Download or read book Ring opening Metathesis Polymerization of Substituted Cyclopropenes written by Benjamin Ross Elling and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Life would not be possible without precise macromolecular sequence control. The ability of biological systems to encode information, transmit instructions, and catalyze chemical reactions relies on the proper ordering of monomeric units. While our synthetic capabilities may trail those nature has developed through billions of years of evolution, continued advances in polymer science have allowed ever greater control over polymer microstructures. Specifically, living polymerization techniques, such as ring-opening metathesis polymerization (ROMP), have given us the tools to synthesize polymers with defined molecular weights and narrow molecular weight distributions. While ROMP is typically driven by the release of ring strain, surprisingly little research has been performed on the polymerization of cyclopropenes (CPEs), the monocyclic olefin with the highest ring strain. We believed that the high strain energy of this class of monomers along with the ability to tune the steric environment through strategic substitutions would result in unique reactivity and potential to control monomer sequences. In building a library of CPEs capable of ROMP, we discovered a unique class of CPEs that only singly added to Grubbs third generation catalyst followed by no further homopolymerization. We have used this behavior to develop a system for perfectly alternating ROMP with CPEs and low-strain cyclic olefins. Further investigations have shown that this technique can be extended to incorporate other low-strain cycles, allowing for functionalities to be directly incorporated into the polymer backbone. Additionally, with these molecules in hand, we have been able to incorporate single functional units into a polymer backbone by addition of precisely one equivalent of monomer relative to catalyst. At first using this technique to synthesize telechelic polymers, we have successfully optimized this system to allow the incorporation of exactly one monomer into a ROMP polymer at any defined location along the backbone, giving unprecedented control over polymer sequence using via solution chemistry.

Download or read book Ring opening Metathesis Polymerization of Cyclopropenes and Ladderenes written by Jessica Kalay Su and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of polymer microstructure is manifested in nature, where the precisely regulated monomer sequence in biomacromolecules enables their controlled folding and assembly to afford vital biological functions. In the pursuit of man-made materials with sophisticated properties, the field of polymer chemistry has developed rapidly to enable the synthesis of polymers with controlled microstructures. Specifically, living polymerization techniques, such as ring-opening metathesis polymerization (ROMP), enable excellent control over polymer molecular weight, composition, and architecture. ROMP is driven primarily by the release of ring strain in cyclic olefin monomers, but surprisingly few studies have been performed on the ROMP of cyclopropenes (CPEs), the most strained monocyclic olefins. In 2015, our group discovered that a class of 1,1-disubstituted CPE undergoes selective single addition to Grubbs third generation catalyst. Monomers which undergo single addition are extremely rare for chain-growth polymerizations and are particularly useful for manipulating the monomer sequence in a polymer. As such, we focused our research efforts on discovering other CPEs that can undergo single addition and uncovering the mechanism and role of their substituents. We have synthesized a library of CPEs with various disubstitution patterns and substituents and systematically investigated their reactivity with Grubbs catalyst. We have found that 1,1-disubstitution of CPE is crucial for both preserving the stability of the propagating chain end and tuning the metathesis reactivity from living polymerization to single addition. The distinct reactivities stemmed from differences in sterics and/or chelation at the Ru alkylidene from C1 substituents after a single CPE ring-opening event, affecting the barrier to propagation. We have utilized the single addition reactivity of CPEs to synthesize alternating copolymers with diverse side chain and backbone functionalities from alternating ROMP of CPE with low-strain cyclic olefins. Recently, we have developed a strategy to precisely place discrete functionalities and side chains via ring-opened CPEs at pre-determined locations along a living ROMP polymer chain, with control over the location and number incorporated. This advance in polymer chemistry opens many exciting opportunities to manipulate the functionalities along well-controlled polymer chains for understanding the effects of their placement and sequence on polymer behaviors, controlling polymer folding/assembly, as well as synthesizing polymers with more complex nonlinear architectures with precision. Our group also recently reported a unique polymechanophore system, polyladderene, that undergoes force-triggered rearrangement into semi-conducting, insoluble polyacetylene. A notable feature in the design was the terminal strained cyclobutene on ladderene that allowed rapid ROMP. We have developed synthetic procedures to prepare triblock copolymers containing mechanically active polyladderene, since block copolymers can self-assemble in solution and bulk and facilitate incorporation of polyladderene with common polymers to impart the dramatic stress-response of polyladderene to diverse materials.

Download or read book Ring Opening Metathesis Polymerisation and Related Chemistry written by Ezat Khosravi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the last ASI in Turkey in Sept. 1995, the olefin metathesis has made remarkable strong developments with an incredible speed in various directions. New catalyst systems have been developed which have resulted in the synthesis of novel materials. Other fascinating developments have been the new catalysts for stereoselective metathesis and catalysts with considerable functional group tolerance. These new catalysts in addition to Ring Opening Metathesis Polymerisation (ROMP) and Acyclic Diene Metathesis (ADMET) are now powerful tools for Ring Closing Metathesis (RCM) and have found many applications in the synthesis of natural products. A lot of information has been established about all aspects of the olefin metathesis and there is a vast literature concerning the process, covering the initiators, mechanistic features and applications of this reaction in organic and polymer synthesis. The NATO ASI on rd th ROMP and Related Chemistry took place in Polanica-Zdroj, Poland during 3 to 15 Sept. 2000, to highlight the developments in this area and to discuss the prospects and visions for the year 2000 and beyond. The aims of the ASI were: to provide a platform for dissemination of knowledge; to promote communication between people who have a serious interest in this field of chemistry; to help establishing international scientific contacts and to provide an opportunity for the scientists with an appropriate scientific background to learn of recent developments in this field of science. There were 15 lecturers and 67 participants in this NATO ASI.

Download or read book Ring opening Metathesis Polymerization of 3 substituted Cyclooctenes Initiated by Group 6 Alkylidene Complexes written by Daniel James Kozera and published by . This book was released on 2012 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The highly cis,head-to-tail (cis,HT) selective ring-opening metathesis polymerization of 3-substituted cyclooctenes (3-RCOE; R = methyl, hexyl, phenyl) initiated by high oxidation state M and W alkylidene complexes is described herein. W(NtBu)(CHCMe3)(pyr)(OHMT) combined high cis,HT selectivity (>98% cis,HT) with high activity, achieving 76% conversion of 5000 equivalents of 3-HexCOE after 24 h at room temperature. The resulting cis,HT-poly(3-RCOE)s (R = Me, Hex) were isolated, characterized by 1H and 13C NMR, size-exclusion chromatography, and differential scanning calorimetry, and hydrogenated to generate the corresponding saturated polymer.

Download or read book Catalytic Polymerization of Cycloolefins written by V. Dragutan and published by Elsevier. This book was released on 2000-06-26 with total page 1293 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the most important topics concerning cationic Ziegler-Natta and ring-opening metathesis polymerization of cycloolefins. The work describes the major pathways that cycloolefins can follow under the action of specific catalytic systems, essentially vinyl and ring-opening polymerization, both reaction types allowing the manufacture of distinct products with wide applicability in modern technologies. The comprehensive data available on this subject are logically and systematically selected and reviewed throughout 18 chapters, according to the basic catalytic processes involved, types of monomers and catalysts employed, reaction conditions and application fields. The modern trends in design of chiral metallocene catalysts, well-defined living metathesis catalysts, catalysts tolerant toward functionalities and water systems are highlighted. The book discusses in detail the relevant aspects of these processes including reaction thermodynamics, kinetics, mechanisms and stereochemistry and correlates the structure of produced polymers with their chemical and physical-mechanical properties. Related important topics include Ziegler-Natta polymerization of olefins and dienes, atom transfer radical polymerization of vinyl compounds, metathesis of olefins and acetylenes, acyclic diene metathesis reaction, carbonyl olefination reaction, metathesis polymerization of acetylenes, metathesis degradation of polymers and ring-opening polymerization of heterocycles. Special emphasis is laid upon the manufacture of commerical products, new polymers and copolymers of potential interest for industry and design and synthesis of speciality polymers with particular structures and architectures and desired properties. The book critically evaluates the most recent achievements reported in this field and outlines the modern trends on the research and application of the catalytic processes for cycloolefin polymerization. For the first time, comprehensive information about the published data on the subject up to now is provided for both academic and industrial researchers working in the areas of polymer chemistry, organic and organometallic chemistry, surface science and catalysis, petrochemistry and chemical engineering. This stimulating book offers an enlightening introduction and a quick documentation on the subject as well as a solid background in this field. Moreover, the work offers a wealth of useful information for specialists applying polymers in various scientific and industrial areas.

Download or read book Handbook of Ring Opening Polymerization written by Philippe Dubois and published by John Wiley & Sons. This book was released on 2009-03-02 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive, truly one-stop reference discusses monomers, methods, stereochemistry, industrial applications and more. Chapters written by internationally acclaimed experts in their respective fields cover both basic principles and up-to-date information, ranging from the controlled ring-opening polymerization methods to polymer materials of industrial interest. All main classes of monomers including heterocyclics, cyclic olefins and alkynes, and cycloalkanes, are discussed separately as well as their specificities regarding the ring-opening polymerization techniques, the mechanisms, the degree of control, the properties of the related polymers and their applications. The two last chapters are devoted to the implementation of green chemistry in ring-opening polymerization processes. Of much interest to chemists in academia and industry.

Download or read book Metathesis Polymerization of Olefins and Polymerization of Alkynes written by Yavuz Imamogammalu and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 443 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first NATO Advanced Study Institute on Olefin Metathesis and Polymerization Catalysts was held on September 10-22, 1989 in Akcay, Turkey. Based on the fundamental research of RRSchrock, RGrubbs and K.B.Wagener in the field of ring opening metathesis polymerization (ROMP), acyclic diene metathesis (ADMET) and alkyne polymerization, these areas gained growing interest within the last years. Therefore the second NATO-ASI held on metathesis reactions was on Ring Opening Metathesis Po lymerization of Olefins and Polymerization of Alkynes on September 3-16, 1995 in Akcay, Turkey. The course joined inorganic, organic and polymer chemists to exchange their knowledge in this field. This volume contains the main and short lectures held in Akcay. To include ADMET reactions better into the title of this volume we changed it into: Metathesis Polymerization of Olefins and Alkyne Polymerization. This volume is addressed to research scientists, but also to those who start to work in the area of olefin metathesis and alkyne polymerization. The topics of the course were: mechanism of ROMP reactions/ new catalysts for ROMP/ new products by ROMP/ new catalysts for ADMET/ new products by ADMETI degradation of polymer by metathesis reactions/ alkyne polymerization and metathesis/ industrial application of metathesis reactions. The Advanced Study Institute was generously sponsored by the Scientific Affairs Division of NATO and the editor gratefully acknowledges this sponsorship. We also thank the Members of the Local Organizing Committee for their engagement on a successful NATO-AS!.

Download or read book Highly Conjugated Substituted Polyacetylenes Via the Ring opening Metathesis Polymerization of Monosubstituted Cyclooctatetraenes written by Christopher B. Gorman and published by . This book was released on 1992 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis of Catalysts for Ring Opening Metathesis Polymerization written by Martha Dolan Morton and published by . This book was released on 1993 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ring opening Metathesis Polymerisation of Substituted Norbornadienes written by David George Snowden and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ring Opening Metathesis Polymerization written by and published by . This book was released on 1992 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The central theme of this research is ring opening metathesis polymerization of norbornenes and substituted norbornadienes by well characterized imido alkylidene catalysts of the type M(CHR)(NR')(OR)2 (where R, R', and R are some alkyl or aryl groups), or most recently alkylidyne alkylidene rhenium catalysts of the type Re(CHR)(CR')(OR)2. Initially we focused on developing catalysts that would tolerate functionalities (such as carbonyl groups). The findings concerning the polymerization of 2,3- bistrifluoromethylnorbornadiene suggested that the polymer was virtually all trans and tactic. It is now believed to be syndiotactic. Such materials are highly polarizable above Tg(200 C). A significant fraction of the present effort is being expended toward understanding how this stereoselectivity arises and how it can be controlled by changing the nature of the catalyst.

Download or read book Ring Opening Metathesis Polymerization written by Alexey Lyapkov and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, the olefins metathesis has established itself as a powerful tool for carbon-carbon bonds forming and has found numerous applications in polymer chemistry. One of the important directions of metathesis is the polymerization with cycle opening. A study of new ruthenium catalysts, resistant to the many functional groups effects, has showed the possibility of synthesizing functionalized polymers with unique properties. In this chapter, reactivity and activation parameters of eight different norbornene dicarboxylic acid alkyl esters in the presence of a Hoveyda-Grubbs II catalyst for the ring opening metathesis polymerization were determined by 1H NMR analysis in-situ. The molecules of esters differ in the aliphatic radical structure and the location of the substituent groups. Kinetic studies have shown that effective polymerization constants and activation parameters strongly depend on the monomer structure. It is shown that the elongation of the aliphatic radical does not significantly affect the reactivity, but significantly changes the activation parameters. The branching of the aliphatic radical significantly affects both the reactivity of the corresponding ester and the activation parameters of the polymerization. The position of the substituents in the norbornene ring of the ester also has a significant effect on the activation parameters of metathesis polymerization.

Download or read book Synthesis of Polymers written by Dieter A. Schlüter and published by John Wiley & Sons. This book was released on 2012-05-14 with total page 1229 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers are huge macromolecules composed of repeating structural units. While polymer in popular usage suggests plastic, the term actually refers to a large class of natural and synthetic materials. Due to the extraordinary range of properties accessible, polymers have come to play an essential and ubiquitous role in everyday life - from plastics and elastomers on the one hand to natural biopolymers such as DNA and proteins on the other hand. The study of polymer science begins with understanding the methods in which these materials are synthesized. Polymer synthesis is a complex procedure and can take place in a variety of ways. This book brings together the "Who is who" of polymer science to give the readers an overview of the large field of polymer synthesis. It is a one-stop reference and a must-have for all Chemists, Polymer Chemists, Chemists in Industry, and Materials Scientists.

Download or read book Advances in Ring Opening Metathesis Polymerization written by and published by Wiley-VCH. This book was released on 2000-09-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume of Macromolecular Symposia contains contributions presented at the RO(M)P'99 International Symposium in Mons, Belgium. At this meeting, over one hundred chemists, physico-chemists, chemical engineers from the world of academia and industry, as well as students, discussed recent developments in mechanisms and kinetics in RO(M)P, synthesis and characterization of new macromolecular architectures, and new materials and applications via RO(M)P.

Download or read book Polymerization of Heterocycles Ring Opening written by S. Penczek and published by Elsevier. This book was released on 2016-02-03 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymerization of Heterocycles (Ring Opening) is a collection of papers presented at the International Symposium on Polymerization of Heterocycles (Ring-Opening) held in Warsaw, Poland on June 23-25, 1975. The first paper describes the developments and physical meaning of ion pairs and higher ionic aggregates. Another paper explains the process of obtaining linear polymers, containing rings in the main chain. The book interprets the various behaviors of polymers that can result in high optical yields of stereoelectivity ratios equal to 8. The text then discusses future trends in aldehyde and carbonyl polymerization, including some problem areas pertaining to failures to homopolymerize or copolymerize tetrachloroethylene oxide. Another paper reviews the elemental reactions of selected combinations of copolymerization; the next paper discuses aspects of the mechanism of nucleophilic opening of epoxide rings through studies of certain kinetics. The book then analyzes the ability of lactams to undergo ring-opening polymerization, which mainly depends on the ring size and on the substitution and presence of heteroatoms in the lactam ring itself. The text also discusses the preparation, properties, and applications of the heterochain polymers in medicine or biologically active materials. The book can provide useful information for biochemists, researchers dealing with inorganic and organic compounds, and scientists working in the fields of chemistry such as synthetic chemistry, as well as polymer engineering.

Download or read book Reagents Auxiliaries and Catalysts for C C Bond Formation written by Robert M. Coates and published by John Wiley & Sons. This book was released on 1999-07-09 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Reagents for Organic Synthesis Reagents, Auxiliaries and Catalysts for C-C Bond Formation Robert M. Coates and Scott E. Denmark The University of Illinois, Urbana, USA Recognising the critical need for bringing a handy reference work that deals with the most popular reagents in synthesis to the laboratory of practising organic chemists, the Editors, of the acclaimed Encyclopedia of Reagents for Organic Synthesis (EROS) have selected the most important and useful reagents employed in contemporary organic synthesis. The Handbook of Reagents for Organic Synthesis; Reagents Auxiliaries and Catalysts for C-C Bond Formation, provides practical and concise information on a diverse group of reagents. To familiarise the user with the spectrum of reagents contained within this volume, the editors have subdivided more than 200 entries into 22 classes based on their chemical structures and function. The articles, arranged alphabetically, contain all of the information found in EROS as well as expanded reagents listings. In addition, new listings of recently published review articles and monographs are included, as well as relevant Organic Syntheses procedures that deal with either the preparations or reactions of the featured reagents. This comprehensive and well referenced handbook will prove of great value to all practitioners in the field of organic chemistry.

Download or read book Handbook of Metathesis 3 Volume Set written by Robert H. Grubbs and published by John Wiley & Sons. This book was released on 2015-05-26 with total page 1639 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the complete breadth of the olefin metathesis reaction. The second edition of the ultimate reference in this field is completely updated and features more than 80% new content, with the focus on new developments in the field, especially in industrial applications. No other book covers the topic in such a comprehensive manner and in such high quality, and this new edition retains the three-volume format: Catalyst Development, Applications in Organic Synthesis and Polymer Synthesis. Edited by a Nobel laureate in the field, and with a list of contributors that reads like a "Who's-Who" of metathesis, this is an indispensable one-stop reference for organic, polymer and industrial chemists, as well as chemists working with organometallics. Individual volumes also available separately to purchase Volume 1: Catalyst Development - http://www.wiley.com/WileyCDA/WileyTitle/productCd-3527339485.html Volume 2: Applications in Organic Synthesis - http://www.wiley.com/WileyCDA/WileyTitle/productCd-3527339493.html Volume 3: Polymer Synthesis - http://www.wiley.com/WileyCDA/WileyTitle/productCd-3527339507.html