Review
Chemistry, Inorganic & Nuclear
Ling-Jo Wu, Wei Lee, Prasanna Kumar Ganta, Yu-Lun Chang, Yung -Chi Chang, Hsuan-Ying Chen
Summary: Multinuclear metal complexes can enhance the catalytic activity of ROP catalysts, but the distance between catalytic metal centers and the resonance of ligands play important roles in the catalytic reaction. This review focuses on recent studies of multinuclear metal catalysts in ROP and compares their catalytic activity with mononuclear metal catalysts.
COORDINATION CHEMISTRY REVIEWS
(2023)
Article
Chemistry, Multidisciplinary
Xiaohua Hou, Xiaojian Chen, Xiang Gao, Lei Xu, Hui Zou, Li Zhou, Zong-Quan Wu
Summary: The binuclear vanadium alkylidene showed higher activity in ROMP of norbornene, leading to the formation of cyclic polymers. The size of the polymer ring could be adjusted by the vanadium catalyst structure and polymerization temperature. Similar results were also observed in the ROMP of cyclopentene.
CHINESE JOURNAL OF CHEMISTRY
(2021)
Article
Polymer Science
Sreenath Pappuru, Venkatachalam Ramkumar, Debashis Chakraborty
Summary: Monomeric titanium and zirconium complexes were successfully synthesized and studied for their catalytic activity in the ring-opening polymerization of epsilon-caprolactone and rac-lactide. The single-site zirconium alkoxide complex showed the best catalytic activity, efficiently converting monomers into polymers in high yield under solvent-free conditions within a short period of time.
POLYMERS FOR ADVANCED TECHNOLOGIES
(2021)
Article
Chemistry, Inorganic & Nuclear
Ruyi Chen, Haiyan Ma
Summary: A series of chiral dinuclear magnesium complexes and heterobimetallic dinuclear magnesium complexes were synthesized through reactions with {Mg[N(SiMe3)(2)](2)}(2). The heterobimetallic dinuclear magnesium complexes showed higher activities in the ring-opening polymerization of rac-lactide.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Maosheng Li, Shuai Zhang, Xiaoyong Zhang, Yanchao Wang, Jinlong Chen, Youhua Tao, Xianhong Wang
Summary: The study describes an effective unimolecular anion-binding organocatalysis for ring-opening polymerization of O-carboxyanhydrides (OCAs), achieving the synthesis of highly isotactic poly(phenyllactic acid) (Ph-PLA) through a dynamic cooperative anion-binding mechanism. This approach addresses the challenge of synthesizing high molecular weight stereoregular polyesters by facilitating efficient chain propagation and maintaining high selectivity for OCA ring-opening over side reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Inorganic & Nuclear
Anand J. Gaston, Zoe Greindl, Carole A. Morrison, Jennifer A. Garden
Summary: This study describes four heterobimetallic (salen)Al catalysts and demonstrates that cooperative Al/Mg and Al/Zn combinations can significantly enhance catalyst activity, compared to mono-Al analogues. In contrast, Al/Li and Al/Ca combinations were found to inhibit the polymerization rate. Kinetic and computational studies suggest that chloride bridging in close intermetallic proximity enhances initiation and increases available monomer coordination sites in Al/Mg and Al/Zn complexes. Additionally, ab initio molecular dynamics calculations were utilized to investigate catalyst flexibility and reveal that ligand strain and molecular rigidity can enhance the performance of heterometallic catalysts.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Chang Qiao, Wangyu Shi, Arianna Brandolese, Jordi Benet-Buchholz, Eduardo C. Escudero-Adan, Arjan W. Kleij
Summary: A new catalytic route has been developed for the coupling of epoxides and CO2 to produce polymerizable six-membered bicyclic carbonates. By utilizing cyclic epoxides with a beta-positioned OH group, structurally diverse bicyclic cyclic carbonates can be obtained with good yields and high selectivity. The difference in reactivity between syn- and anti-configured epoxy alcohols is the key to achieve chemo-selectivity, with the anti-isomer leading to the formation of six-membered ring carbonates in the presence of a binary Al-III aminotriphenolate complex/DIPEA catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xuejin Yang, Sean R. Gitter, Allison G. Roessler, Paul M. Zimmerman, Andrew J. Boydston
Summary: Research has found a simple method to control alkene stereochemistry in photoredox mediated metal-free ring-opening metathesis polymerization. Ion-pairing, initiator sterics, and solvation effects each have a profound impact on polynorbornene's stereochemistry. By adjusting reaction conditions, it is possible to control the cis or trans alkene content of PNB.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Inorganic & Nuclear
Ida Ritacco, Maria Voccia, Salvatore Impemba, Matteo Farnesi Camellone, Stefano Milione, Lucia Caporaso
Summary: The mechanism of L-lactide polymerization promoted by NSSN zirconium complexes was investigated using DFT methods to understand how the electronic and steric features of the ligand affect the reaction energy. The rate determining step was found to be the opening of the L-lactide ring, and increasing steric hindrance or electron-withdrawing properties of the ligand increased the energy barrier. However, introducing small and electron-releasing substituents on the nitrogen atom of the ligand, such as a methyl group, improved the activity of NSSN zirconium catalysts in the ROP of L-lactide.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Polymer Science
Nicholas M. M. Shawver, Alicia M. M. Doerr, Brian K. K. Long
Summary: A polymer's properties are determined by the monomers used and the way they are assembled. Polyesters have gained attention as biodegradable alternatives to other petrochemical-based polymers. Researchers have developed redox-switchable catalysts that can alter chemoselectivity and kinetic modulation in ring-opening polymerizations.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Hui Li, Jerome Ollivier, Sophie M. Guillaume, Jean-Francois Carpentier
Summary: This study reports the first chemical synthesis of poly(3-thiobutyrolactone) (P3TB) through ring-opening polymerization. The reactions proceed rapidly in the presence of various metal-based catalysts, and high selectivity can be achieved by manipulating reaction conditions and catalyst systems. The topology and stereochemistry of the resulting polymer have been characterized.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Huan Qiu, Ting Shen, Zhening Yang, Feng Wu, Xiaohong Li, Yingfeng Tu, Jun Ling
Summary: Janus polymerization was utilized to synthesize multiblock copolymers with self-assembly capabilities, good shape memory properties, and potential applications in biomedical devices. The distinguishable chemical structures and thermal properties between Janus MBCPs and cationic random copolymers were confirmed, providing insights into the unique features of Janus polymerization for advanced material design and applications.
CHINESE JOURNAL OF CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Carmine Capacchione, Fabia Grisi, Marina Lamberti, Mina Mazzeo, Barbara Milani, Stefano Milione, Daniela Pappalardo, Cristiano Zuccaccia, Claudio Pellecchia
Summary: Metal catalyzed polymerizations are important chemical reactions, producing 400 million tons of polymeric materials per year, with 50% being polyolefins. The CIRCC research units at the University of Salerno have expertise in this field. Olefin polymerization catalysis continues to interest industrial and academic scientists. There is increasing research on sustainable polymers as alternatives to olefin-based polymers.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Alexey Nikiforov, Natalia Panina, Daniil Blinou, Vladislav Gurzhiy, Juliya Nashchekina, Evgenia Korzhikova-Vlakh, Alexey Eremin, Mariia Stepanova
Summary: This study synthesized and studied carboxylate complexes of nickel(II) with different N-donor ligands for ring-opening polymerization (ROP) of lactide. Among the complexes, [Ni(DBED)(2)(O2CC(CH3)(3))(2)]center dot(CH3)(3)CCO2H showed the highest catalytic ability in the polymerization. A comprehensive density functional theory (DFT) study was conducted to understand the reaction mechanism and the role of carboxylate ligands in the process.
Article
Polymer Science
Mohamed Samir Zaky, Gilles Guichard, Daniel Taton
Summary: This study demonstrates for the first time that an initiator containing a silyl ketene acetal (SKA) group can be used to control the ring-opening polymerization (ROP) of racemic lactide (rac-LA) in the presence of an organic base. This sequential addition strategy expands the scope of organic catalysis in macromolecular engineering of block copolymers involving different propagating species.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Polymer Science
Felix Markus, Johanna R. Bruckner, Stefan Naumann
MACROMOLECULAR CHEMISTRY AND PHYSICS
(2020)
Article
Chemistry, Organic
Patrick Walther, Charlotte Vogler, Stefan Naumann
Article
Biochemistry & Molecular Biology
Nils von Seggern, Tamara Schindler, Stefan Naumann
Review
Polymer Science
Stefan Naumann
Summary: Since 2016, there has been an increased interest in the use of simple triethylborane (Et3B) as a catalyst for the copolymerization of epoxides and carbon dioxide. This catalyst has demonstrated improved functional group tolerance, polymerization control, and practical aspects such as low catalyst loadings and metal-free setups. These advancements have allowed for more precise synthesis of polyethers, complex architectures, and epoxide-based copolymers, leading to extended and novel applications in various fields. This review highlights the catalytic performance of Et3B, strategies for catalyst design, and their impact on polymer properties.
Article
Chemistry, Multidisciplinary
Ayla Sirin-Sariaslan, Stefan Naumann
Summary: This article presents chiral diborane polymerization catalysts with 3,30-disubstituted binaphthol-backbones. These compounds deliver isotactic poly(propylene oxide) with high isotactic diad (m) and triad (mm) placements of up to 92% and 480%, respectively, from racemic monomer.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Ayla Sirin-Sariaslan, Stefan Naumann
Summary: The stereoselective polymerization of epoxides can be achieved with organocatalysts, resulting in well-defined and high molar mass polyethers. This method also allows the incorporation of stereocontrolled polyether blocks in complex polymer architectures.
Article
Polymer Science
Christian Czysch, Thi Dinh, Yannick Froeder, Leon Bixenmann, Patric Komforth, Alexander Balint, Hans-Joachim Raeder, Stefan Naumann, Lutz Nuhn
Summary: In this study, N-heterocyclic olefins (NHOs) were utilized as catalysts for the ring-opening polymerization (ROP) of functional aliphatic carbonates. The research demonstrated that by tuning the reactivity of NHO and introducing a cocatalysis system, controlled and narrowly distributed polymers could be obtained. Furthermore, the feasibility of these catalysts for bioapplications and the successful assembly of nanoparticular structures were highlighted.
Article
Chemistry, Physical
Charlotte Vogler, Stefan Naumann, Johanna R. Bruckner
Summary: The influence of confinement in the nanometer scale has gained attention in the scientific community, particularly in the areas of diffusion, adsorption, phase transition, and catalytic conversion. This study presents a simple method to prepare mesoporous silica materials with narrow pore size distributions and a wide range of pore diameters. The use of tailor-made block copolymers allows for a predictive synthesis, and the application of true liquid crystal templating process guarantees exceptionally narrow pore size distributions, even for ultra-large mesopores.
MOLECULAR SYSTEMS DESIGN & ENGINEERING
(2022)
Article
Polymer Science
Alexander Balint, Stefan Naumann
Summary: By utilizing catalyst pairs of N-heterocyclic olefins (NHOs) and metal-based Lewis acids for lactide polymerization, precise control over polymerization mechanism and NHO placement with quantitative selectivity is achievable. The co-catalytic approach proves superior to metal-free polymerization, providing access to well-defined PLA or high reaction rates. The dominance of metal halide in determining general polymerization performance and stereoselectivity is emphasized, showcasing the potential for preparing specific PLA structures through manipulation of catalyst setup.
Article
Nanoscience & Nanotechnology
Felix Markus, Charlotte Vogler, Johanna R. Bruckner, Stefan Naumann
Summary: By using an organocatalytic polymerization method, well-defined amphiphilic block copolyethers can be prepared and applied as structure-directing agents in a standard soft templating process to deliver ordered mesoporous carbons with monomodal and narrowly distributed pore diameters. Selective tuning of pore diameters in the range of 6-18 nm is achievable by judiciously choosing the properties of the structure-directing agents, potentially reducing the effort required to obtain systematically altered materials.
ACS APPLIED NANO MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Charlotte Vogler, Stefan Naumann
Article
Chemistry, Multidisciplinary
Stefan Naumann
CHEMICAL COMMUNICATIONS
(2019)
