institute of Technology, Technion City,
32000 Haifa, Israel
| | - Sabina-Alexandra Filimon
- Institut
für Anorganische
und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Matthias Tamm
- Institut
für Anorganische
und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Moris S. Eisen
- Schulich Faculty of Chemistry,
Institute of Catalysis Science and Technology, Technion − Israel Institute of Technology, Technion City,
32000 Haifa, Israel
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17
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Switzer JM, Travia NE, Steelman DK, Medvedev GA, Thomson KT, Delgass WN, Abu-Omar MM, Caruthers JM. Kinetic Modeling of 1-Hexene Polymerization Catalyzed by Zr(tBu-ONNMe2O)Bn2/B(C6F5)3. Macromolecules 2012. [DOI: 10.1021/ma300129n] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Jeffrey M. Switzer
- School
of Chemical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United
States
| | - Nicholas E. Travia
- School
of Chemical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United
States
| | - D. Keith Steelman
- School
of Chemical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United
States
| | - Grigori A. Medvedev
- School
of Chemical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United
States
| | - Kendall T. Thomson
- School
of Chemical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United
States
| | - W. Nicholas Delgass
- School
of Chemical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United
States
| | - Mahdi M. Abu-Omar
- School
of Chemical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United
States
| | - James M. Caruthers
- School
of Chemical Engineering and ‡Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United
States
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18
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Moscato BM, Zhu B, Landis CR. Mechanistic Investigations into the Behavior of a Labeled Zirconocene Polymerization Catalyst. Organometallics 2012. [DOI: 10.1021/om3000955] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Beth M. Moscato
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Bolin Zhu
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Clark R. Landis
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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19
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Affiliation(s)
- Massimiliano Delferro
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
| | - Tobin J. Marks
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, United States
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20
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Deuterium labeling and mechanistic insights in the polymerization of propylene promoted by benzamidinate complexes. Macromol Res 2010. [DOI: 10.1007/s13233-010-1013-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Christianson MD, Tan EHP, Landis CR. Stopped-Flow NMR: Determining the Kinetics of [rac-(C2H4(1-indenyl)2)ZrMe][MeB(C6F5)3]-Catalyzed Polymerization of 1-Hexene by Direct Observation. J Am Chem Soc 2010; 132:11461-3. [DOI: 10.1021/ja105107y] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Matthew D. Christianson
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706
| | - Emily H. P. Tan
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706
| | - Clark R. Landis
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706
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22
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Babushkin DE, Brintzinger HH. Reactive intermediates formed during olefin polymerization by methylalumoxane-activated ansa-zirconocene catalysts: identification of a chain-carrying intermediate by NMR methods. J Am Chem Soc 2010; 132:452-3. [PMID: 20020742 DOI: 10.1021/ja909157r] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Addition of 1-hexene to methylalumoxane-activated catalyst systems based on rac-Me(2)Si(ind)(2)ZrMe(2) causes, concurrent with polyhexene formation and diminution of the otherwise prevalent cation [rac-Me(2)Si(ind)(2)Zr(mu-Me)(2)AlMe(2)](+), formation of a hitherto unobserved species [rac-Me(2)Si(ind)(2)Zr(mu-R)(mu-Me)AlMe(2)](+), where R is a Zr-bound polyhexyl chain. As hexene is increasingly consumed, this cation decays, mainly back to [rac-Me(2)Si(ind)(2)Zr(mu-Me)(2)AlMe(2)](+) and, in part, to some species containing a Zr-bound allylic chain end.
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Affiliation(s)
- Dmitrii E Babushkin
- Boreskov Institute of Catalysis, Siberian Branch of Russian Academy of Science, Pr. Lavrentieva 5, Novosibirsk, RU-630090, Russia.
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23
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Novstrup KA, Travia NE, Medvedev GA, Stanciu C, Switzer JM, Thomson KT, Delgass WN, Abu-Omar MM, Caruthers JM. Mechanistic Detail Revealed via Comprehensive Kinetic Modeling of [rac-C2H4(1-indenyl)2ZrMe2]-Catalyzed 1-Hexene Polymerization. J Am Chem Soc 2009; 132:558-66. [PMID: 20030387 DOI: 10.1021/ja906332r] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Krista A. Novstrup
- School of Chemical Engineering and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Nicholas E. Travia
- School of Chemical Engineering and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Grigori A. Medvedev
- School of Chemical Engineering and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Corneliu Stanciu
- School of Chemical Engineering and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Jeffrey M. Switzer
- School of Chemical Engineering and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Kendall T. Thomson
- School of Chemical Engineering and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - W. Nicholas Delgass
- School of Chemical Engineering and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - Mahdi M. Abu-Omar
- School of Chemical Engineering and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - James M. Caruthers
- School of Chemical Engineering and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
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24
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Alonso-Moreno C, Lancaster SJ, Wright JA, Hughes DL, Zuccaccia C, Correa A, Macchioni A, Cavallo L, Bochmann M. Ligand Mobility and Solution Structures of the Metallocenium Ion Pairs [Me2C(Cp)(fluorenyl)MCH2SiMe3+···X−] (M = Zr, Hf; X = MeB(C6F5)3, B(C6F5)4). Organometallics 2008. [DOI: 10.1021/om800486p] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Carlos Alonso-Moreno
- Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, U.K., Dipartimento di Chimica, Università di Perugia, I-06123 Perugia, Italy, and Dipartimento di Chimica, Università di Salerno, I-84084 Fisciano, Italy
| | - Simon J. Lancaster
- Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, U.K., Dipartimento di Chimica, Università di Perugia, I-06123 Perugia, Italy, and Dipartimento di Chimica, Università di Salerno, I-84084 Fisciano, Italy
| | - Joseph A. Wright
- Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, U.K., Dipartimento di Chimica, Università di Perugia, I-06123 Perugia, Italy, and Dipartimento di Chimica, Università di Salerno, I-84084 Fisciano, Italy
| | - David L. Hughes
- Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, U.K., Dipartimento di Chimica, Università di Perugia, I-06123 Perugia, Italy, and Dipartimento di Chimica, Università di Salerno, I-84084 Fisciano, Italy
| | - Cristiano Zuccaccia
- Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, U.K., Dipartimento di Chimica, Università di Perugia, I-06123 Perugia, Italy, and Dipartimento di Chimica, Università di Salerno, I-84084 Fisciano, Italy
| | - Andrea Correa
- Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, U.K., Dipartimento di Chimica, Università di Perugia, I-06123 Perugia, Italy, and Dipartimento di Chimica, Università di Salerno, I-84084 Fisciano, Italy
| | - Alceo Macchioni
- Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, U.K., Dipartimento di Chimica, Università di Perugia, I-06123 Perugia, Italy, and Dipartimento di Chimica, Università di Salerno, I-84084 Fisciano, Italy
| | - Luigi Cavallo
- Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, U.K., Dipartimento di Chimica, Università di Perugia, I-06123 Perugia, Italy, and Dipartimento di Chimica, Università di Salerno, I-84084 Fisciano, Italy
| | - Manfred Bochmann
- Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, U.K., Dipartimento di Chimica, Università di Perugia, I-06123 Perugia, Italy, and Dipartimento di Chimica, Università di Salerno, I-84084 Fisciano, Italy
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25
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Babushkin DE, Panchenko VN, Timofeeva MN, Zakharov VA, Brintzinger HH. Novel Zirconocene Hydride Complexes in Homogeneous and in SiO2
-Supported Olefin-Polymerization Catalysts Modified with Diisobutylaluminum Hydride or Triisobutylaluminum. MACROMOL CHEM PHYS 2008. [DOI: 10.1002/macp.200800084] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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26
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Henderson LD, Piers WE. Ion pair symmetrization in metallocenium cations partnered with diborane derived borate counteranions. J Organomet Chem 2007. [DOI: 10.1016/j.jorganchem.2007.05.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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27
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Babushkin DE, Brintzinger HH. Modification of Methylaluminoxane-Activatedansa-Zirconocene Catalysts with Triisobutylaluminum—Transformations of Reactive Cations Studied by NMR Spectroscopy. Chemistry 2007; 13:5294-9. [PMID: 17385201 DOI: 10.1002/chem.200601801] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
When triisobutylaluminum (AliBu(3)) is added to solutions containing methylaluminoxane (MAO) and rac-[Me(2)Si(ind)(2)ZrCl(2)] (ind: indenyl) in C(6)D(6), NMR spectra show that methyl-bridged mixed-alkylaluminum dimers Al(mu-Me)(2)Me(4-x)iBu(x) predominate. These dimers react with MAO under partial transfer of isobutyl groups and induce a conversion of the initially prevailing cationic trimethylaluminum adduct rac-[Me(2)Si(ind)(2)Zr(mu-Me)(2)AlMe(2) (+)] to rac-[Me(2)Si(ind)(2)Zr(mu-Me)(2)AlMeiBu(+)] and rac-[Me(2)Si(ind)(2)Zr(mu-Me)(2)AliBu(2) (+)]. These species are unstable and release isobutene under formation of zirconocene hydrides.
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Affiliation(s)
- Dmitrii E Babushkin
- Boreskov Institute of Catalysis, Russian Academy of Science, Prospekt Akad.Lavrent'eva 5, 630090 Novosibirsk, Russia
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28
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Chapter 6 Active Centers in Transition Metal Catalysts and Mechanisms of Polymerization Reactions. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/s0167-2991(07)00006-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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29
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Coles SR, Clarkson GJ, Gott AL, Munslow IJ, Spitzmesser SK, Scott P. Half-Sandwich Group 4 Salicyloxazoline Catalysts. Organometallics 2006. [DOI: 10.1021/om060687h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stuart R. Coles
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., and INEOS Technologies, Rue de Ransbeek 310, 1120 Brussels, Belgium
| | - Guy J. Clarkson
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., and INEOS Technologies, Rue de Ransbeek 310, 1120 Brussels, Belgium
| | - Andrew L. Gott
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., and INEOS Technologies, Rue de Ransbeek 310, 1120 Brussels, Belgium
| | - Ian J. Munslow
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., and INEOS Technologies, Rue de Ransbeek 310, 1120 Brussels, Belgium
| | - Stefan K. Spitzmesser
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., and INEOS Technologies, Rue de Ransbeek 310, 1120 Brussels, Belgium
| | - Peter Scott
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K., and INEOS Technologies, Rue de Ransbeek 310, 1120 Brussels, Belgium
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30
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Landis CR, Christianson MD. Metallocene-catalyzed alkene polymerization and the observation of Zr-allyls. Proc Natl Acad Sci U S A 2006; 103:15349-54. [PMID: 17032772 PMCID: PMC1834834 DOI: 10.1073/pnas.0602704103] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Single-site polymerization catalysts enable exquisite control over alkene polymerization reactions to produce new materials with unique properties. Knowledge of catalyst speciation and fundamental kinetics are essential for full mechanistic understanding of zirconocene-catalyzed alkene polymerization. Currently the effect of activators on fundamental polymerization steps is not understood. Progress in understanding activator effects requires determination of fundamental kinetics for zirconocene catalysts with noncoordinating anions such as [B(C6F5)4]-. Kinetic NMR studies at low temperature demonstrate a very fast propagation rate for 1-hexene polymerization catalyzed by [(SBI)Zr(CH2SiMe3)][B(C6F5)4] [where SBI is rac-Me2Si(indenyl)2] with complete consumption of 1-hexene before the first NMR spectrum. Surprisingly, the first NMR spectrum reveals, aside from uninitiated catalyst, Zr-allyls as the sole catalyst-containing species. These Zr-allyls, which exist in two diastereomeric forms, have been characterized by physical and chemical methods. The mechanism of Zr-allyl formation was probed with a trapping experiment, leading us to favor a mechanism in which Zr-polymeryl undergoes beta-H transfer to metal without dissociation of coordinated alkene followed by sigma-bond metathesis to form H2 and Zr-allyl. Zr-allyl species undergo slow reactions with alkene but react rapidly with H2 to form hydrogenation products.
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Affiliation(s)
- Clark R Landis
- Chemistry Department, University of Wisconsin, 1101 University Avenue, Madison, WI 53706, USA.
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31
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Volkis V, Rodensky M, Lisovskii A, Balazs Y, Eisen MS. Stereoerror Formation in the Polymerization of Propylene Catalyzed by a Titanium Bis(benzamidinate) Dichloride Complex Activated by MAO. Organometallics 2006. [DOI: 10.1021/om060611l] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Victoria Volkis
- Department of Chemistry and Institute of Catalysis Science and Technology, TechnionIsrael Institute of Technology, Haifa 32000, Israel
| | - Michal Rodensky
- Department of Chemistry and Institute of Catalysis Science and Technology, TechnionIsrael Institute of Technology, Haifa 32000, Israel
| | - Anatolii Lisovskii
- Department of Chemistry and Institute of Catalysis Science and Technology, TechnionIsrael Institute of Technology, Haifa 32000, Israel
| | - Yael Balazs
- Department of Chemistry and Institute of Catalysis Science and Technology, TechnionIsrael Institute of Technology, Haifa 32000, Israel
| | - Moris S. Eisen
- Department of Chemistry and Institute of Catalysis Science and Technology, TechnionIsrael Institute of Technology, Haifa 32000, Israel
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32
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Correa A, Cavallo L. Dynamic Properties of Metallocenium Ion Pairs in Solution by Atomistic Simulations. J Am Chem Soc 2006; 128:10952-9. [PMID: 16910692 DOI: 10.1021/ja062407v] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report a molecular dynamics study of the dynamics and energetic of the [H(2)Si(Cp)(2)ZrMe(+)][MeB(C(6)F(5))(3)(-)], IP1, and [Me(2)Si(Cp)(2)ZrMe(+)][B(C(6)F(5))(4)(-)], IP2, ion pairs in benzene. The metrical parameters obtained for the IP1 ion pair are in excellent agreement with the NMR data reported for the strictly related [Me(2)Si(Cp)(2)ZrMe(+)][MeB(C(6)F(5))(3)(-)] ion pair (J. Am. Chem. Soc. 2004, 126, 1448). This validates the molecular modeling protocol we developed. Simulation of the IP2 ion pair suggests that the counterion oscillates between two geometries characterized by a different coordination pattern of the F atoms to the Zr cation. In one case the B(C(6)F(5))(4)(-) coordinates to the metal with two F atoms of the same aryl ring, whereas in the other case two F atoms of different aryl rings are involved in the coordination. Strong solvent reorganization occurs around IP1 and IP2, as well as around the two isolated cations. In the case of the two ion pairs solvent is never coordinated directly to the metal, whereas in the absence of the counterion one benzene molecule is coordinated to the metal through a cation-pi interaction. Free energy calculations result in ion pair free energies of separation of 36.8 and 23.3 kcal/mol for IP1 and IP2, respectively. Simulations with the Zr-B distance fixed at values > 7 A have been also performed. This mimics the situation occurring after counterion displacement by an inserting monomer molecule during olefin polymerization by the title catalysts.
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Affiliation(s)
- Andrea Correa
- Dipartimento di Chimica, Università di Salerno, Via Salvador Allende, Baronissi (SA), I-84081, Italy
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Stoebenau EJ, Jordan RF. Nonchelated Alkene and Alkyne Complexes of d0 Zirconocene Pentafluorophenyl Cations. J Am Chem Soc 2006; 128:8638-50. [PMID: 16802830 DOI: 10.1021/ja057524p] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper describes the generation and properties of nonchelated d(0) zirconocene-aryl-alkene and alkyne adducts that are stabilized by the presence of beta-SiMe(3) substituents on the substrates and the weak nucleophilicity of the -C(6)F(5) ligand. The cationic complexes [(C(5)H(4)R)(2)Zr(C(6)F(5))][B(C(6)F(5))(4)] (4a: R = H, 4b: R = Me) were generated by methide abstraction from (C(5)H(4)R)(2)Zr(C(6)F(5))Me by Ph(3)C(+). NMR studies show that 4a,b contain an o-CF...Zr dative interaction and probably coordinate a PhCl molecule in PhCl solution. Addition of allyltrimethylsilane (ATMS) to 4a,b in C(6)D(5)Cl solution at low temperature produces an equilibrium mixture of (C(5)H(4)R)(2)Zr(C(6)F(5))(H(2)C=CHCH(2)SiMe(3))(+) (7a,b), 4a,b, and free ATMS. Similarly, addition of propargyltrimethylsilane (PTMS) to 4a produces an equilibrium mixture of Cp(2)Zr(C(6)F(5))(HCCCH(2)SiMe(3))(+) (8a), 4a, and free PTMS. The NMR data for 7a,b,and 8a are consistent with highly unsymmetrical substrate coordination and substantial polarization of the substrate multiple bond with significant positive charge buildup at C(int) and negative charge buildup at C(term). PTMS binds to 4a more strongly than ATMS does. The ATMS adducts undergo nondissociative alkene face exchange ("alkene flipping"), i.e., exchange of the (C(5)H(4)R)(2)Zr(C(6)F(5))(+) unit between the two alkene enantiofaces without decomplexation of the alkene, on the NMR time scale.
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Affiliation(s)
- Edward J Stoebenau
- Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, IL 60637, USA
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Harney MB, Keaton RJ, Fettinger JC, Sita LR. Living Ziegler−Natta Polymerization by Early Transition Metals: Synthesis and Evaluation of Cationic Zirconium Alkyl Complexes Bearing β-Hydrogens as Models for Propagating Centers. J Am Chem Soc 2006; 128:3420-32. [PMID: 16522123 DOI: 10.1021/ja057866v] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis and characterization of a series of cationic zirconium and hafnium complexes with alkyl substituents bearing beta-hydrogens of general formula {(eta(5)-C5Me5)MR[N(Et)C(Me)N(t-Bu)]}[B(C6F5)4] [M = Zr; R = Et, n-Pr, i-Pr, n-Bu, i-Bu, and 2-ethylbutyl (5a-f) and M = Hf; R = i-Bu and t-Bu (6 and 7, respectively)] is described, including several isotopically labeled derivatives. The ability of these complexes to serve as model complexes for the living Ziegler-Natta polymerization of olefins that can be effected using the initiator 2a (R = Me in 5) has been addressed. The results obtained shed additional light on the steric and electronic factors that can contribute to the living character of a Ziegler-Natta polymerization based on an early transition metal initiator.
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Affiliation(s)
- Matthew B Harney
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
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Babushkin DE, Naundorf C, Brintzinger HH. Distinct methylalumoxane(MAO)-derived Me–MAO−anions in contact with a zirconocenium cation—a13C-NMR study. Dalton Trans 2006:4539-44. [PMID: 17016564 DOI: 10.1039/b611028m] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Zirconocenium cations of the type [(MeC5H4)2ZrMe]+, formed by excess methylalumoxane (MAO) from (MeC5H4)2ZrCl2 or (MeC5H4)2ZrMe2 with 13C-labelled ring ligands, are found to form ion pairs with two types of anions, Me-MAO(A)- and Me-MAO(B)-, which differ in their coordinative strengths: More strongly coherent ion pairs [(MeC5H4)2ZrMe+...Me-MAO(B)-] are converted to more easily separable ion pairs [(MeC5H4)2ZrMe+...Me-MAO(A)-] by a sufficient excess of MAO. These react with Al2Me6 to form outer-sphere ion pairs containing the cationic AlMe3 adduct [(MeC5H4)2Zr(mu-Me)2AlMe2]+; formation of the more easily separable ion pairs might be required also for polymerisation catalysis.
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Affiliation(s)
- Dmitrii E Babushkin
- Boreskov Institute of Catalysis, Russian Academy of Science, RU-630090, Novosibirsk, Russia.
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36
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Hannant MH, Wright JA, Lancaster SJ, Hughes DL, Horton PN, Bochmann M. The synthesis of new weakly coordinating diborate anions: anion stability as a function of linker structure and steric bulk. Dalton Trans 2006:2415-26. [PMID: 16705340 DOI: 10.1039/b515548g] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The successive addition of KCN and Ph3CCl to B(C6F4-C6F5-2)3 (PBB) affords triphenylmethyl salts of the [NC-PBB]- anion. By contrast, the analogous reaction with sodium dicyanamide followed by treatment with Ph(3)CCl leads to the zwitterionic aminoborane H2NB(C12F9)2C12F8, via nucleophilic attack on an o-F atom, together with CPh3[F-PBB]. Whereas treatment of [NC-PBB]- with either PBB or B(C6F5)3 fails to give isolable cyano-bridged diborates, the reaction of Me3SiNC-B(C6F5)3 with PBB in the presence of Ph3CCl affords [Ph3C][PBB-NC-B(C6F5)3]. Due to steric hindrance this anion is prone to borane dissociation. The longer linking group N(CN)2- gives the very voluminous anions [N[CNB(C6F5)3]2]- and [N(CN-PBB)2]-. A comparison of propylene polymerisations with rac-Me2Si(Ind)2ZrMe2 activated with the various boranes or trityl borates gives an anion-dependent activity sequence, in the order [NC-PBB]- < [MeB(C6F5)3]- < [MePBB]- approximately [PBB-NCB(C6F5)3]- approximately [N[CNB(C6F5)3]2]- < [F-PBB]-<< [B(C6F5)4]- < [N(CN-PBB)2]-. The anion [N(CN-PBB)2]- gives a catalyst productivity about 2500 times higher than that of [NC-PBB]- and exceeds that of [B(C6F5)4]- based catalysts. The van der Waals volumes and surface areas of the anions have been calculated and provide a rationale for the observed reactivity trends in polymerisation reactions.
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Affiliation(s)
- Mark H Hannant
- Wolfson Materials and Catalysis Centre, School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich, UKNR4 7TJ
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37
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Vatamanu M, Boden BN, Baird MC. An Investigation into the Identities and the Relative Concentrations of the Zr−Polymeryl Species Present during Ethylene and Propylene Polymerizations by Zirconocene-Based Ziegler Catalysts. Macromolecules 2005. [DOI: 10.1021/ma051947u] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mihaela Vatamanu
- Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Britta N. Boden
- Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada
| | - Michael C. Baird
- Department of Chemistry, Queen's University, Kingston, ON K7L 3N6, Canada
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38
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Lincoln AL, Wilmes GM, Waymouth RM. Dynamic NMR Studies of Cationic Bis(2-phenylindenyl)zirconium Pyridyl Complexes: Evidence for syn Conformers in Solution. Organometallics 2005. [DOI: 10.1021/om050473k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alice L. Lincoln
- Department of Chemistry, Stanford University, Stanford, California 94305-5080
| | - Gregg M. Wilmes
- Department of Chemistry, Stanford University, Stanford, California 94305-5080
| | - Robert M. Waymouth
- Department of Chemistry, Stanford University, Stanford, California 94305-5080
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Chirik PJ, Bercaw JE. Cyclopentadienyl and Olefin Substituent Effects on Insertion and β-Hydrogen Elimination with Group 4 Metallocenes. Kinetics, Mechanism, and Thermodynamics for Zirconocene and Hafnocene Alkyl Hydride Derivatives. Organometallics 2005. [DOI: 10.1021/om0580351] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paul J. Chirik
- Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125
| | - John E. Bercaw
- Arnold and Mabel Beckman Laboratories of Chemical Synthesis, California Institute of Technology, Pasadena, California 91125
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40
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Propene polymerization using ansa-metallocenium ions: Catalyst deactivation processes during monomer consumption and molecular structures of the products formed. Polyhedron 2005. [DOI: 10.1016/j.poly.2005.02.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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41
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Busico V, Cipullo R, Friederichs N, Linssen H, Segre A, Van Axel Castelli V, van der Velden G. H NMR Analysis of Chain Unsaturations in Ethene/1-Octene Copolymers Prepared with Metallocene Catalysts at High Temperature. Macromolecules 2005. [DOI: 10.1021/ma050620q] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Vincenzo Busico
- Dipartimento di Chimica, Università di Napoli “Federico II”, Via Cintia, 80126 Naples, Italy, SABIC EuroPetrochemicals R&D, P.O. Box 319, 6160 AH Geleen, The Netherlands, DSM Resolve, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Istituto di Metodologie Chimiche, CNR, M.B. 10, 00016 Monterotondo Stazione, Italy
| | - Roberta Cipullo
- Dipartimento di Chimica, Università di Napoli “Federico II”, Via Cintia, 80126 Naples, Italy, SABIC EuroPetrochemicals R&D, P.O. Box 319, 6160 AH Geleen, The Netherlands, DSM Resolve, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Istituto di Metodologie Chimiche, CNR, M.B. 10, 00016 Monterotondo Stazione, Italy
| | - Nic. Friederichs
- Dipartimento di Chimica, Università di Napoli “Federico II”, Via Cintia, 80126 Naples, Italy, SABIC EuroPetrochemicals R&D, P.O. Box 319, 6160 AH Geleen, The Netherlands, DSM Resolve, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Istituto di Metodologie Chimiche, CNR, M.B. 10, 00016 Monterotondo Stazione, Italy
| | - Harrie Linssen
- Dipartimento di Chimica, Università di Napoli “Federico II”, Via Cintia, 80126 Naples, Italy, SABIC EuroPetrochemicals R&D, P.O. Box 319, 6160 AH Geleen, The Netherlands, DSM Resolve, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Istituto di Metodologie Chimiche, CNR, M.B. 10, 00016 Monterotondo Stazione, Italy
| | - Annalaura Segre
- Dipartimento di Chimica, Università di Napoli “Federico II”, Via Cintia, 80126 Naples, Italy, SABIC EuroPetrochemicals R&D, P.O. Box 319, 6160 AH Geleen, The Netherlands, DSM Resolve, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Istituto di Metodologie Chimiche, CNR, M.B. 10, 00016 Monterotondo Stazione, Italy
| | - Valeria Van Axel Castelli
- Dipartimento di Chimica, Università di Napoli “Federico II”, Via Cintia, 80126 Naples, Italy, SABIC EuroPetrochemicals R&D, P.O. Box 319, 6160 AH Geleen, The Netherlands, DSM Resolve, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Istituto di Metodologie Chimiche, CNR, M.B. 10, 00016 Monterotondo Stazione, Italy
| | - Geert van der Velden
- Dipartimento di Chimica, Università di Napoli “Federico II”, Via Cintia, 80126 Naples, Italy, SABIC EuroPetrochemicals R&D, P.O. Box 319, 6160 AH Geleen, The Netherlands, DSM Resolve, P.O. Box 18, 6160 MD Geleen, The Netherlands, and Istituto di Metodologie Chimiche, CNR, M.B. 10, 00016 Monterotondo Stazione, Italy
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42
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Hagen CM, Vieille-Petit L, Laurenczy G, Süss-Fink G, Finke RG. Supramolecular Triruthenium Cluster-Based Benzene Hydrogenation Catalysis: Fact or Fiction? Organometallics 2005. [DOI: 10.1021/om048976y] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Collin M. Hagen
- Department of Chemistry, Colorado State University, Ft. Collins, Colorado 80523, Institut de Chimie, Université de Neuchâtel, Case postale 2, CH2007 Neuchâtel, Switzerland, and Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, BCH, CH-1015 Lausanne, Switzerland
| | - Ludovic Vieille-Petit
- Department of Chemistry, Colorado State University, Ft. Collins, Colorado 80523, Institut de Chimie, Université de Neuchâtel, Case postale 2, CH2007 Neuchâtel, Switzerland, and Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, BCH, CH-1015 Lausanne, Switzerland
| | - Gábor Laurenczy
- Department of Chemistry, Colorado State University, Ft. Collins, Colorado 80523, Institut de Chimie, Université de Neuchâtel, Case postale 2, CH2007 Neuchâtel, Switzerland, and Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, BCH, CH-1015 Lausanne, Switzerland
| | - Georg Süss-Fink
- Department of Chemistry, Colorado State University, Ft. Collins, Colorado 80523, Institut de Chimie, Université de Neuchâtel, Case postale 2, CH2007 Neuchâtel, Switzerland, and Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, BCH, CH-1015 Lausanne, Switzerland
| | - Richard G. Finke
- Department of Chemistry, Colorado State University, Ft. Collins, Colorado 80523, Institut de Chimie, Université de Neuchâtel, Case postale 2, CH2007 Neuchâtel, Switzerland, and Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, BCH, CH-1015 Lausanne, Switzerland
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43
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Vanka K, Xu Z, Ziegler T. Combined Density Functional Theory and Molecular Mechanics (QM/MM) Study of Single-Site Ethylene Polymerization and Chain Termination for the Catalysts [(C6R5NCH)C4H3N]2PrTi+ (R = F, H) and [bis(η5-1-indenyl)dimethylsilane]PrZr+ in the Presence of the Counterion CH3B(C6F5)3-. Organometallics 2005. [DOI: 10.1021/om0492808] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kumar Vanka
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - Zhitao Xu
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - Tom Ziegler
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada T2N 1N4
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44
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di Lena F, Quintanilla E, Chen P. Measuring rate constants for active species in the polymerization of ethylene by MAO-activated metallocene catalysts by electrospray ionization mass spectrometry. Chem Commun (Camb) 2005:5757-9. [PMID: 16307136 DOI: 10.1039/b511997a] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrospray ionization mass spectrometry (ESI-MS) of MAO-activated metallocene-catalyzed polymerizations quenched with carbodiimides provides a method for the determination of rate constants in Ziegler-Natta polymerizations.
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Affiliation(s)
- Fabio di Lena
- Laboratorium für Organische Chemie, ETH Zürich, Switzerland
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45
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46
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Stoebenau EJ, Jordan RF. Alkyne and Alkene Complexes of a d0 Zirconocene Aryl Cation. J Am Chem Soc 2004; 126:11170-1. [PMID: 15355096 DOI: 10.1021/ja045794m] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The generation and properties of nonchelated Zr-aryl-alkyne and Zr-aryl-alkene complexes that are stabilized by the presence of beta-Si-substituents in the alkyne and alkene ligands and fluorination of the aryl ligand are described. Reaction of [Cp'2Zr(OtBu)(ClCD2Cl)][B(C6F5)4] (1, Cp' = C5H4Me) with alkyne and alkene substrates (L) generates Cp'2Zr(OtBu)(L)+ adducts (L = HCCCH2SiMe3 (2); H2C=CHCH2SiMe3 (3); HCCMe (4); H2C=CHCH2CMe3 (5)). Equilibrium constants for substrate binding (Keq = [Zr-L][1]-1[L]-1; CD2Cl2, -89 degrees C) are much larger for the beta-Si-substituted compounds 2 (1.0(2) x 105 M-1) and 3 (1.7(4) x 103 M-1) than for hydrocarbon analogues 4 (3.6(7) x 102 M-1) and 5 (1.9(1) M-1), which is ascribed to beta-Si stabilization of the partial positive charge on Cint of the bound substrate. [Cp2Zr(C6F5)][B(C6F5)4] (7, Cp = C5H5) was generated by the reaction of Cp2Zr(C6F5)Me with [Ph3C][B(C6F5)4] in C6D5Cl. Reaction of 7 with alkyne and alkene substrates (L) generates Cp2Zr(C6F5)(L)+ adducts (L = HCCCH2SiMe3 (8); H2C=CHCH2SiMe3 (10)). No insertion of the substrate into the Zr-C6F5 bond is observed in 8 (at -38 degrees C) or 10 (up to 22 degrees C). The allyltrimethylsilane ligand in 10 undergoes nondissociative alkene face exchange ("alkene flipping", i.e., exchange of the Cp2Zr(C6F5)+ unit between the two alkene enantiofaces without alkene dissociation), with a first-order rate constant kflip = 23(1) s-1 (C6D5Cl, -38 degrees C). 10 also undergoes slower reversible decomplexation of the alkene (kdissoc = 5.0(8) s-1; C6D5Cl, -38 degrees C).
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Affiliation(s)
- Edward J Stoebenau
- Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, USA
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47
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Landis CR, Sillars DR, Batterton JM. Reactivity of Secondary Metallocene Alkyls and the Question of Dormant Sites in Catalytic Alkene Polymerization. J Am Chem Soc 2004; 126:8890-1. [PMID: 15264808 DOI: 10.1021/ja047547o] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reactivity of [rac-(C2H4(1-indenyl)2)Zr(n-butyl)][MeB(C6F5)3] (4), [rac-(C2H4(1-indenyl)2)Zr(sec-butyl)][MeB(C6F5)3] (5), and [rac-(C2H4(1-indenyl)2)Zr(polypropenyl)][MeB(C6F5)3] with propene, ethene, and hydrogen was studied by low-temperature (<-40 degrees C) 1H and 13C NMR spectroscopy in toluene solutions. In contrast with previous suggestions that 2 degrees zirconium alkyl species such as 5 are dormant sites, these measurements demonstrate reactivity of 2 degrees zirconium alkyls with propene and ethene comparable to the 1 degrees zirconium alkyl species 4 and [rac-(C2H4(1-indenyl)2)Zr(polypropenyl)][MeB(C6F5)3]. Because 2,1-insertion of propene is an infrequent event, these results preclude significant accumulation of catalyst in the form of 2 degrees zirconium alkyls for this metallocene and counterion. The reactivity of 5 with hydrogen is at least 2 orders of magnitude faster than other 1 degrees zirconium alkyls. Such high reactivity accounts for the puzzlingly high fraction of butyl end groups in prior hydrooligomerization studies and implies that catalyst responsivity to H2 as a molecular weight control agent correlates with the regioselectivity of the catalyst.
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Affiliation(s)
- Clark R Landis
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, USA.
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48
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Cho ES, Won YC, Lee SY, Lee BY, Shin DM, Chung YK. Syntheses, characterizations, and olefin polymerizations of methylene-bridged 1,3-dimethylcyclopentadienyl/indenyl and 1,3-dimethylcyclopentadienyl/tetrahydroindenyl zirconium complexes. Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2004.01.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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49
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Harney MB, Keaton RJ, Sita LR. End-Group-Confined Chain Walking within a Group 4 Living Polyolefin and Well-Defined Cationic Zirconium Alkyl Complexes for Modeling This Behavior. J Am Chem Soc 2004; 126:4536-7. [PMID: 15070369 DOI: 10.1021/ja0496975] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Living polymers derived from the polymerization of 1-butene using the cationic zirconium initiator, {Cp*ZrMe[N(Et)C(Me)-N(tBu)]}[B(C6F5)4] (Cp* = eta5-C5Me5) (1), have been shown to undergo end-group-confined chain walking that is competitive with direct beta-hydride elimination and chain release at -10 degrees C. The well-defined complexes, {Cp*Zr(iBu)[N(Et)C(Me)N(tBu)]}[B(C6F5)4] (2) and {Cp*Zr(2-ethylbutyl)[N(Et)C(Me)N(tBu)]}[B(C6F5)4] (3), were prepared, and each was found to possess a strong beta-hydrogen agostic interaction that is absent in the living polymer. The isotopically single- and double-labeled derivatives, {Cp*Zr(2-d-2-methylpropyl)[N(Et)C(Me)N(tBu)]}[B(C6F5)4] (2') and {Cp*Zr(1-13C-2-d-2-methylpropyl)[N(Et)C(Me)N(tBu)]}[B(C6F5)4] (2' '), were also prepared and found to undergo isotopic label scrambling at 0 degrees C. For 2' ', the observation that after scrambling each deuterium label is located on a 13C-labeled carbon atom is consistent with the Busico mechanism for chain-end epimerization rather than the Resconi mechanism. Decomposition of 3 yielded olefinic products also consistent with chain walking prior to beta-hydride elimination and chain release. Finally, the unexpected decrease in stability of the living polymer relative to that of the model complexes reveals the importance of subtle differences in steric and electronic factors in controlling beta-hydride elimination and chain release.
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Affiliation(s)
- Matthew B Harney
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA
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50
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Chen MC, Roberts JAS, Marks TJ. Marked Counteranion Effects on Single-Site Olefin Polymerization Processes. Correlations of Ion Pair Structure and Dynamics with Polymerization Activity, Chain Transfer, and Syndioselectivity. J Am Chem Soc 2004; 126:4605-25. [PMID: 15070378 DOI: 10.1021/ja036288k] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Counteranion effects on the rate and stereochemistry of syndiotactic propylene enchainment by the archetypal C(s)-symmetric precatalyst [Me(2)C(Cp)(Flu)]ZrMe(2) (1; Cp = C(5)H(4); Flu = C(13)H(8), fluorenyl) are probed using the cocatalysts MAO (2), B(C(6)F(5))(3) (3)(,) B(2-C(6)F(5)C(6)F(4))(3) (4)(,) Ph(3)C(+)B(C(6)F(5))(4)(-) (5), and Ph(3)C(+)FAl(2-C(6)F(5)C(6)F(4))(3)(-) (6), offering greatly different structural and ion pairing characteristics. Reaction of 1 with 3 affords [Me(2)C(Cp)(Flu)]ZrMe(+) MeB(C(6)F(5))(3)(-) (7). In the case of 4, this reaction leads to formation the micro-methyl dinuclear diastereomers [([Me(2)C(Cp)(Flu)]ZrMe)(2)(micro-Me)](+) MeB(2-C(6)F(5)C(6)F(4))(3)(-) (8). A similar reaction with 6 results in diastereomeric [Me(2)C(Cp)(Flu)]ZrMe(+) FAl(2-C(6)F(5)C(6)F(4))(3)(-) (10) ion pairs. The molecular structures of 7 and 10 have been determined by single-crystal X-ray diffraction. Reorganization pathways available to these species have been examined using EXSY and dynamic NMR, revealing that the cation-MeB(C(6)F(5))(3)(-) interaction is considerably weaker/more mobile than in the FAl(2-C(6)F(5)C(6)F(4))(3)(-)-derived analogue. Polymerizations mediated by 1 in toluene over the temperature range of -10 degrees to +60 degrees C and at 1.0-5.0 atm propylene pressure (at 60 degrees C) reveal that activity, product syndiotacticity, m and mm stereodefect generation, and chain transfer processes are highly sensitive to the nature of the ion pairing. Thus, the complexes activated with 4 and 5, having the weakest ion pairing, yield the highest estimated propagation rates, while with 6, having the strongest pairing, yields the lowest. The strongly coordinating, immobile FAl(2-C(6)F(5)C(6)F(4))(3)(-) anion produces the highest/least temperature-dependent product syndiotacticity, lowest/least temperature-dependent m stereodefect abundance, and highest product molecular weight. These polypropylene microstructural parameters, and also M(w), are least sensitive to increased propylene pressure for FAl(2-C(6)F(5)C(6)F(4))(3)(-), but highest with MeB(C(6)F(5))(3)(-). In general, mm stereodefect production is only modestly anion-sensitive; [propylene] dependence studies reveal enantiofacial propylene misinsertion to be the prevailing mm-generating process in all systems at 60 degrees C, being most dominant with 6, where mm stereodefect abundance is lowest. For 1,3-dichlorobenzene as the polymerization solvent, product syndiotacticity, as well as m and mm stereodefects, become indistinguishable for all cocatalysts. These observations are consistent with a scenario in which ion pairing modulates the rates of stereodefect generating processes relative to monomer enchainment, hence net enchainment syndioselectivity, and also dictates the rate of termination relative to propagation and the preferred termination pathway. In comparison to 3-6, propylene polymerization mediated by MAO (2) + 1 in toluene reveals an estimated ordering in site epimerization rates as 5 > 4 > 2 > 3 > 6, while product syndiotacticities rank as 6 > 2 > 5 approximately 4 > 3.
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Affiliation(s)
- Ming-Chou Chen
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113, USA
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