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Buchard A, Chuck CJ, Davidson MG, Gobius du Sart G, Jones MD, McCormick SN, Russell AD. A Highly Active and Selective Zirconium-Based Catalyst System for the Industrial Production of Poly(lactic acid). ACS Catal 2023; 13:2681-2695. [PMID: 36846823 PMCID: PMC9942235 DOI: 10.1021/acscatal.2c05690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 01/20/2023] [Indexed: 02/10/2023]
Abstract
The biodegradable, aliphatic polyester poly(lactic acid), PLA, is a leading bio-based alternative to petrochemical-derived plastic materials across a range of applications. Widely reported in the available literature as a benchmark for PLA production via the bulk ring-opening polymerization of lactides is the use of divalent tin catalysts, and particularly tin(II) bis(2-ethylhexanoate). We present an alternative zirconium-based system that combines an inexpensive Group IV metal with the robustness, high activity, control, and designed compatibility with existing facilities and processes, that are required for industrial use. We have carried out a comprehensive kinetic study and applied a combined experimental and theoretical approach to understanding the mechanism by which the polymerization of lactide proceeds in the presence of this system. In the laboratory-scale (20 g) polymerization of recrystallized racemic d,l-lactide (rac-lactide), we have measured catalyst turnover frequencies up to at least 56,000 h-1, and confirmed the reported protocols' resistance toward undesirable epimerization, transesterification, and chain scission processes, deleterious to the properties of the polymer product. Further optimization and scale-up under industrial conditions have confirmed the relevance of the catalytic protocol to the commercial production of melt-polymerized PLA. We were able to undertake the efficient preparation of high-molecular-weight PLA on the 500-2000 g scale, via the selective and well-controlled polymerization of commercial polymer-grade l-lactide under challenging, industrially relevant conditions, and at metal concentrations as low as 8-12 ppm Zr by weight ([Zr] = 1.3 × 10-3 to 1.9 × 10-3 mol %). Under those conditions, a catalyst turnover number of at least 60,000 was attained, and the activity of the catalyst was comparable to that of tin(II) bis(2-ethylhexanoate).
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Affiliation(s)
- Antoine Buchard
- Institute
for Sustainability, University of Bath, BathBA2 7AY, U.K.,Department
of Chemistry, University of Bath, BathBA2 7AY, U.K.
| | - Christopher J. Chuck
- Institute
for Sustainability, University of Bath, BathBA2 7AY, U.K.,Department
of Chemical Engineering, University of Bath, BathBA2 7AY, U.K.
| | - Matthew G. Davidson
- Institute
for Sustainability, University of Bath, BathBA2 7AY, U.K.,Department
of Chemistry, University of Bath, BathBA2 7AY, U.K.,
| | | | - Matthew D Jones
- Institute
for Sustainability, University of Bath, BathBA2 7AY, U.K.,Department
of Chemistry, University of Bath, BathBA2 7AY, U.K.
| | - Strachan N. McCormick
- Institute
for Sustainability, University of Bath, BathBA2 7AY, U.K.,Department
of Chemistry, University of Bath, BathBA2 7AY, U.K.,
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2
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Duan YL, Guo Q, Liu G, Yi Z, Feng S, Huang Y. Highly heteroselective ring-opening polymerization of rac-lactide initiated by rare-earth alkoxides bearing chiral [NNOO]-type amine-bis(phenolate) ligands. Polym Chem 2022. [DOI: 10.1039/d2py00455k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of new monomeric rare-earth alkoxides (1-6) were successfully synthesized by one-pot reaction of chiral [NNOO]-type amine-bridged bis(phenolate) ligands ((S)-L1-4-H2), Ln[N(SiMe3)2]3 (Ln = Y, Sm, Nd) and 2-propanol in...
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3
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Hu M, Song X, Wang F, Zhang W, Ma W, Han F. Ring-opening polymerization of rac-lactide catalyzed by magnesium and zinc complexes supported by an NNO ligand. NEW J CHEM 2022. [DOI: 10.1039/d1nj05157a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Preparation of magnesium and zinc complexes containing unsymmetric tertiary amine ligands and their catalytic properties for polymerization of rac-lactide.
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Affiliation(s)
- Minggang Hu
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
- Heilongjiang Provincial Key Laboratory of Catalytic Synthesis for Fine Chemicals, Qiqihar University, Qiqihar, 161006, China
| | - Xinfeng Song
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Fugui Wang
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Wenzhi Zhang
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Wenhui Ma
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Fuzhong Han
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
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4
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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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5
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Polymetallic Group 4 Complexes: Catalysts for the Ring Opening Polymerisation of rac-Lactide. Catalysts 2021. [DOI: 10.3390/catal11050551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Five novel air- and moisture-stable polymetallic Ti and Zr amino acid-derived amine bis(phenolate) (ABP) complexes were synthesised and fully characterised, including X-ray crystallographic studies. The reaction of the ABP proligands with Ti or Zr alkoxides has resulted in the formation of polymetallic aggregates of different nuclearity. The steric bulk on the pendant arm of the ligand was found to play a critical role in establishing the nuclearity of the aggregated complex. Sterically, less-demanding groups, such as H or Me, facilitated the formation of tetrametallic Ti clusters, bridged by carboxylate groups, while increased steric bulk (tBu) led to the formation of binuclear μ-oxo-bridged species. The isolated complexes were employed as catalysts for the ring opening polymerisation (ROP) of rac-lactide. Overall, the Ti catalysts were all active with the smaller, bimetallic Ti aggregates exhibiting relatively faster rates. A monometallic, bis(ABP) Zr complex was found to exert remarkable ROP activity, albeit with limited control over the tacticity and molecular weight distribution of the polymer. A further oxo-bridged Zr cluster was shown to display a previously unprecedented trimetallic structure and achieved a moderate rate in the ROP of rac-lactide.
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Roymuhury SK, Mandal M, Chakraborty D, Ramkumar V. Homoleptic titanium and zirconium complexes exhibiting unusual Oiminol–metal coordination: application in stereoselective ring-opening polymerization of lactide. Polym Chem 2021. [DOI: 10.1039/d1py00237f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The synthesis and characterization of novel homoleptic Ti and Zr complexes with tridentate ONO-type Schiff base ligands and their catalytic activities towards the ring-opening polymerization (ROP) of lactide are reported.
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Affiliation(s)
- Sagnik K. Roymuhury
- Department of Chemistry
- Indian Institute of Technology Patna
- Bihta 801103
- India
| | - Mrinmay Mandal
- Department of Chemistry
- Indian Institute of Technology Patna
- Bihta 801103
- India
| | - Debashis Chakraborty
- Department of Chemistry
- Indian Institute of Technology Madras
- Chennai-600 036
- India
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7
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Choe S, Lee H, Nayab S. Synthesis, structures, and catalytic efficiency in ring opening polymerization of rac-lactide with tridentate vs. bidentate cobalt( ii), zinc( ii), and cadmium( ii) complexes containing N-substituted N, N-bis((3,5-dimethyl-1 H-pyrazol-1-yl)methyl)amine ligands. RSC Adv 2021; 11:18840-18851. [PMID: 35478641 PMCID: PMC9033469 DOI: 10.1039/d1ra02365a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 05/20/2021] [Indexed: 01/09/2023] Open
Abstract
A series of Co(ii), Zn(ii), and Cd(ii) complexes supported by 1-(3,5-dimethyl-1H-pyrazol-1-yl)-N-((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-N-(furan-2-ylmethyl)methanamine (LA) and N,N-bis((3,5-dimethyl-1H-pyrazol-1-yl)methyl)-4-isopropylaniline (LB) were synthesized. The direct chelation of CoCl2·6H2O, ZnCl2, and CdBr2·4H2O by the ligands produced [LnMX2] (Ln = LA or LB; M = Zn or Co, with X = Cl; M = Cd, with X = Br) complexes in high yields. Structural studies revealed that [LBCoCl2] and [LBZnCl2] adopted distorted tetrahedral geometries, as LB coordinated the metal centers in a bidentate fashion, while LA coordinated the metal centers in a tridentate fashion through the nitrogen atoms of the pyrazole and amine moieties, so that [LACoCl2] and [LAZnCl2] exhibited trigonal bipyramidal geometries and [LACdBr2] a square pyramidal geometry. [LBCdBr2] has two Cd-containing structures per unit cell, whereby one Cd center adopted a distorted tetrahedral geometry and the other exhibited square bipyramidal geometry. The in situ-generated alkyl derivatives of the synthesized complexes were assessed in the ring-opening polymerization of rac-lactide. Heterotactic polylactides (PLAs) were furnished with all complexes. The [LBZnCl2]/MeLi system produced PLA with a superior heterotactic bias (Pr up to 0.94) at −25 °C. PLAs with wide-ranging polydispersity indices (1.16–2.23) and low molecular weights were produced in all cases, irrespective of the specific M(II) center and ancillary ligand utilized. Co(ii), Zn(ii), and Cd(ii) complexes supported by bis-pyrazolyl ligands were applied to the ring-opening polymerization of rac-lactide to produce heterotactic polylactides (PLAs) with superior heterotactic bias i.e. Pr up to 0.94 at −25 °C.![]()
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Affiliation(s)
- Solhye Choe
- Department of Chemistry and Green-Nano Materials Research Center
- Kyungpook National University
- Daegu
- Republic of Korea
| | - Hyosun Lee
- Department of Chemistry and Green-Nano Materials Research Center
- Kyungpook National University
- Daegu
- Republic of Korea
| | - Saira Nayab
- Department of Chemistry
- Shaheed Benazir Bhutto University
- Islamic Republic of Pakistan
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8
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Khononov M, Liu H, Fridman N, Tamm M, Eisen MS. Benzimidazolin-2-iminato Hafnium Complexes: Synthesis, Characterization, and Catalytic Addition of Alcohols to Carbodiimides. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00384] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Maxim Khononov
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City 32000, Israel
| | - Heng Liu
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City 32000, Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City 32000, Israel
| | - Matthias Tamm
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Moris S. Eisen
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City 32000, Israel
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9
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Khononov M, Fridman N, Tamm M, Eisen MS. Hydroboration of Aldehydes, Ketones, and Carbodiimides Promoted by Mono(imidazolin‐2‐iminato) Hafnium Complexes. European J Org Chem 2020. [DOI: 10.1002/ejoc.201901750] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Maxim Khononov
- Schulich Faculty of Chemistry TechnionIsrael Institute of Technology 32000 Haifa City Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry TechnionIsrael Institute of Technology 32000 Haifa City Israel
| | - Matthias Tamm
- Institut fürAnorganische und Analytische Chemie Technische Universität Braunschweig Hagenring 30 38106 Braunschweig Germany
| | - Moris S. Eisen
- Schulich Faculty of Chemistry TechnionIsrael Institute of Technology 32000 Haifa City Israel
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10
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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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11
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Li X, Jia Z, Pan X, Wu J. Isoselective Ring-Opening Polymerization of rac-Lactide Catalyzed by Sodium/potassium Tetradentate Aminobisphenolate Ion-paired Complexes. Chem Asian J 2019; 14:662-669. [PMID: 30644176 DOI: 10.1002/asia.201801834] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/14/2019] [Indexed: 02/04/2023]
Abstract
Two sodium/potassium tetradentate aminobisphenolate ion-paired complexes were synthesized and structurally characterized. These ion-paired complexes are efficient catalysts for the ring-opening polymerization of rac-lactide (rac-LA) in the presence of 5 equivalents BnOH as an initiator and the side reaction of epimerization can be suppressed well at low temperatures. The polymerizations are controllable, affording polylactides with desirable molecular weights and narrow molecular weight distributions; the highest molecular weight can reach 50.1 kg mol-1 in this system, and a best isoselectivity of Pm =0.82 was achieved. Such polymerizations have rarely been reported for isoselective sodium/potassium complexes without crown ether as an auxiliary ligand. The solid structures suggest that BnOH can be activated by an interaction with the anion of sodium/potassium complex via a hydrogen bond and that the monomer is activated by coordination to sodium/potassium ion.
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Affiliation(s)
- Xinlei Li
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University, Lanzhou, 730000, P. R. China
| | - Zhaowei Jia
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University, Lanzhou, 730000, P. R. China
| | - Xiaobo Pan
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University, Lanzhou, 730000, P. R. China
| | - Jincai Wu
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou University, Lanzhou, 730000, P. R. China
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12
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Gong Y, Ma H. High performance benzoimidazolyl-based aminophenolate zinc complexes for isoselective polymerization of rac-lactide. Chem Commun (Camb) 2019; 55:10112-10115. [PMID: 31384844 DOI: 10.1039/c9cc04834k] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Zinc complexes supported by achiral benzoimidazolyl-based aminophenolate ligands exhibit high catalytic activities and excellent isoselectivities toward the ring-opening polymerization of rac-lactide under mild conditions.
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Affiliation(s)
- Yanmei Gong
- Shanghai Key Laboratory of Functional Materials Chemistry and Laboratory of Organometallic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, P. R. China.
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13
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Mandal M, Ramkumar V, Chakraborty D. Salen complexes of zirconium and hafnium: synthesis, structural characterization and polymerization studies. Polym Chem 2019. [DOI: 10.1039/c8py01750f] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Salen complexes of zirconium and hafnium were synthesized and used as effective catalysts for the polymerization of lactide and ε-CL and homopolymerization, copolymerization and coupling of epoxides with CO2.
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Affiliation(s)
- Mrinmay Mandal
- Department of Chemistry
- Indian Institute of Technology Patna
- Bihta 801103
- India
| | | | - Debashis Chakraborty
- Department of Chemistry
- Indian Institute of Technology Madras
- Chennai-600 036
- India
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14
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Group 4 metal complexes containing the salalen ligands: Synthesis, structural characterization and studies on the ROP of cyclic esters. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2018.03.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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15
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Hu M, Zhang W, Ma W, Han F, Song W. Preparation of titanium complexes containing unsymmetric N2O2-ligands and their catalytic properties for polymerization of rac-lactide. POLYMER 2018. [DOI: 10.1016/j.polymer.2018.08.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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16
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Beament J, Mahon MF, Buchard A, Jones MD. Aluminum Complexes of Monopyrrolidine Ligands for the Controlled Ring-Opening Polymerization of Lactide. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00161] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- James Beament
- 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
| | - Antoine Buchard
- Department of Chemistry, University of Bath, Claverton
Down Bath BA2 7AY, U.K
| | - Matthew D. Jones
- Department of Chemistry, University of Bath, Claverton
Down Bath BA2 7AY, U.K
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17
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Huang Y, Kou X, Duan YL, Ding FF, Yin YF, Wang W, Yang Y. Magnesium and zinc complexes bearing NNO-tridentate ketiminate ligands: synthesis, structures and catalysis in the ring-opening polymerization of lactides. Dalton Trans 2018; 47:8121-8133. [DOI: 10.1039/c8dt00888d] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Magnesium and zinc complexes bearing pyrazoline-derived ketiminate ligands, [(L1–3)2M2(μ-OBn)2] and [M(L)2] proceed through the “coordination–insertion” mechanism in the ROP of lactides.
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Affiliation(s)
- Yong Huang
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Xin Kou
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Yu-Lai Duan
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Fei-Fei Ding
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Yi-Fan Yin
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Wei Wang
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Ying Yang
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
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18
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Synthesis of Li(I), Zn(II) and Mg(II) complexes of amine bis(phenolates) and their exploitation for the ring opening polymerisation of rac-lactide. J Organomet Chem 2017. [DOI: 10.1016/j.jorganchem.2017.08.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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19
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Rajashekhar B, Mandal M, Chakraborty D, Ramkumar V. Homoleptic Zr and Hf Complexes of Imino/Bis(imino)phenoxide Scaffolds: Synthesis, Structural Characterization and Their Catalytic Activity in the ROP of Cyclic Esters. ChemistrySelect 2017. [DOI: 10.1002/slct.201701602] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Bijja Rajashekhar
- Department of Chemistry; Indian Institute of Technology Madras; Chennai- 600 036, Tamil Nadu India
| | - Mrinmay Mandal
- Department of Chemistry; Indian Institute of Technology Patna; Bihta 801103, Bihar India
| | - Debashis Chakraborty
- Department of Chemistry; Indian Institute of Technology Madras; Chennai- 600 036, Tamil Nadu India
| | - Venkatachalam Ramkumar
- Department of Chemistry; Indian Institute of Technology Madras; Chennai- 600 036, Tamil Nadu India
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