An Easy Synthetic Route to Heteroleptic Samarium Monoalkoxides for Ring-Opening Polymerization Initiators. Molecular Structures of [(C5Hi-Pr4)SmI(THF)2]2, SmI2Ot-Bu(THF)4, and (C4Me4P)2SmOt-Bu(THF)

Abstract The reaction of lithium β-diketiminate [{2,6-Me2C6H3N=CMe}2CH]Li with benzophenone in toluene at 25°C affords the coordination complex [{2,6-Me2C6H3N=CMe}2CH]Li(Ph2C=O) (I). New keto-β-diketimine {2,6-Me2C6H3N=C(Me)}2CHC(tert-Bu)=O (II) is synthesized by the reaction of tert-Bu(C=O)Cl with [{2,6-Me2C6H3N=CMe}2CH]Li. The metallation of keto-β-diketimine II with n-butyllithium in THF at 0°C gives lithium keto-β-diketiminate {[{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]Li(THF)}n (III). The exchange reaction of YCl3 with compound III (molar ratio 1 : 2, THF) affords the yttrium bis(keto-diketiminate) complex [{2,6-Me2C6H3N=C(Me)}2CС(tert-Bu)=O]2Y(μ2-Cl)2L-(THF)2 (IV). The molecular structures of complexes I, III, and IV are determined by X-ray diffraction analysis (CIF files CCDC nos. 2001131 (I), 2001132 (III), and 2001133 (IV)). Complex IV in the crystalline state exists as an ate complex with one LiCl molecule. Complexes I, III, and IV are catalysts of ring-opening polymerization of ε-caprolactone in toluene at 25°С.

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Green and sustainable synthesis of poly(δ-valerolactone) with TBD catalyzed ring-opening polymerization reaction

Reaction Chemistry & Engineering ◽

10.1039/d1re00434d ◽

2021 ◽

Author(s):

Kai Cheng ◽

Shiyao Lu ◽

Kai Wang ◽

Guangsheng Luo

Keyword(s):

Efficient Method ◽

Ring Opening ◽

Ring Opening Polymerization ◽

Polymerization Reaction ◽

Aliphatic Polyester ◽

Synthetic Route ◽

Highly Efficient

Ring-opening polymerization (ROP) of lactones catalyzed by 1,5,7-triazabicyclo[4,4,0]decane-5-ene (TBD) is a highly efficient method for synthesizing aliphatic polyester materials. In order to create a green and sustainable synthetic route of...

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Use of Titanium Complexes Bearing Diphenolate or Calix[n]arene Ligands in α-Olefin Polymerization and the ROP of Cyclic Esters

Catalysts ◽

10.3390/catal10020210 ◽

2020 ◽

Vol 10 (2) ◽

pp. 210 ◽

Cited By ~ 5

Author(s):

Orlando Santoro ◽

Carl Redshaw

Keyword(s):

Ring Opening ◽

Olefin Polymerization ◽

Ring Opening Polymerization ◽

Molecular Structures ◽

Titanium Complexes ◽

Cyclic Esters ◽

Arene Ligands ◽

Catalytic Behaviour

In this review, we discuss the use of titanium complexes bearing either bridged diphenolate or calix[n]arene (n = 4, 6, 8) ligation, in the formation of plastics from α-olefins or via the ring opening polymerization (ROP) of cyclic esters. The syntheses, molecular structures and catalytic behaviour of these systems are discussed, as well as where possible, the properties of the resultant polymers.

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Towards a selective synthetic route for cobalt amino acid complexes and their application in ring opening polymerization of rac-lactide

RSC Advances ◽

10.1039/d1ra02909f ◽

2021 ◽

Vol 11 (27) ◽

pp. 16326-16338

Author(s):

Andrés Castro Ruiz ◽

Krishna K. Damodaran ◽

Sigridur G. Suman

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Ring Opening ◽

Ring Opening Polymerization ◽

Oxidation States ◽

Synthetic Route ◽

Coordination Properties ◽

Amino Acid Complexes ◽

Ligand Coordination

Catalysts based on Co, amino acids, and 2,2-bipyridine present an attractive and economic alternative in ring opening polymerization, and possess advantageous ligand coordination properties combined with a variety of accessible oxidation states and coordination geometries.

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Pentamethylcyclopentadienyl Molybdenum(V) Complexes Derived from Iodoanilines: Synthesis, Structure, and ROP of ε-Caprolactone

Catalysts ◽

10.3390/catal11121554 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1554

Author(s):

Tian Xing ◽

Mark R. J. Elsegood ◽

Sophie H. Dale ◽

Carl Redshaw

Keyword(s):

Molecular Weight ◽

Comparative Studies ◽

Ring Opening ◽

Kinetic Studies ◽

Ring Opening Polymerization ◽

Molecular Structures ◽

Low Molecular Weight ◽

End Groups ◽

Amine Complex ◽

Reaction Stoichiometry

The reaction of [Mo(η-C5Me5)Cl4] with the ortho-, meta-, or para-iodo-functionalized anilines 2-IC6H4NH2, 3-IC6H4NH2, 4-IC6H4NH2 yields imido or amine products of the type [Mo(η-C5Me5)Cl2(IC6H4N)] (2-I, 1, 3-I, 3, 4-I, 5) or [Mo(η-C5Me5)Cl4(IC6H4NH2)] (3-I, 2, 4-I, 4), respectively, depending on the reaction stoichiometry/conditions; we were unable to isolate an amine complex of the 2-I derivative. The reaction of [Mo(η-C5Me5)Cl4] with one equivalent of 2-I,4-FC6H3NH2 in the presence of Et3N afforded [Mo(η-C5Me5)Cl2(2-I,4-FC6H3N)]·MeCN (6·MeCN), which, upon exposure to air, afforded the Mo(VI) imido complex [Mo(η-C5Me5)Cl3(2-I,4-FC6H3N)] (7). For comparative studies, the structure of the aniline (C6H5NH2)-derived complex [Mo(η-C5Me5)Cl2(2-C6H3N)] (8) has also been prepared. The molecular structures of 1–8 have been determined and reveal packing in the form of zig-zag chains or ladders. The complexes catalyze, in the presence of benzyl alcohol under N2, the ring-opening polymerization (ROP) of ε-caprolactone affording relatively low molecular weight products. The MALDI-ToF spectra indicate that a number of polymer series bearing a variety of end groups are formed. Conducting the ROPs as melts or under air results in the isolation of higher molecular weight products, again bearing a variety of end groups. Kinetic studies reveal the aniline-derived imido complex 8 performs best, whilst a meta-iodo substituent and a Mo(V) centre are also found to be beneficial. The structures of the side products 2-IC6H4NH3Cl and 3-IC6H4NH3Cl are also reported.

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Strain-induced ring-opening polymerization of ferrocenylorganocyclotriphosphazenes: a new synthetic route to poly(organophosphazenes)

Journal of the American Chemical Society ◽

10.1021/ja00025a026 ◽

1991 ◽

Vol 113 (25) ◽

pp. 9596-9603 ◽

Cited By ~ 26

Author(s):

Harry R. Allcock ◽

Jeffrey A. Dodge ◽

Ian Manners ◽

Geoffrey H. Riding

Keyword(s):

Ring Opening ◽

Ring Opening Polymerization ◽

Synthetic Route

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Coordination Ring-Opening Polymerization of Cyclic Esters: A Critical Overview of DFT Modeling and Visualization of the Reaction Mechanisms

Molecules ◽

10.3390/molecules24224117 ◽

2019 ◽

Vol 24 (22) ◽

pp. 4117 ◽

Cited By ~ 9

Author(s):

Ilya Nifant’ev ◽

Pavel Ivchenko

Keyword(s):

Ring Opening ◽

Density Functional ◽

Transition States ◽

Ring Opening Polymerization ◽

Molecular Structures ◽

Data Sets ◽

Dft Methods ◽

Cyclic Esters ◽

Dft Modeling ◽

The Difference

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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Synthesis and properties of a temperature-sensitive hydrogel based on physical crosslinking via stereocomplexation of PLLA-PDLA

RSC Advances ◽

10.1039/d0ra01790f ◽

2020 ◽

Vol 10 (34) ◽

pp. 19759-19769 ◽

Cited By ~ 3

Author(s):

Xiaoyu Shi ◽

Jie Wu ◽

Zhidan Wang ◽

Fei Song ◽

Wenli Gao ◽

...

Keyword(s):

Radical Polymerization ◽

Ring Opening ◽

Ring Opening Polymerization ◽

Temperature Sensitive ◽

Synthetic Route ◽

Temperature Sensitive Hydrogel ◽

Physical Crosslinking

A synthetic route to amphiphilic conetwork (APCN) gels was developed and involved (1) ring-opening polymerization synthesis of the macromonomer, and (2) radical polymerization of stereocomplex of the synthesized macromonomers with MEO2MA, OEGMA to form the APCN gels.

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