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Mankaev BN, Karlov SS. Metal Complexes in the Synthesis of Biodegradable Polymers: Achievements and Prospects. MATERIALS (BASEL, SWITZERLAND) 2023; 16:6682. [PMID: 37895663 PMCID: PMC10608263 DOI: 10.3390/ma16206682] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/05/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023]
Abstract
This review describes recent advances in the synthesis of homopolymers of lactide and related cyclic esters via ring-opening polymerization (ROP) in the presence of metal complexes based on group 1, 2, 4, 12, 13 and 14 metals. Particular attention is paid to the influence of the initiator structure on the properties of the obtaining homo- and copolymers. Also, a separate chapter is devoted to the study of metal complexes in the synthesis of copolymers of lactide and lactones. This review highlights the efforts made over the last ten years or so, and shows how main-group metals have received increasing attention in the field of the polymerization of lactide and related cyclic esters.
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Affiliation(s)
- Badma N. Mankaev
- Chemistry Department, Lomonosov Moscow State University, 119991 Moscow, Russia;
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Science, 119991 Moscow, Russia
| | - Sergey S. Karlov
- Chemistry Department, Lomonosov Moscow State University, 119991 Moscow, Russia;
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Science, 119991 Moscow, Russia
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2
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Nakornkhet C, Nanok T, Wattanathana W, Chuawong P, Hormnirun P. Titanium Complexes of Salicylbenzoxazole and Salicylbenzothiazole Ligands for the Ring-Opening Polymerization of ε-Caprolactone and Substituted ε-Caprolactones and Their Copolymerizations. Inorg Chem 2022; 61:7945-7963. [PMID: 35537466 DOI: 10.1021/acs.inorgchem.2c00577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two series of titanium complexes, including salicylbenzoxazole titanium complexes (1-4) and salicylbenzothiazole titanium complexes (5-8), were successfully synthesized and characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction crystallography (for 2 and 5). The 1H NMR spectra of complexes 7 and 8 reveal fluxional behavior in solution at room temperature, and the activation parameters were determined by lineshape analysis of variable-temperature (VT) NMR spectra in toluene-d8: for 7, ΔH⧧ = 73.0 ± 1.8 kJ mol-1, ΔS⧧ = 22.1 ± 5.5 J mol-1 K-1; for 8, ΔH⧧ = 73.7 ± 1.2 kJ mol-1, ΔS⧧ = 20.3 ± 3.8 J mol-1 K-1. The positive values of ΔS⧧ suggested that the isomerization occurred via a dissociative mechanism. All complexes were active initiators for the ring-opening polymerization of ε-caprolactone (ε-CL) and three substituted ε-CLs: γ-methyl-ε-caprolactone (γMeCL), γ-ethyl-ε-caprolactone (γEtCL), and γ-phenyl-ε-caprolactone (γPhCL). Of all complexes, complex 5 was found to be the most active initiator in this study. The copolymerizations between ε-CL and three substituted ε-CLs produced completely random copolymers. The polymerization was proposed to proceed via a dissociative coordination-insertion mechanism. The catalytic activity of the salicylbenzoxazole titanium complex was lower than that of its closely related salicylbenzothiazole titanium congener. Additionally, DFT calculations unveiled that the ligand decoordination step and the less steric congestion at the titanium center in the salicylbenzothiazole titanium complexes were the key factors in enhancing the catalytic rate.
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Affiliation(s)
- Chutikan Nakornkhet
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Tanin Nanok
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.,Center 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
| | - Pitak Chuawong
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Pimpa Hormnirun
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.,Center for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, Kasetsart University, Bangkok 10900, Thailand
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3
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Seo CCY, Ahmed M, Oliver AG, Durr CB. Titanium ONN-(phenolate) Alkoxide Complexes: Unique Reaction Kinetics for Ring-Opening Polymerization of Cyclic Esters. Inorg Chem 2021; 60:19336-19344. [PMID: 34871501 DOI: 10.1021/acs.inorgchem.1c03157] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis, characterization, and polymerization kinetics of four new titanium ONN-(phenolate) alkoxide catalysts were studied. Each catalyst is fluxional at room temperature, suggesting the ligand amine arm may be labile, but adopts a fac geometry in solution at low temperature (223 K) and in the solid state. All catalysts are active for the ring-opening polymerization of both ε-caprolactone (CL) and rac-lactide (LA). GPC analysis indicates that the well-known coordination-insertion mechanism is being followed. However, whereas the typical first-order dependence on monomer concentration is observed in CL, an unexpected zeroth-order dependence is observed with LA. This suggests that, in the case of LA, catalyst saturation occurs and a Michaelis-Menten model can be used to explain the kinetics. An initial mechanism is discussed within this model that proposes CL polymerization proceeds by a 7-coordinate intermediate, whereas LA polymerization adopts a 6-coordinate intermediate, facilitated by the ligand amine arm. Attempts to isolate catalyst-monomer intermediates are ongoing.
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Affiliation(s)
- Clara C Y Seo
- Department of Chemistry, Amherst College, 25 East Drive, Amherst, Massachusetts 01002, United States
| | - Mayesha Ahmed
- Department of Chemistry, Amherst College, 25 East Drive, Amherst, Massachusetts 01002, United States
| | - Allen G Oliver
- Department of Chemistry and Biochemistry, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, Indiana 46556, United States
| | - Christopher B Durr
- Department of Chemistry, Amherst College, 25 East Drive, Amherst, Massachusetts 01002, United States
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Upitak K, Wattanathana W, Nanok T, Chuawong P, Hormnirun P. Titanium complexes of pyrrolylaldiminate ligands and their exploitation for the ring-opening polymerization of cyclic esters. Dalton Trans 2021; 50:10964-10981. [PMID: 34318841 DOI: 10.1039/d1dt01470f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A series of six-coordinate titanium complexes 1-6 supported by pyrrolylaldiminate ligands were prepared via the reaction of 2 equivalents of ligands and Ti(OiPr)4 in toluene at 70 °C. The X-ray structure of 2 revealed that the two ligands were κ2-coordinated to the titanium center with the two pyrrole nitrogen atoms in trans positions and the two imine nitrogen atoms in cis positions. All complexes were active initiators for the ring-opening polymerization (ROP) of rac-lactide (rac-LA), ε-caprolactone (ε-CL), and three substituted ε-caprolactones (γ-methyl-ε-caprolactone (γMeCL), γ-ethyl-ε-caprolactone (γEtCL), and γ-phenyl-ε-caprolactone (γPhCL)). Polymerizations of all monomers were well controlled, affording predetermined molar masses and narrow dispersity values. Complex 5 exhibited the highest polymerization activities with rac-LA and ε-CL and its performance was comparable to other highly active six-coordinate titanium complexes reported thus far. Kinetic results revealed a first-order dependency on the monomer concentration, and the rate of polymerization was greatly influenced by the substituent on the imine nitrogen. End-group analysis of the isolated PLA and PCL suggested a coordination-insertion mechanism.
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Affiliation(s)
- Kanokon Upitak
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
| | - Worawat Wattanathana
- Department of Materials Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900, Thailand
| | - Tanin Nanok
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
| | - Pitak Chuawong
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
| | - Pimpa Hormnirun
- Laboratory of Catalysts and Advanced Polymer Materials, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.
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5
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Durr CB, Williams CK. New Coordination Modes for Modified Schiff Base Ti(IV) Complexes and Their Control over Lactone Ring-Opening Polymerization Activity. Inorg Chem 2018; 57:14240-14248. [PMID: 30376308 DOI: 10.1021/acs.inorgchem.8b02271] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A series of eight new bis(alkoxy)bis(phenoxy-imine)titanium(IV) catalysts, coordinated by Schiff base ligands derived from o-vanillin (2-hydroxy-3-methoxybenzaldehyde), show good activity and control for the ring-opening polymerization of ε-caprolactone and ω-pentadecalactone. The new complexes are easily prepared in two high-yield steps from commercial reagents. The new ligands can all adopt two different coordination modes, depending on the steric bulk on the imine: a six-membered N-O chelate and/or a five-membered O-O chelate. The complexes show three different structures, depending on the ligand coordination mode: type A (N-O:N-O), type B (N-O:O-O), and type C (O-O:O-O). In all cases, the structures were confirmed in solution using variable temperature NMR spectroscopy and in the solid state using X-ray crystallography. The complex structure influences the polymerization rate, with the catalytic activities decreasing in the order: type C > type B > type A for both monomers. Overall, the work demonstrates potential to use these new ligands to access particular coordination modes, which allows enhancement of catalytic activity.
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Affiliation(s)
- Christopher B Durr
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , 12 Mansfield Road , Oxford OX1 3TA , United Kingdom
| | - Charlotte K Williams
- Chemistry Research Laboratory, Department of Chemistry , University of Oxford , 12 Mansfield Road , Oxford OX1 3TA , United Kingdom
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Ou HW, Lu WY, Vandavasi JK, Lin YF, Chen HY, Lin CC. Improvement in titanium complexes supported by Schiff bases in ring-opening polymerization of cyclic esters: ONO-tridentate Schiff bases. POLYMER 2018. [DOI: 10.1016/j.polymer.2018.02.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Bhattacharjee J, Harinath A, Nayek HP, Sarkar A, Panda TK. Highly Active and Iso-Selective Catalysts for the Ring-Opening Polymerization of Cyclic Esters using Group 2 Metal Initiators. Chemistry 2017; 23:9319-9331. [DOI: 10.1002/chem.201700672] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Jayeeta Bhattacharjee
- Department of Chemistry; Indian Institute of Technology Hyderabad; Kandi 502 285, Sangareddy, Telangana India
| | - Adimulam Harinath
- Department of Chemistry; Indian Institute of Technology Hyderabad; Kandi 502 285, Sangareddy, Telangana India
| | - Hari Pada Nayek
- Department of Applied Chemistry; Indian Institute of Technology (ISM), Dhanbad; 826004 Jharkhand India
| | - Alok Sarkar
- Momentive Performance Materials Pvt. Ltd. Survey No. 09; Hosur Road Electronic City (West) Bangalore 560100 India
| | - Tarun K. Panda
- Department of Chemistry; Indian Institute of Technology Hyderabad; Kandi 502 285, Sangareddy, Telangana India
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Lee CL, Lin YF, Jiang MT, Lu WY, Vandavasi JK, Wang LF, Lai YC, Chiang MY, Chen HY. Improvement in Aluminum Complexes Bearing Schiff Bases in Ring-Opening Polymerization of ε-Caprolactone: A Five-Membered-Ring System. Organometallics 2017. [DOI: 10.1021/acs.organomet.7b00068] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Chieh-Ling Lee
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
| | - Ya-Fan Lin
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
- Department
of Fragrance and Cosmetic Science, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
| | - Man-Ting Jiang
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
| | - Wei-Yi Lu
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
| | | | - Li-Fang Wang
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
| | - Yi-Chun Lai
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
| | - Michael Y. Chiang
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
- Department
of Chemistry, National Sun Yat-sen University, Kaohsiung 80424, Taiwan, Republic of China
| | - Hsuan-Ying Chen
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan, Republic of China
- Department
of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan, Republic of China
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9
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Tseng HC, Chen HY, Huang YT, Lu WY, Chang YL, Chiang MY, Lai YC, Chen HY. Improvement in Titanium Complexes Bearing Schiff Base Ligands in the Ring-Opening Polymerization of L-Lactide: A Dinuclear System with Hydrazine-Bridging Schiff Base Ligands. Inorg Chem 2016; 55:1642-50. [DOI: 10.1021/acs.inorgchem.5b02590] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hsi-Ching Tseng
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan R.O.C
| | - Hsing-Yin Chen
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan R.O.C
| | - Yen-Tzu Huang
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan R.O.C
| | - Wei-Yi Lu
- Department
of Chemistry, National Chung Hsing University, Taichung 402, Taiwan R.O.C
| | - Yu-Lun Chang
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan R.O.C
- Department
of Chemistry, National Sun Yat-Sen University, Kaohsiung 804, Taiwan R.O.C
| | - Michael Y. Chiang
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan R.O.C
- Department
of Chemistry, National Sun Yat-Sen University, Kaohsiung 804, Taiwan R.O.C
| | - Yi-Chun Lai
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan R.O.C
| | - Hsuan-Ying Chen
- Department
of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan R.O.C
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10
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Bednarek M, Basko M, Biedron T, Wojtczak E, Michalski A. Polymerization of lactide initiated by primary amines and catalyzed by a protic acid. Eur Polym J 2015. [DOI: 10.1016/j.eurpolymj.2015.08.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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11
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Lapenta R, Mazzeo M, Grisi F. Monoamidinate titanium complexes: highly active catalysts for the polymerization and copolymerization of l-lactide and ε-caprolactone. RSC Adv 2015. [DOI: 10.1039/c5ra15599a] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
A series of titanium trichloroamidinate complexes with distinct ligand sets showed different abilities in the copolymerization of ε-caprolactone and l-lactide, producing copolymers ranging from gradient to truly random microstructures.
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Affiliation(s)
- Rosita Lapenta
- Department of Chemistry and Biology "Adolfo Zambelli"
- University of Salerno
- Salerno
- Italy
| | - Mina Mazzeo
- Department of Chemistry and Biology "Adolfo Zambelli"
- University of Salerno
- Salerno
- Italy
| | - Fabia Grisi
- Department of Chemistry and Biology "Adolfo Zambelli"
- University of Salerno
- Salerno
- Italy
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12
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Webster RL. Random copolymerisations catalysed by simple titanium α-amino acid complexes. RSC Adv 2014. [DOI: 10.1039/c3ra45810e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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