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Mundil R, Bravo C, Merle N, Zinck P. Coordinative Chain Transfer and Chain Shuttling Polymerization. Chem Rev 2024; 124:210-244. [PMID: 38085864 DOI: 10.1021/acs.chemrev.3c00440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Coordinative chain transfer polymerization, CCTP, is a degenerative chain transfer polymerization process that has a wide range of applications. It allows a highly controlled synthesis of polyolefins, stereoregular polydienes, and stereoregular polystyrene, including (stereo)block as well as statistical copolymers thereof. It also shows a green character by allowing catalyst economy during the synthesis of such polymers. CCTP notably allows the end functionalization of both the commodity and stereoregular specialty polymers aforementionned, control of the composition of statistical copolymers without adjusting the feed, and quantitative formation of 1-alkenes from ethene. A one-pot one-step synthesis of the original multiblock microstructures and architectures by chain shuttling polymerization (CSP) is also an asset of CCTP. This methodology takes advantage of the simultaneous presence of two catalysts of different selectivity toward comonomers that produce blocks of different composition/microstructure, while still allowing the chain transfer. This affords the production of highly performant functional polymers, such as thermoplastic elastomers and adhesives, among others. This approach has been extended to cyclic esters' and ethers' ring-opening polymerization, providing new types of multiblock microstructure. The present Review provides the state of the art in the field with a focus on the last 10 years.
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Affiliation(s)
- Robert Mundil
- Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova, 2030, 128 40 Prague 2, Czech Republic
| | - Catarina Bravo
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France
| | - Nicolas Merle
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France
| | - Philippe Zinck
- Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France
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Ding A, Fang L, Zhang C, Liu H, Zhang X, Liao J. Neodymium-Mediated Coordinative Chain Transfer Polymerization of Isoprene in the Presence of External Donors. Molecules 2023; 28:7364. [PMID: 37959785 PMCID: PMC10648742 DOI: 10.3390/molecules28217364] [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: 09/16/2023] [Revised: 10/08/2023] [Accepted: 10/10/2023] [Indexed: 11/15/2023] Open
Abstract
Nd-based polydiene elastomers, including NdIR and NdBR, are regarded as indispensable key raw materials in preparing green tires with excellent performance capabilities, but their wide application is still limited by the relative higher cost of Nd precatalysts. Nd-mediated coordinative chain transfer polymerization (CCTP) of diene provides an effective strategy to reduce the precatalyst cost, because this method involves very high atom economy, i.e., each Nd molecule can generate multiple polymer chains. Nevertheless, all possible factors that could influence such CCTP behaviors are still mostly unexplored to date. In this report, the basic chemistry on the influence of external donors on the overall CCTP behaviors of isoprene was established for the first time. It was found that increasing the amount of external donors had a negative influence on the chain transfer efficiencies, resulting in gradually decreasing atom economies. Catalyst addition order studies revealed that the coordination of donors with cationic Nd active species, rather than alkylaluminium CTAs, contributed mostly to such decreased efficiencies. Moreover, it was found that when the ratio of donors and Nd compounds was higher than 1.0, the CCTP behaviors were corrupted, resulting in polymers with broad distributions, as well as resulting in low atom economies; nevertheless, when the ratio was lower than 0.5, the system still displayed CCTP characteristics, implying that the critical ratio for maintaining the CCTP was 0.5. Additionally, when such a ratio was 0.01, the high atom economy was almost the same as donor-free CCTP systems. Detailed kinetic studies at such a ratio demonstrated that the donor-contained system proceeded in a well-controlled manner, as concluded from the good linear relationship between the Mn of the PIps against the polymer yields, as well as the good linearity between the Mn against the (IP)/(Nd) ratios. Such maintained CCTP properties also allowed for seeding two-step polymerizations to prepare diblock copolymers with precisely controlled molecular weights. Expanding the types of donors to more phosphine, oxygen, and nitrogen containing compounds showed that they also affected the CCTP behaviors depending on their steric and electronic properties.
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Affiliation(s)
- Aiwu Ding
- School of Life Sciences, Hainan University, Haikou 570228, China;
- China Hainan Rubber Industry Group Co., Ltd., Haikou 570106, China
| | - Liang Fang
- Key Laboratory of Rubber-Plastics, Ministry of Education, Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, Qingdao 266061, China; (C.Z.); (H.L.); (X.Z.)
| | - Chunyu Zhang
- Key Laboratory of Rubber-Plastics, Ministry of Education, Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, Qingdao 266061, China; (C.Z.); (H.L.); (X.Z.)
| | - Heng Liu
- Key Laboratory of Rubber-Plastics, Ministry of Education, Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, Qingdao 266061, China; (C.Z.); (H.L.); (X.Z.)
| | - Xuequan Zhang
- Key Laboratory of Rubber-Plastics, Ministry of Education, Shandong Provincial Key Laboratory of Rubber-Plastics, Qingdao University of Science & Technology, Qingdao 266061, China; (C.Z.); (H.L.); (X.Z.)
| | - Jianhe Liao
- School of Materials Science and Engineering, Hainan University, Haikou 570228, China
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Abstract
The number of rare earth (RE) starting materials used in synthesis is staggering, ranging from simple binary metal-halide salts to borohydrides and "designer reagents" such as alkyl and organoaluminate complexes. This review collates the most important starting materials used in RE synthetic chemistry, including essential information on their preparations and uses in modern synthetic methodologies. The review is divided by starting material category and supporting ligands (i.e., metals as synthetic precursors, halides, borohydrides, nitrogen donors, oxygen donors, triflates, and organometallic reagents), and in each section relevant synthetic methodologies and applications are discussed.
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Affiliation(s)
- Fabrizio Ortu
- School of Chemistry, University of Leicester, LE1 7RH Leicester, U.K.
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Rinke P, Görls H, Kretschmer R. Calcium and Magnesium Bis(β-diketiminate) Complexes: Impact of the Alkylene Bridge on Schlenk-Type Rearrangements. Inorg Chem 2021; 60:5310-5321. [PMID: 33667337 DOI: 10.1021/acs.inorgchem.1c00301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Dinuclear heteroleptic alkaline-earth-metal complexes are interesting synthetic targets because the close proximity of two metals allows for cooperative effects. However, these complexes are also prone to undergoing Schlenk-type rearrangements, affording less-active homoleptic complexes. Here we present the metalation of bis(β-diketimine) ligands possessing flexible bridging groups, i.e., 1,2-ethylene, 1,3-propylene, and trans-1,2-cyclohexylene, using calcium and magnesium precursors. Four mononuclear homoleptic calcium complexes were obtained, highlighting the pronounced tendency of calcium to undergo Schlenk-like redistributions. In the case of magnesium, however, the bridging group plays a crucial role, yielding seven dinuclear heteroleptic complexes but also one mononuclear and one dinuclear homoleptic complexes. In addition, a trinuclear mixed heteroleptic-homoleptic magnesium complex, which is a rare example of an intermediate of the Schlenk equilibrium, was isolated.
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Affiliation(s)
- Philipp Rinke
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany.,Jena Center for Soft Matter, Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
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Ren W, Zhang S, Xu Z, Ma X. Reactivity of a β-diketiminate-supported magnesium alkyl complex toward small molecules. Dalton Trans 2019; 48:3109-3115. [PMID: 30768120 DOI: 10.1039/c9dt00090a] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The reactivity of the magnesium alkyl {[HC(C(Me)N-2,6-iPr2C6H3)2]Mg(nBu)}2 (1) toward various small molecules provides access to a variety of magnesium derivatives. For example, the insertion of elemental chalcogens (S8 and Se8) into the Mg-C bond of complex 1 gives the dimeric magnesium thiolate {[HC(C(Me)N-2,6-iPr2C6H3)2]Mg(μ-SnBu)}2 (2), magnesium selenolate [HC(C(Me)N-2,6-iPr2C6H3)2]Mg(SenBu)(THF) (3), and magnesium diselenolate [HC(C(Me)N-2,6-iPr2C6H3)2]Mg(Se2nBu)(THF) (4). Meanwhile, compound 4 can be readily obtained by further insertion of one selenium atom into complex 3. Moreover, the reactions of complex 1 with diphenyl dichalcogenides (PhSSPh and PhSeSePh) by σ bond metathesis afford the corresponding magnesium phenyl chalcogenolates [HC(C(Me)N-2,6-iPr2C6H3)2]Mg(EPh)(THF) (E = S 5, Se 6) concomitant with PhEnBu release. Furthermore, the treatment of complex 1 with benzonitrile and phenyl isothiocyanate produces the serendipitous magnesium-1-azaallyl complex [HC(C(Me)N-2,6-iPr2C6H3)2]Mg(N(H)C(Ph)[double bond, length as m-dash]CHC3H7)(DME) (7) and the diimino-thioamidato magnesium compound {κ3-N,N',N''-(ArNCMe)2[N(Ph)CS]CH}Mg[(Ph)NC(nBu)S] (8) (Ar = 2,6-iPr2C6H3). In addition, deprotonation occurs between compound 1 and 1-methylimidazole to generate the imidazolyl complex {[HC(C(Me)N-2,6-iPr2C6H3)2]Mg(μ-Im)}2 (9) (Im = 2-N-methylimidazolyl). These results indicated that the butylmagnesium complex 1 possesses high activity toward small molecules and revealed several unusual transformations. All the new compounds were characterized by various spectroscopic methods, and their solid-state structures were further confirmed by single-crystal X-ray diffraction analyses.
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Affiliation(s)
- Wenshan Ren
- College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
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Synthesis and structural characterization of lanthanum and cerium substituted cyclopentadienyl borohydride complexes. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2017.09.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Edelmann FT. Lanthanides and actinides: Annual survey of their organometallic chemistry covering the year 2016. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.02.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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