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Buchard A, Davidson MG, Gobius du Sart G, Jones MD, Kociok-Köhn G, McCormick SN, Mckeown P. Coordination of ε-Caprolactone to a Cationic Niobium(V) Alkoxide Complex: Fundamental Insight into Ring-Opening Polymerization via Coordination-Insertion. Inorg Chem 2023; 62:15688-15699. [PMID: 37695575 PMCID: PMC10523432 DOI: 10.1021/acs.inorgchem.3c02491] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Indexed: 09/12/2023]
Abstract
We report three niobium-based initiators for the catalytic ring-opening polymerization (ROP) of ε-caprolactone, exhibiting good activity and molecular weight control. In particular, we have prepared on the gram-scale and fully characterized a monometallic cationic alkoxo-Nb(V) ε-caprolactone adduct representing, to the best of our knowledge, an unprecedented example of a metal complex with an intact lactone monomer and a functional ROP-initiating group simultaneously coordinated at the metal center. At 80 °C, all three systems initiate the immortal solution-state ROP of ε-caprolactone via a coordination-insertion mechanism, which has been confirmed through experimental studies, and is supported by computational data. Natural bond orbital calculations further indicate that polymerization may necessitate isomerization about the metal center between the alkoxide chain and the coordinated monomer. The observations made in this work are expected to inform mechanistic understanding both of amine tris(phenolate)-supported metal alkoxide ROP initiators, including various highly stereoselective systems for the polymerization of lactides and of coordination-insertion-type ROP protocols more broadly.
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Affiliation(s)
- Antoine Buchard
- Institute
for Sustainability, University of Bath, Bath BA2 7AY, U.K.
- Department
of Chemistry, University of Bath, Bath BA2 7AY, U.K.
| | - Matthew G. Davidson
- Institute
for Sustainability, University of Bath, Bath BA2 7AY, U.K.
- Department
of Chemistry, University of Bath, Bath BA2 7AY, U.K.
| | | | - Matthew D. Jones
- Institute
for Sustainability, University of Bath, Bath BA2 7AY, U.K.
- Department
of Chemistry, University of Bath, Bath BA2 7AY, U.K.
| | - Gabriele Kociok-Köhn
- Material
and Chemical Characterization and Analysis Facility (MC2), University of Bath, Bath BA2 7AY, U.K.
| | - Strachan N. McCormick
- Institute
for Sustainability, University of Bath, Bath BA2 7AY, U.K.
- Department
of Chemistry, University of Bath, Bath BA2 7AY, U.K.
| | - Paul Mckeown
- Department
of Chemistry, University of Bath, Bath BA2 7AY, U.K.
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2
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Tsarevsky NV. Special Issue: Functional Polymers and Composites: From Synthesis to Applications (Dedicated to the 80th Anniversary of Professor George S. Georgiev). POLYM INT 2022. [DOI: 10.1002/pi.6425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Nicolay V. Tsarevsky
- Department of Chemistry Southern Methodist University 3215 Daniel Avenue Dallas Texas 75275 USA
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3
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Gümüştaş S, Balcan M, Kinal A. Investigation of initiator metal efficiency in the ring‐opening polymerization of lactones: an experimental and computational study. POLYM INT 2022. [DOI: 10.1002/pi.6361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sıla Gümüştaş
- Chemistry Department, Faculty of Science Ege University Izmir Turkey
| | - Mehmet Balcan
- Chemistry Department, Faculty of Science Ege University Izmir Turkey
| | - Armağan Kinal
- Chemistry Department, Faculty of Science Ege University Izmir Turkey
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4
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Gaston AJ, Greindl Z, Morrison CA, Garden JA. Cooperative Heterometallic Catalysts for Lactide Ring-Opening Polymerization: Combining Aluminum with Divalent Metals. Inorg Chem 2021; 60:2294-2303. [PMID: 33512999 DOI: 10.1021/acs.inorgchem.0c03145] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
While homometallic (salen)Al catalysts display excellent performance in lactide ring-opening polymerization (ROP), heterometallic (salen)Al complexes have yet to be reported. Herein, we describe four heterobimetallic (salen)Al catalysts and show that the choice of the heterometal is key. Cooperative Al/Mg and Al/Zn combinations improved the catalyst activity by a factor of up to 11 compared to the mono-Al analogue, whereas the mono-Mg and mono-Zn analogues were completely inactive. In contrast, Al/Li and Al/Ca heterocombinations stunted the polymerization rate. Kinetic and computational studies suggest that Al/Mg and Al/Zn cooperativity arises from the close intermetallic proximity facilitating chloride bridging (thus enhancing initiation), which promotes a rigid square pyramidal geometry around the Al center and further increases the available monomer coordination sites. This work also translates the use of ab initio molecular dynamics calculations to ROP, introducing a useful method of investigating catalyst flexibility and revealing that ligand strain and molecular rigidity can enhance heterometallic catalyst performance.
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Affiliation(s)
- Anand J Gaston
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - Zoe Greindl
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - Carole A Morrison
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
| | - Jennifer A Garden
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, U.K
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5
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Jitonnom J, Meelua W. DFT study of lactide ring-opening polymerizations by aluminium trialkoxides: Understanding the effects of monomer, alkoxide substituent, solvent and metal. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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6
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Nifant’ev I, Ivchenko P. Coordination Ring-Opening Polymerization of Cyclic Esters: A Critical Overview of DFT Modeling and Visualization of the Reaction Mechanisms. Molecules 2019; 24:E4117. [PMID: 31739538 PMCID: PMC6891794 DOI: 10.3390/molecules24224117] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/09/2019] [Accepted: 11/12/2019] [Indexed: 01/29/2023] Open
Abstract
Ring-opening polymerization (ROP) of cyclic esters (lactones, lactides, cyclic carbonates and phosphates) is an effective tool to synthesize biocompatible and biodegradable polymers. Metal complexes effectively catalyze ROP, a remarkable diversity of the ROP mechanisms prompted the use of density functional theory (DFT) methods for simulation and visualization of the ROP pathways. Optimization of the molecular structures of the key reaction intermediates and transition states has allowed to explain the values of catalytic activities and stereocontrol events. DFT computation data sets might be viewed as a sound basis for the design of novel ROP catalysts and cyclic substrates, for the creation of new types of homo- and copolymers with promising properties. In this review, we summarized the results of DFT modeling of coordination ROP of cyclic esters. The importance to understand the difference between initiation and propagation stages, to consider the possibility of polymer-catalyst coordination, to figure out the key transition states, and other aspects of DFT simulation and visualization of ROP have been also discussed in our review.
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Affiliation(s)
- Ilya Nifant’ev
- Chemistry Department, M.V. Lomonosov Moscow State University, 1 Leninskie Gory Str., Building 3, 119991 Moscow, Russia
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Pr., 119991 Moscow, Russia
| | - Pavel Ivchenko
- Chemistry Department, M.V. Lomonosov Moscow State University, 1 Leninskie Gory Str., Building 3, 119991 Moscow, Russia
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Pr., 119991 Moscow, Russia
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7
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Salomatina EV, Lednev IR, Silina NE, Gracheva EA, Koryagin AS, Smirnova ON, Gorshenin MK, Smirnova LA. Biocompatible compositions based on chitosan and copolymer (lactide–titanium oxide) for engineering of tissue substitutes for wound healing. Polym Bull (Berl) 2019. [DOI: 10.1007/s00289-019-03007-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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8
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Nifant'ev I, Shlyakhtin A, Kosarev M, Gavrilov D, Karchevsky S, Ivchenko P. DFT Visualization and Experimental Evidence of BHT-Mg-Catalyzed Copolymerization of Lactides, Lactones and Ethylene Phosphates. Polymers (Basel) 2019; 11:E1641. [PMID: 31658688 PMCID: PMC6836241 DOI: 10.3390/polym11101641] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 10/05/2019] [Accepted: 10/08/2019] [Indexed: 12/02/2022] Open
Abstract
Catalytic ring-opening polymerization (ROP) of cyclic esters (lactides, lactones) and cyclic ethylene phosphates is an effective way to process materials with regulated hydrophilicity and controlled biodegradability. Random copolymers of cyclic monomers of different chemical nature are highly attractive due to their high variability of characteristics. Aryloxy-alkoxy complexes of non-toxic metals such as derivatives of 2,6-di-tert-butyl-4-methylphenoxy magnesium (BHT-Mg) complexes are effective coordination catalysts for homopolymerization of all types of traditional ROP monomers. In the present paper, we report the results of density functional theory (DFT) modeling of BHT-Mg-catalyzed copolymerization for lactone/lactide, lactone/ethylene phosphate and lactide/ethylene phosphate mixtures. ε-Caprolactone (ε-CL), l-lactide (l-LA) and methyl ethylene phosphate (MeOEP) were used as examples of monomers in DFT simulations by the Gaussian-09 program package with the B3PW91/DGTZVP basis set. Both binuclear and mononuclear reaction mechanistic concepts have been applied for the calculations of the reaction profiles. The results of calculations predict the possibility of the formation of random copolymers based on l-LA/MeOEP, and substantial hindrance of copolymerization for ε-CL/l-LA and ε-CL/MeOEP pairs. From the mechanistic point of view, the formation of highly stable five-membered chelate by the products of l-LA ring-opening and high donor properties of phosphates are the key factors that rule the reactions. The results of DFT modeling have been confirmed by copolymerization experiments.
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Affiliation(s)
- Ilya Nifant'ev
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, 119991 Moscow, Russia.
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Pr., 119991 Moscow, Russia.
| | - Andrey Shlyakhtin
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, 119991 Moscow, Russia.
| | - Maxim Kosarev
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, 119991 Moscow, Russia.
| | - Dmitry Gavrilov
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, 119991 Moscow, Russia.
| | - Stanislav Karchevsky
- Joint-stock company "Institute of petroleum refining and petrochemistry", 12 Iniciativnaya Str., 450065 Ufa, Republic of Bashkortostan, Russia.
| | - Pavel Ivchenko
- Chemistry Department, M.V. Lomonosov Moscow State University, 1-3 Leninskie Gory, 119991 Moscow, Russia.
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Pr., 119991 Moscow, Russia.
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9
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Gümüştaş S, Balcan M, Kınal A. Computational determination of ring opening polymerization reaction mechanism of α-angelica lactone. COMPUT THEOR CHEM 2018. [DOI: 10.1016/j.comptc.2018.08.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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10
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Mili M, Gupta A, Katiyar V. Designing of Poly(l-lactide)-Nicotine Conjugates: Mechanistic and Kinetic Studies and Thermal Release Behavior of Nicotine. ACS OMEGA 2017; 2:6131-6142. [PMID: 31457860 PMCID: PMC6644545 DOI: 10.1021/acsomega.7b01002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 09/15/2017] [Indexed: 06/01/2023]
Abstract
The current work focuses on the ring-opening polymerization (ROP) of l-lactide (LLA) using N-heterocyclic functionalized molecules as an initiator for the synthesis of metal-free poly(l-lactide) (PLLA) conjugates. With this motivation, we have used a drug molecule, nicotine, having N-heterocyclic functionality as the initiator for the synthesis of PLLA conjugates. Structural characterizations carried out using matrix-assisted laser desorption ionization time-of-flight mass spectrometry, Fourier transform infrared, and NMR establish the reacting species during polymerization in the absence of any side reactions. However, side reactions occurred because of the absence of steric hindrance when polymerization is initiated using nicotine in the presence of benzyl alcohol. Accordingly, we report here a detailed investigation on the mechanism of nicotine as an initiator and propose an anionic-based mechanism for the ROP of LLA. Studies on the kinetics parameters have been performed for the nicotine-initiated ROP of LLA and have found that polymerization proceeds with a first-order dependence on both the monomer and initiator concentrations with a low activation energy of 4.9 kcal·mol-1. Further, thermal release studies performed by hyphenated thermogravimetric-Fourier transform infrared analysis found that nicotine is released along with reduced toxins from these synthesized PLLA-nicotine conjugates. Thus, these PLLA-nicotine conjugates can in turn open up a new era in tobacco industries for the preparation of synthetic cigarettes and also in biomedical applications for drug delivery purposes. Herein, a few preliminary experiments using another drug molecule, nicorandil, having similar N-heterocyclic functionality were also conducted to support the role of nicotine as an initiator for the synthesis of PLLA conjugates.
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11
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Chandanabodhi D, Nanok T. A DFT study of the ring-opening polymerization mechanism of l-lactide and ε-caprolactone using aluminium salen-type initiators: Towards an understanding of their reactivities in homo- and copolymerization. MOLECULAR CATALYSIS 2017. [DOI: 10.1016/j.mcat.2017.04.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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12
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Nifant’ev IE, Ivchenko PV, Shlyakhtin AV, Ivanyuk AV. Polymerization of trimethylene carbonate and lactones in the presence of magnesium monoionolate: A comparative theoretical and experimental study. POLYMER SCIENCE SERIES B 2017. [DOI: 10.1134/s1560090417020075] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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13
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Ivchenko PV, Shlyakhtin AV, Nifant’ev IE. Ring-opening polymerization of glycolide and rac -lactide, catalyzed by aryloxy magnesium complexes: DFT study of reaction profile and stereocontrol mechanism. MENDELEEV COMMUNICATIONS 2017. [DOI: 10.1016/j.mencom.2017.05.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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14
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Parwe SP, Warkad SD, Mane MV, Shedage PS, Garnaik B. Investigation of the biocompatibility and cytotoxicity associated with ROP initiator and its role in bulk polymerization of l-lactide. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.01.058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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15
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Vogt-Geisse S, Mata RA, Toro-Labbé A. High level potential energy surface and mechanism of Al(CH3)2OCH3-promoted lactone polymerization: initiation and propagation. Phys Chem Chem Phys 2017; 19:8989-8999. [DOI: 10.1039/c7cp00809k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A hitherto unreported, second transition state (TS2) is the stationary state with the highest relative energy of the Al(CH3)2OCH3 + glycolide initiation reaction.
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Affiliation(s)
- Stefan Vogt-Geisse
- Departamento de Físico-Química
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Millenium Nucleus Chemical Processes and Catalysis (CPC)
- Concepción
| | - Ricardo A. Mata
- Institut für Physikalische Chemie
- Georg-August-Universität Göttingen
- D-37077 Göttingen
- Germany
| | - Alejandro Toro-Labbé
- Nucleus Millennium Chemical Processes and Catalysis
- Laboratorio de Química Teórica Computacional (QTC)
- Departamento de Química-Física
- Facultad de Química
- Pontificia Universidad Católica de Chile
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16
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Grubbs JB, Arnold RM, Roy A, Durie K, Bilbrey JA, Gao J, Locklin J. Degradable Polycaprolactone and Polylactide Homopolymer and Block Copolymer Brushes Prepared by Surface-Initiated Polymerization with Triazabicyclodecene and Zirconium Catalysts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:10183-10189. [PMID: 26317405 DOI: 10.1021/acs.langmuir.5b02093] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Surface-initiated ring-opening polymerization (SI-ROP) of polycaprolactone (PCL) and polylactide (PLA) polymer brushes with controlled degradation rates were prepared on oxide substrates. PCL brushes were polymerized from hydroxyl-terminated monolayers utilizing triazabicyclodecene (TBD) as the polymerization catalyst. A consistent brush thickness of 40 nm could be achieved with a reproducible unique crystalline morphology. The organocatalyzed PCL brushes were chain extended using lactide in the presence of zirconium n-butoxide to successfully grow PCL/PLA block copolymer (PCL-b-PLA) brushes with a final thickness of 55 nm. The degradation properties of "grafted from" PCL brush and the PCL-b-PLA brush were compared to "grafted to" PCL brushes, and we observed that the brush density plays a major role in degradation kinetics. Solutions of methanol/water at pH 14 were used to better solvate the brushes and increase the kinetics of degradation. This framework enables a control of degradation that allows for the precise removal of these coatings.
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Affiliation(s)
- Joe B Grubbs
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
- Meredian Holdings Group - MHG, 140 Industrial Boulevard, Bainbridge, Georgia 39817, United States
| | - Rachelle M Arnold
- Meredian Holdings Group - MHG, 140 Industrial Boulevard, Bainbridge, Georgia 39817, United States
| | - Anandi Roy
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
| | - Karson Durie
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
| | - Jenna A Bilbrey
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
| | - Jing Gao
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
| | - Jason Locklin
- Department of Chemistry, College of Engineering, and the Center for Nanoscale Science and Engineering, University of Georgia , Athens, Georgia 30602, United States
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Gagliardi M, Di Michele F, Mazzolai B, Bifone A. Chemical synthesis of a biodegradable PEGylated copolymer from ε-caprolactone and γ-valerolactone: evaluation of reaction and functional properties. JOURNAL OF POLYMER RESEARCH 2015. [DOI: 10.1007/s10965-015-0661-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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18
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Mandal M, Chakraborty D, Ramkumar V. Zr(iv) complexes containing salan-type ligands: synthesis, structural characterization and role as catalysts towards the polymerization of ε-caprolactone, rac-lactide, ethylene, homopolymerization and copolymerization of epoxides with CO2. RSC Adv 2015. [DOI: 10.1039/c4ra17201a] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Three new Zr(iv) complexes bearing salan-type diamine bis(phenolato) ligands were synthesized and their activities towards the ROP of ε-CL, rac-LA and homopolymerization, copolymerization and coupling of epoxides with CO2 were investigated.
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Affiliation(s)
- Mrinmay Mandal
- Department of Chemistry
- Indian Institute of Technology Patna
- Patna-800 013
- India
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19
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Antimicrobial activity of n-butyl lactate obtained via enzymatic esterification of lactic acid with n-butanol in supercritical trifluoromethane. J Supercrit Fluids 2014. [DOI: 10.1016/j.supflu.2013.11.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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20
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Saha TK, Mandal M, Thunga M, Chakraborty D, Ramkumar V. Imino phenoxide complexes of niobium and tantalum as catalysts for the polymerization of lactides, ε-caprolactone and ethylene. Dalton Trans 2013; 42:10304-14. [PMID: 23736066 DOI: 10.1039/c3dt50752a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Imino phenoxide complexes of Nb and Ta show precise control towards the solvent free ring-opening polymerization of lactides (LA) and ε-caprolactone (CL). There is a close proximity between the observed number average molecular weight (M(n)) and theoretical molecular weight and the molecular weight distributions (MWDs) were found to be narrow. Analysis of low molecular weight oligomers of LA synthesized from these compounds revealed that the ligand is incorporated as one of the end terminal groups in the polymer chain. In addition, these complexes were realized to be precatalysts for the polymerization of ethylene.
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Affiliation(s)
- Tanmoy Kumar Saha
- Department of Chemistry, Indian Institute of Technology Madras, Chennai-600 036, Tamil Nadu, India
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21
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Characteristics and mechanism of L-lactide polymerization using N-heterocyclic carbene organocatalyst. JOURNAL OF POLYMER RESEARCH 2013. [DOI: 10.1007/s10965-013-0087-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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