1
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Sumrit P, Kamavichanurat S, Joopor W, Wattanathana W, Nakornkhet C, Hormnirun P. Aluminium complexes of phenoxy-azo ligands in the catalysis of rac-lactide polymerisation. Dalton Trans 2024. [PMID: 39091186 DOI: 10.1039/d4dt01758g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Fourteen new phenoxy-azo aluminium complexes comprising two series, namely, dimethyl{phenoxy-azo}aluminium complexes 1a-7a and monomethyl{phenoxy-azo}aluminium complexes 1b-7b, were successfully synthesised and characterised. The molecular structure of complex 4a, determined using X-ray diffraction analysis, displayed a distorted tetrahedral geometry. The 1H NMR spectrum of complex 5b revealed fluxional behaviour caused by isomeric transformation that occurs in the solution at room temperature. The activation parameters determined by lineshape analysis of variable-temperature 1H NMR spectra in toluene-d8 are as follows: ΔH‡ = 70.05 ± 1.19 kJ mol-1, ΔS‡ = 21.78 ± 3.58 J mol-1 K-1 and ΔG‡ (298 K) = 63.56 ± 0.11 kJ mol-1. All aluminium complexes are active initiators for the ring-opening polymerisation of rac-lactide, and the polymerisations proceeded in a controlled manner and were living. In comparison, the catalytic activity of the dimethyl{phenoxy-azo}aluminium complexes was insignificantly different from that of the corresponding monomethyl{phenoxy-azo}aluminium complexes. The steric factor of the ortho-phenoxy substituent was observed to exert a decelerating effect on the catalytic rate. Kinetic investigations revealed first-order dependency on both monomer and initiator concentrations. Comparative catalytic investigations conducted on phenoxy-azo aluminium and phenoxy-imine aluminium complexes revealed that the former complexes exhibited lower catalytic activity.
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Affiliation(s)
- Pattarawut Sumrit
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
- Centre for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, Kasetsart University, Bangkok 10900, Thailand
| | - Sirawan Kamavichanurat
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
- Centre for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, Kasetsart University, Bangkok 10900, Thailand
| | - Wasan Joopor
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
- Centre for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, Kasetsart University, Bangkok 10900, Thailand
| | - Worawat Wattanathana
- Department of Materials Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900, Thailand
| | - Chutikan Nakornkhet
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
- Centre for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, Kasetsart University, Bangkok 10900, Thailand
| | - Pimpa Hormnirun
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Centre of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
- Centre for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, Kasetsart University, Bangkok 10900, Thailand
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2
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Zaky MS, Wirotius AL, Coulembier O, Guichard G, Taton D. Reaching High Stereoselectivity and Activity in Organocatalyzed Ring-Opening Polymerization of Racemic Lactide by the Combined Use of a Chiral (Thio)Urea and a N-Heterocyclic Carbene. ACS Macro Lett 2022; 11:1148-1155. [PMID: 36067070 DOI: 10.1021/acsmacrolett.2c00457] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Stereochemical control during polymerization is a key strategy of polymer chemistry to achieve semicrystalline engineered plastics. The stereoselective ring-opening polymerization (ROP) of racemic lactide (rac-LA), which can lead to highly isotactic polylactide (PLA), is one of the emblematic examples in this area. Surprisingly, stereoselective ROP of rac-LA employing chiral organocatalysts has been under-leveraged. Here we show that a commercially available chiral thiourea (TU1), or its urea homologue (U1), can be used in conjunction with an appropriately selected N-heterocyclic carbene (NHC) to trigger the stereoselective ROP of rac-LA at room temperature in toluene. Both a high organic catalysis activity (>90% monomer conversion in 5-9 h) and a high stereoselectivity (probability of formation of meso dyads, Pm, in the range 0.82-0.93) can be achieved by thus pairing a NHC and a chiral amino(thio)urea. The less sterically hindered and the more basic NHC, that is, a NHC bearing tert-butyl substituents (NHCtBu), provides the highest stereoselectivity when employed in conjunction with the chiral TU1 or U1. This asymmetric organic catalysis strategy, as applied here in polymerization chemistry, further expands the field of possibilities to achieve bioplastics with adapted thermomechanical properties.
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Affiliation(s)
- Mohamed Samir Zaky
- Laboratoire de Chimie des Polymères Organiques (LCPO), UMR 5629, Université de Bordeaux, INP-ENSCBP, 16 av, Pey Berland, 33607 PESSAC Cedex France
| | - Anne-Laure Wirotius
- Laboratoire de Chimie des Polymères Organiques (LCPO), UMR 5629, Université de Bordeaux, INP-ENSCBP, 16 av, Pey Berland, 33607 PESSAC Cedex France
| | - Olivier Coulembier
- Center of Innovation and Research in Materials and Polymers (CIRMAP), Laboratory of Polymeric and Composite Materials, University of Mons, Mons B-7000, Belgium
| | - Gilles Guichard
- Univ. Bordeaux, CNRS, CBMN, UMR 5248, Institut Européen de Chimie et Biologie, 2 rue Robert Escarpit, F-33607 Pessac, France
| | - Daniel Taton
- Laboratoire de Chimie des Polymères Organiques (LCPO), UMR 5629, Université de Bordeaux, INP-ENSCBP, 16 av, Pey Berland, 33607 PESSAC Cedex France
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3
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Stewart J, Fuchs M, Payne J, Driscoll O, Kociok-Köhn G, Ward BD, Herres-Pawlis S, Jones MD. Simple Zn(ii) complexes for the production and degradation of polyesters. RSC Adv 2022; 12:1416-1424. [PMID: 35425174 PMCID: PMC8979053 DOI: 10.1039/d1ra09087a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 11/21/2022] Open
Abstract
Nine new complexes based on thioether appended iminophenolate (ONS) ligands have been prepared and fully characterized in solution by NMR spectroscopy. Solid-state structures were also obtained for seven complexes. In solution, all complexes were monomeric. The complexes were highly active for the polymerization of purified rac-lactide ([M] : [Zn] : [BnOH] = 10 000 : 1 : 30 at 180 °C) reaching TOF values up to 250 000 h−1. The kinetics of the polymerization have been probed by in situ Raman spectroscopy. The rate of reaction was dramatically reduced using technical grade rac-lactide with increased initiator loading. To move towards a circular economy, it is vital that catalysts are developed to facilitate chemical recycling of commodity and emerging polymeric materials. In this vein, the complexes have been assessed for their ability to break down poly(lactic acid) and poly(ethylene terephthalate). The results from both the polymerization and degradation reactions are discussed in terms of ligand functionality. Nine new complexes based on thioether appended iminophenolate (ONS) ligands have been prepared and fully characterized in solution by NMR spectroscopy.![]()
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Affiliation(s)
- Jack Stewart
- Department of Chemistry, University of Bath, Claverton Down, Bath BA27AY, UK
| | - Martin Fuchs
- Lehrstuhl für Bioanorganische Chemie, Institut für Anorganische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Jack Payne
- Department of Chemistry, University of Bath, Claverton Down, Bath BA27AY, UK
| | - Oliver Driscoll
- Department of Chemistry, University of Bath, Claverton Down, Bath BA27AY, UK
| | | | - Benjamin D. Ward
- Department of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK
| | - Sonja Herres-Pawlis
- Lehrstuhl für Bioanorganische Chemie, Institut für Anorganische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Matthew D. Jones
- Department of Chemistry, University of Bath, Claverton Down, Bath BA27AY, UK
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4
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Tschan MJL, Gauvin RM, Thomas CM. Controlling polymer stereochemistry in ring-opening polymerization: a decade of advances shaping the future of biodegradable polyesters. Chem Soc Rev 2021; 50:13587-13608. [PMID: 34786575 DOI: 10.1039/d1cs00356a] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review highlights recent developments in the field of biodegradable polymeric materials intended to replace non-degradable conventional plastics, focusing on studies from the last ten years involving the stereoselective ring-opening polymerization of cyclic esters. This encompasses exciting advances in both catalyst design and monomer scope. Notably, the last decade has seen the emergence of metal-free stereocontrolled ROP for instance, as well as the synthesis and stereocontrolled polymerization of new types of chiral monomers. This study will emphasize recent stereoselective polymerization catalysts and chiral monomers and will focus on stereocontrol quantification, the mechanisms of stereocontrol and their differentiation if reported and studied for a specific catalyst system.
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Affiliation(s)
- Mathieu J-L Tschan
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, 75005 Paris, France.
| | - Régis M Gauvin
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, 75005 Paris, France.
| | - Christophe M Thomas
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, 75005 Paris, France.
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5
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Kosuru SR, Lai FJ, Chang YL, Li CY, Lai YC, Ding S, Wu KH, Chen HY, Lo YH. Collaboration between Trinuclear Aluminum Complexes Bearing Bipyrazoles in the Ring-Opening Polymerization of ε-Caprolactone. Inorg Chem 2021; 60:10535-10549. [PMID: 34232620 DOI: 10.1021/acs.inorgchem.1c01192] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Trinuclear aluminum complexes bearing bipyrazoles were synthesized, and their catalytic activity for ε-caprolactone (CL) polymerization was investigated. DBu2Al3Me5 exhibited higher catalytic activity than did the dinuclear aluminum complex LBu2Al2Me4 (16 times as high for CL polymerization; [CL]:[DBu2Al3Me5]:[BnOH] = 100:0.5:5, [DBu2Al3Me5] = 10 mM, conversion 93% after 18 min at room temperature). Density functional theory calculations revealed a polymerization mechanism in which CL first approached the central Al atom and then moved to an external Al. The coordinated CL ring was opened because the repulsion of two tert-butyl groups on the ligands pushed an alkoxide initiator on an external Al to initiate CL. In these trinuclear Al catalysts, the central Al plays a role in monomer capture and then collaborates with the external Al to activate CL, accelerating polymerization.
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Affiliation(s)
- Someswara Rao Kosuru
- Department of Medicinal and Applied Chemistry, Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
| | - Feng-Jie Lai
- Department of Dermatology, Chi Mei Medical Center, Tainan, Taiwan, Republic of China.,Center for General Education, Southern Taiwan University of Science and Technology, Tainan, Taiwan, Republic of China
| | - Yu-Lun Chang
- Department of Medicinal and Applied Chemistry, Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
| | - Chen-Yu Li
- Department of Medicinal and Applied Chemistry, Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
| | - Yi-Chun Lai
- Department of Medicinal and Applied Chemistry, Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
| | - Shangwu Ding
- Department of Medicinal and Applied Chemistry, Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China.,Department of Chemistry, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan, Republic of China
| | - Kuo-Hui Wu
- Department of Chemistry, National Central University, Taoyuan 32001, Taiwan, Republic of China
| | - Hsuan-Ying Chen
- Department of Medicinal and Applied Chemistry, Drug Development and Value Creation Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China.,Department of Chemistry, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan, Republic of China.,Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan, Republic of China
| | - Yung-Han Lo
- Department of Chemistry, Faculty of Science and Technology, Keio University, Minato City 108-8345, Tokyo, Japan
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6
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Macrocycles in dual role: ancillary ligands in metal complexes and organocatalysts for the ring-opening polymerization of lactide. J INCL PHENOM MACRO 2021. [DOI: 10.1007/s10847-021-01045-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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7
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Wan Y, Bai Y, Xu H, He J, Zhang Y. Highly Isoselective Ring-Opening Polymerization of rac-Lactide Using Chiral Binuclear Aluminum Catalyst. Macromol Rapid Commun 2020; 42:e2000491. [PMID: 33200483 DOI: 10.1002/marc.202000491] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 10/04/2020] [Indexed: 12/26/2022]
Abstract
The microstructure can significantly affect the physical and mechanical properties of polymers. Five chiral binuclear aluminum methyl complexes (rac1 to rac5) are synthesized by using chiral binaphthalene diamine ligand and characterized by both 1 H and 13 C NMR spectroscopy. The crystal structures of rac3 and rac5 are also identified by single crystal X-ray diffraction. In the presence of i PrOH initiator, these aluminum complexes catalyze the ring-opening polymerization (ROP) of rac-lactide (rac-LA) in a controlled manner and produce polymers with high to excellent isoselectivity (Pm up to 0.93). Even with a catalyst loading as low as 0.1%, polylactide with a Pm of 0.83 can still be obtained. Kinetic studies reveal the first-order dependence on monomer concentration whereas kinetic resolution polymerization provides the evidence to support that these binuclear aluminum catalysts catalyzed ROP of rac-LA adopts enantiomorphic site control mechanism. Furthermore, this strategy can also be applied to the ROP of both ε-caprolactone and δ-valeroactone.
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Affiliation(s)
- Yi Wan
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012, China
| | - Yun Bai
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012, China
| | - Hai Xu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012, China
| | - Jianghua He
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012, China
| | - Yuetao Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, Jilin, 130012, China
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8
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Gazzotti S, Ortenzi MA, Farina H, Disimino M, Silvani A. Carvacrol- and Cardanol-Containing 1,3-Dioxolan-4-ones as Comonomers for the Synthesis of Functional Polylactide-Based Materials. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01537] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stefano Gazzotti
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
- CRC Materiali Polimerici “LaMPo”, Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
| | - Marco Aldo Ortenzi
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
- CRC Materiali Polimerici “LaMPo”, Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
| | - Hermes Farina
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
- CRC Materiali Polimerici “LaMPo”, Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
| | - Mariapina Disimino
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
- CRC Materiali Polimerici “LaMPo”, Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
| | - Alessandra Silvani
- Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
- CRC Materiali Polimerici “LaMPo”, Dipartimento di Chimica, Università degli Studi di Milano, Via Golgi 19, 20133 Milano, Italy
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9
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Bhattacharjee J, Harinath A, Sarkar A, Panda TK. Alkaline Earth Metal-Mediated Highly Iso-selective Ring-Opening Polymerization of rac-Lactide. Chem Asian J 2020; 15:860-866. [PMID: 32022475 DOI: 10.1002/asia.201901751] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/20/2020] [Indexed: 11/06/2022]
Abstract
Alkaline earth (Ae) metal complexes of the aminophosphine borane ligand are highly active and iso-selective catalysts for the ring-opening polymerization (ROP) of rac-lactide (LA). The polymerization reactions are well controlled and produce polylactides with molecular weights that are precise and narrowly distributed. Kinetic studies reveal that the ROP of rac-LA catalyzed by all Ae metal complexes had a first-order dependency on LA concentration as well as catalyst concentration. A plausible reaction mechanism for Ae metal complex-mediated ROP of rac-LA is discussed, based on controlled kinetic experiments and molecular chain mobility.
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Affiliation(s)
- Jayeeta Bhattacharjee
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi - 502285, Sangareddy, Telangana, India
| | - Adimulam Harinath
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi - 502285, Sangareddy, Telangana, India
| | - Alok Sarkar
- Momentive Performance Materials Pvt. Ltd., Bangalore, 560 100, India
| | - Tarun K Panda
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi - 502285, Sangareddy, Telangana, India
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10
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Hador R, Lipstman S, Rescigno R, Venditto V, Kol M. Aluminium complexes of salanol ligands: coordination chemistry and stereoselective lactide polymerization. Chem Commun (Camb) 2020; 56:13528-13531. [DOI: 10.1039/d0cc05957a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aluminium complexes of the new salanol ligands give rise to all PLA tacticities by different stereocontrol mechanisms.
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Affiliation(s)
- Rami Hador
- The School of Chemistry
- Tel Aviv University
- Ramat Aviv
- Israel
| | | | - Raffaella Rescigno
- Department of Chemistry and Biology A. Zambelli
- and INSTM Research Unit
- University of Salerno
- 84084 Fisciano
- Italy
| | - Vincenzo Venditto
- Department of Chemistry and Biology A. Zambelli
- and INSTM Research Unit
- University of Salerno
- 84084 Fisciano
- Italy
| | - Moshe Kol
- The School of Chemistry
- Tel Aviv University
- Ramat Aviv
- Israel
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11
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Fuchs M, Schmitz S, Schäfer PM, Secker T, Metz A, Ksiazkiewicz AN, Pich A, Kögerler P, Monakhov KY, Herres-Pawlis S. Mononuclear zinc(II) Schiff base complexes as catalysts for the ring-opening polymerization of lactide. Eur Polym J 2020. [DOI: 10.1016/j.eurpolymj.2019.109302] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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12
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Wei Y, Song L, Jiang L, Huang Z, Wang S, Yuan Q, Mu X, Zhu X, Zhou S. Aluminum complexes with Schiff base bridged bis(indolyl) ligands: synthesis, structure, and catalytic activity for polymerization of rac-lactide. Dalton Trans 2019; 48:15290-15299. [PMID: 31580352 DOI: 10.1039/c9dt02724f] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A series of Schiff base bridged bis(indolyl) ligands were developed for aluminum chemistry. The reactions of AlEt3 or AlMe3 with the Schiff base bridged bis(indolyl) proligands R1(-N[double bond, length as m-dash]CHC8H5NH)2 (R1 = -CH2CH2- (H2L1); -CH2CH2CH2- (H2L2); -CH2CMe2CH2- (H2L3); rac-Cy (H2L4); and R,R-Cy (H2L5)) were studied leading to the synthesis of a series of aluminum alkyl complexes L1AlEt (1)-L5AlEt (5) and L3AlMe (3b) in good yields, while the reaction of H2L3 with Al(OiPr)3 gave the aluminum alkoxide complex L3AlOiPr (3a). These aluminum complexes were characterized by spectroscopic methods and elemental analyses. The solid state structures of the aluminum complexes 1-5 and 3a were confirmed by the X-ray diffraction study. X-ray analyses revealed that the aluminum centre in these complexes is five-coordinated. The coordination geometry is between square pyramidal and trigonal bipyramidal. In the presence of 1 equiv. of isopropanol, the aluminum alkyl complexes exhibited notable activity towards the ring-opening polymerization of rac-lactide at 70 °C in toluene, with good control over molecular weights and dispersities. The substituents and the length of the bridging part between the two Schiff base nitrogen atoms have an influence on either the tacticity of isolated polymers or the rate of polymerization. The kinetics of complex L3AlOiPr (3a) in C6D6 was also investigated, and the experimental results revealed that the rate of polymerization was first-order with respect to rac-lactide.
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Affiliation(s)
- Yun Wei
- Laboratory of Functionalized Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, School of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, P. R. China.
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13
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Mechanistic Insight into the Ring-Opening Polymerization of ε-Caprolactone and L-Lactide Using Ketiminate-Ligated Aluminum Catalysts. Polymers (Basel) 2019; 11:polym11091530. [PMID: 31546919 PMCID: PMC6780811 DOI: 10.3390/polym11091530] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/11/2019] [Accepted: 09/17/2019] [Indexed: 11/17/2022] Open
Abstract
The reactivity and the reaction conditions of the ring-opening polymerization of ε-caprolactone (ε-CL) and L-lactide (LA) initiated by aluminum ketiminate complexes have been shown differently. Herein, we account for the observation by studying the mechanisms on the basis of density functional theory (DFT) calculations. The calculations show that the ring-opening polymerization of ε-CL and LA are rate-determined by the benzoxide insertion and the C–O bond cleavage step, respectively. Theoretical computations suggest that the reaction temperature of L–LA polymerization should be higher than that of ε-CL one, in agreement with the experimental data. To provide a reasonable interpretation of the experimental results and to give an insight into the catalyst design, the influence of the electronic, steric, and thermal effects on the polymerization behaviors will be also discussed in this study.
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14
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Wei C, Han B, Zheng D, Zheng Q, Liu S, Li Z. Aluminum Complexes Bearing Bidentate Amido–Phosphine Ligands for Ring-Opening Polymerization of ε-Caprolactone: Steric Effect on Coordination Chemistry and Reactivity. Organometallics 2019. [DOI: 10.1021/acs.organomet.9b00502] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Chuanzhi Wei
- Key Laboratory of Biobased Polymer Materials, Shandong Provincial Education Department; College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, People’s Republic of China
| | - Binghao Han
- Key Laboratory of Biobased Polymer Materials, Shandong Provincial Education Department; College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, People’s Republic of China
| | - Dejuan Zheng
- Key Laboratory of Biobased Polymer Materials, Shandong Provincial Education Department; College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, People’s Republic of China
| | - Quande Zheng
- Key Laboratory of Biobased Polymer Materials, Shandong Provincial Education Department; College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, People’s Republic of China
| | - Shaofeng Liu
- Key Laboratory of Biobased Polymer Materials, Shandong Provincial Education Department; College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, People’s Republic of China
| | - Zhibo Li
- Key Laboratory of Biobased Polymer Materials, Shandong Provincial Education Department; College of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, People’s Republic of China
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15
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Stewart JA, McKeown P, Driscoll OJ, Mahon MF, Ward BD, Jones MD. Tuning the Thiolen: Al(III) and Fe(III) Thiolen Complexes for the Isoselective ROP of rac-Lactide. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01205] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Jack A. Stewart
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Paul McKeown
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Oliver J. Driscoll
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Mary F. Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Benjamin D. Ward
- Department of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, U.K
| | - Matthew D. Jones
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
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16
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Salalens and Salans Derived from 3‐Aminopyrrolidine: Aluminium Complexation and Lactide Polymerisation. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900417] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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17
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18
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Lu WY, Chang YC, Lian CJ, Wu KH, Chiang MY, Chen HY, Lin CC, Ko BT. Optimization of six-membered ring aluminum complexes in ε-caprolactone polymerization. Eur Polym J 2019. [DOI: 10.1016/j.eurpolymj.2019.02.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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19
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Hu Q, Jie S, Braunstein P, Li BG. Highly active tridentate amino-phenol zinc complexes for the catalytic ring-opening polymerization of ε-caprolactone. J Organomet Chem 2019. [DOI: 10.1016/j.jorganchem.2018.12.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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20
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Beament J, Wolf T, Markwart JC, Wurm FR, Jones MD, Buchard A. Copolymerization of Cyclic Phosphonate and Lactide: Synthetic Strategies toward Control of Amphiphilic Microstructure. Macromolecules 2019. [DOI: 10.1021/acs.macromol.8b02385] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- James Beament
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U. K
| | - Thomas Wolf
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
| | - Jens C. Markwart
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
| | - Frederik R. Wurm
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany
| | - Matthew D. Jones
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U. K
| | - Antoine Buchard
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U. K
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21
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Li M, Behzadi S, Chen M, Pang W, Wang F, Tan C. Phenoxyimine Ligands Bearing Nitrogen-Containing Second Coordination Spheres for Zinc Catalyzed Stereoselective Ring-Opening Polymerization of rac-Lactide. Organometallics 2019. [DOI: 10.1021/acs.organomet.8b00788] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Min Li
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, People’s Republic of China
| | - Shabnam Behzadi
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, People’s Republic of China
| | - Min Chen
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, People’s Republic of China
| | - Wenmin Pang
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, People’s Republic of China
| | - Fuzhou Wang
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230026, People’s Republic of China
| | - Chen Tan
- Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, People’s Republic of China
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22
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Gao J, Zhu D, Zhang W, Solan GA, Ma Y, Sun WH. Recent progress in the application of group 1, 2 & 13 metal complexes as catalysts for the ring opening polymerization of cyclic esters. Inorg Chem Front 2019. [DOI: 10.1039/c9qi00855a] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review focuses on recent developments concerned with the use of well-defined main group complexes as (pre-)catalysts for the ROP of cyclic esters to give aliphatic polyesters; factors influencing catalytic activity, selectivity and polymer properties are all discussed.
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Affiliation(s)
- Jiahao Gao
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing Institute of Fashion Technology
- Beijing 100029
| | - Dongzhi Zhu
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing Institute of Fashion Technology
- Beijing 100029
| | - Wenjuan Zhang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment
- Beijing Engineering Research Center of Textile Nanofiber
- School of Materials Science and Engineering
- Beijing Institute of Fashion Technology
- Beijing 100029
| | - Gregory A. Solan
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
- China
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23
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Qin L, Zhang Y, Chao J, Cheng J, Chen X. Four- and five-coordinate aluminum complexes supported by N,O-bidentate β-pyrazylenolate ligands: synthesis, structure and application in ROP of ε-caprolactone and lactide. Dalton Trans 2019; 48:12315-12325. [DOI: 10.1039/c9dt02330e] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Two series of alkyl aluminum complexes LAlMe2 and L2AlMe supported by N,O-bidentate β-pyrazylenolate ligands have been synthesized and applied to the ROP of ε-CL and rac-LA.
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Affiliation(s)
- Lu Qin
- School of Chemistry and Chemical Engineering
- Shanxi University
- Taiyuan
- China
| | - Yue Zhang
- School of Chemistry and Chemical Engineering
- Shanxi University
- Taiyuan
- China
| | - Jianbin Chao
- Scientific Instrument Center
- Shanxi University
- Taiyuan
- China
| | - Jianhua Cheng
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Science
- Changchun
- China
| | - Xia Chen
- School of Chemistry and Chemical Engineering
- Shanxi University
- Taiyuan
- China
- State Key Laboratory of Polymer Physics and Chemistry
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24
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Kuchuk E, Muratov K, Perekalin DS, Chusov D. Anthracene-rhodium complexes with metal coordination at the central ring - a new class of catalysts for reductive amination. Org Biomol Chem 2018; 17:83-87. [PMID: 30520492 DOI: 10.1039/c8ob02561d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A new class of anthracene complexes with a metal coordinated at the central ring was applied in catalysis for the first time. As a result, a simple and efficient protocol for reductive amination that involves CO as a reducing agent has been developed. The rhodium complex [(cyclooctadiene)Rh(C10H4Me2(OMe)4)]+ (1 mol%) catalyses such reactions under mild conditions (40-130 °C) and produces a variety of amines in good yields (74-95%) without affecting the functional groups. The protocol is acceptable for all combinations of aldehydes (aromatic and aliphatic), ketones (aromatic and aliphatic) and amines (aromatic and aliphatic; primary and secondary).
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Affiliation(s)
- Ekaterina Kuchuk
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow 119991, Russia.
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