Download or read book Novel Group Four Complexes for the Polymerization and Copolymerization of Olefins written by Matthew N. Herzog and published by . This book was released on 2003 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oxygen Based Group 4 Complexes as Catalysts for Olefin and Styrene Polymerization written by Carmine Capacchione and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Group 4 Metal Octahedral Complexes as Catalysts for Olefin Polymerization written by Marina Lamberti and published by . This book was released on 2003 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Olefin Polymerization Using Group 4 Cyclopentadienyl amido Catalysts written by Andrew Leland McKnight and published by . This book was released on 1997 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Group 4 Complexes Bearing Tridentate Aryloxide Based Ancillary Ligands written by Ka-Ho Tam and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Group 4 Complexes Bearing Tridentate Aryloxide-based Ancillary Ligands: Synthesis, Characterization and Application as Olefin Polymerization Catalysts" by Ka-ho, Tam, 譚家豪, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled GROUP 4 COMPLEXES BEARING TRIDENTATE ARYLOXIDE- BASED ANCILLARY LIGANDS: SYNTHESIS, CHARACTERIZATION AND APPLICATION AS OLEFIN POLYMERIZATION CATALYSTS Submitted by Tam Ka Ho for the degree of Doctor of Philosophy at The University of Hong Kong in 2006 The preparation, characterization, crystal structures and olefin polymerization behavior of a class of Group 4 complexes, and in particular the Zr(IV) derivatives 1 1 [Zr(L )Cl (D)] [H L = 2,6-di(3-tert-butyl-5-methylphen-2-ol)pyridine; D = ethers, 2 2 ketones and Cl(HPR )], have been undertaken. These [O, N, O] catalysts exhibit excellent activities with MAO for ethylene polymerization. Studies to assess the impact of the donor group during catalysis suggest that the same active species is generated and the donor does not play an active role. Superior activities were observed with the Bu Al/Ph CB(C F ) cocatalyst in ethylene polymerization and - 3 3 6 5 4 -1 -1 propylene copolymerization (36,590 and 15,700 g mmol h respectively). Insight into the behavior of the catalytic system with MAO has been derived from gel permeation chromatography and NMR analyses of the polymers prepared under 1 13 different reaction conditions. H and C NMR end-group analyses reveal resonances for saturated methyl chain-end groups only, and undetectable levels of unsaturated vinyl chain ends. This indicates that for the polymerization chain-transfer mechanism, the conventional β-H transfer reactions are insignificant and the unusual chain transfer to Al pathway is vastly dominant. Group 4 complexes supported by unsymmetric tridentate [O, N, O] ligands bearing different substituents on the two aryloxide rings have been prepared, in order to develop new catalytic systems capable of stereospecific α-olefin polymerization. Their activities for ethylene polymerization with MAO are significantly lower than the symmetric [O, N, O] analogues. A number of group 4 bis(benzyl) complexes supported by tridentate pyridine-2- phenolate-6-aryl [O, N, C] ligands, with alkyl and halogen substituents at the R position ortho to the metal, have been prepared. This enabled direct comparison with the CF -substituted [O, N, C] analogues, which were recently reported to exhibit novel C-H---F-C contacts in solution with potential applications for attractive ligand---polymer interactions. The molecular structure of the Zr derivative bearing an ortho-Cl group was determined, revealing the benzyl moieties in an unusual 'anti, anti' configuration. Saliently, this polyethylene catalyst in conjunction with Bu Al/Ph CB(C F ) displayed the best activity thus far observed for [O, N, C] 3 3 6 5 4 -1 -1 catalysts (8630 g mmol h ). A series of group 4 bis(benzyl) complexes supported by newly designed [O, C, N] ligands bearing R substituents ortho to the metal has been prepared, such that the σ- aryl moiety resides trans to the alkyl/polymer chain, and catalyst decomposition pathways such as olefin insertion into the M-C(sp ) bond are impeded. The crystal structure of the CF -substituted hafnium(IV) complex features weak intramolecular 31 C-H---F-C (CF ---methylene) interactions. The H NMR spectra of [M(O, C, N- CF )(CH Ph) ] analogues revealed coupling (assigned to J [via M---F] for Hf and

Download or read book Octahedral Bis phenolate Ether Group IV Metal Complexes for Polymerization and Copolymerization of Alpha olefins written by Elizabeth Tanzini Kiesewetter and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Octahedral group IV bis(phenolate) ether complexes, activated by methylaluminoxane, are highly active and stereospecific [alpha]-olefin polymerization catalysts. X-ray crystallographic analysis reveals the Zr and Hf complexes to be closely isostructural; the bond lengths of the Hf complex are slightly shorter, but the maximum deviation is only 0.062 Å. Despite the structural similarity of the Hf and Zr complexes, the Hf complexes generate more highly stereoselective catalysts. In addition to the influence of the transition metal, the structure of the ligand has a large influence on the stereospecificity. Bis-t-Butyl phenyl substituted complexes of Hf and Zr, when activated by MAO at 50 - 80 °C, generate high molecular weight polypropylene (Mn = 130,000 - 360,000 g/mol) with isotacticities [mmmm]> 0.97 and melting points as high as 165°C. Octahedral group IV bisphenolate ether complexes, activated by methylaluminoxane, were also tested in propylene polymerization in the presence diethyl zinc. Although the Hf and Zr complexes are structurally similar, propylene polymerization behavior of the two catalysts differs significantly in terms of productivity, isospecificity and propensity to incorporate specific regioerrors. 13C-NMR analysis revealed that the type and the number of regioerrors being incorporated into the polymer chain are strongly dependent on the identity of the ligand and the metal. Low molecular weight polypropylene oligomers (Mn = 1700 - 9900 g/mol), generated in the presence of diethyl zinc facilitated end group analysis, which revealed the presence of isobutyl and 2-methylbutyl groups. Octahedral bis(phenolate) catalysts are highly active catalysts for the isospecific polymerization of 1-hexene and the production of high molecular weight ethylene/1-hexene copolymers. These catalysts are active for the production of high molecular weight copolymers even at high temperatures. The reactivity ratios for these complexes were determined; all of the bis(phenolate) complexes tested showed reasonable 1-hexene incorporations. The complexes prepared from the more sterically demanding ligands showed higher incorporations of comonomers than those prepared from the less sterically demanding ligands. Complexes of the type Cp*TiX2(ONR'R'') (Cp* = [Eta]5-C5Me5, X = Me, Cl; R = Et, TEMPO (2,2,6,6-tetramethylpiperidine-N-oxyl); X = R' = Me, R'' = tBu) were synthesized by several routes. Upon activation with [Ph3C]+[B(C6F5)4]- and AliBu3, these complexes generate highly active catalysts for propylene polymerization, although significant catalyst deactivation was observed. Activation with B(C6F5)3/AliBu3 or methylaluminoxane (MAO) resulted in reduced polymerization activity; the latter leading to increased catalyst lifetime. Reaction of Cp*Ti(Me)2(ONEt2) and Cp*Ti(Me)2(ONtBu(Me)) with B(C6F5)3 resulted in clean formation of the zwitterionic contact ion pairs, [Cp*Ti(Me)([Eta]2-ONEt2)]+[MeB(C6F5)3]- and [Cp*Ti(Me)([Eta]2-ONtBu(Me))]+[MeB(C6F5)3]- respectively whereas reaction of Cp*Ti(Me)2([Eta]2-ONtBu(Me)) with [Ph3C]+[B(C6F5)4]- resulted in the clean formation of the solvent-separated ion pair [Cp*Ti(Me)([Eta]2-ONtBu(Me))]+[B(C6F5)4]-. Addition of AliBu3 or AlMe3 to the cationic [Cp*Ti(Me)(ONtBu(Me))]+[B(C6F5)4]- resulted in decomposition of the cations.

Download or read book Alkene Polymerization Reactions with Transition Metal Catalysts written by Yury Kissin and published by Elsevier. This book was released on 2008-03-10 with total page 607 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past 30 years, the field of alkene polymerization over transition metal catalysts underwent several major changes:1. The list of commercial heterogeneous Ziegler-Natta catalysts for the synthesis of polyethylene and stereoregular polyolefins was completely renewed affording an unprecedented degree of control over the polymer structure.2. Research devoted to metallocene and other soluble transition-metal catalysis has vastly expanded and has shifted toward complexes of transition metals with multidentate ligands.3. Recent developments in gel permeation chromatography, temperature-rising fractionation, and crystallization fractionation provided the first reliable information about differences between various active centers in transition-metal catalysts.4. A rapid development of high-resolution 13C NMR spectroscopy resulted in greatly expanded understanding of the chemical and steric features of polyolefins and alkene copolymers. These developments require a new review of all aspects of alkene polymerization reactions with transition-metal catalysts. The first chapter in the book is an introductory text for researchers who are entering the field. It describes the basic principles of polymerization reactions with transition-metal catalysts, the types of catalysts, and commercially manufactured polyolefins. The next chapter addresses the principal issue of alkene polymerization catalysis: the existence of catalyst systems with single and multiple types of active centers. The subsequent chapters are devoted to chemistry and stereochemistry of elemental reaction steps, structures of catalyst precursors and reactions leading to the formation of active centers, kinetics of polymerization reactions, and their mechanisms. The book describes the latest commercial polymerization catalysts for the synthesis of polyethylenes and polypropylene The book provides a detailed description of the multi-center nature of commercial Ziegler-Natta catalysts. The book devotes specialized chapters to the most important aspects of transition metal polymerization catalysts: the reactions leading to the formation of active centers, the chemistry and stereochemistry of elemental polymerization steps, reaction kinetics, and the polymerization mechanism. The book contains an introductory chapter for researchers who are entering the field of polymerization catalysis. It describes the basic principles of polymerization reactions with transition-metal catalysts and the types of commercially manufactured polyolefins and copolymersThe book contains over 2000 references, the most recent up to end of 2006.

Download or read book Group 4 Amidinate Complexes as Olefin Polymerisation Catalysts written by Richard T. W. Scott and published by . This book was released on 2013 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polymer Science A Comprehensive Reference written by and published by Newnes. This book was released on 2012-12-05 with total page 7752 pages. Available in PDF, EPUB and Kindle. Book excerpt: The progress in polymer science is revealed in the chapters of Polymer Science: A Comprehensive Reference, Ten Volume Set. In Volume 1, this is reflected in the improved understanding of the properties of polymers in solution, in bulk and in confined situations such as in thin films. Volume 2 addresses new characterization techniques, such as high resolution optical microscopy, scanning probe microscopy and other procedures for surface and interface characterization. Volume 3 presents the great progress achieved in precise synthetic polymerization techniques for vinyl monomers to control macromolecular architecture: the development of metallocene and post-metallocene catalysis for olefin polymerization, new ionic polymerization procedures, and atom transfer radical polymerization, nitroxide mediated polymerization, and reversible addition-fragmentation chain transfer systems as the most often used controlled/living radical polymerization methods. Volume 4 is devoted to kinetics, mechanisms and applications of ring opening polymerization of heterocyclic monomers and cycloolefins (ROMP), as well as to various less common polymerization techniques. Polycondensation and non-chain polymerizations, including dendrimer synthesis and various "click" procedures, are covered in Volume 5. Volume 6 focuses on several aspects of controlled macromolecular architectures and soft nano-objects including hybrids and bioconjugates. Many of the achievements would have not been possible without new characterization techniques like AFM that allowed direct imaging of single molecules and nano-objects with a precision available only recently. An entirely new aspect in polymer science is based on the combination of bottom-up methods such as polymer synthesis and molecularly programmed self-assembly with top-down structuring such as lithography and surface templating, as presented in Volume 7. It encompasses polymer and nanoparticle assembly in bulk and under confined conditions or influenced by an external field, including thin films, inorganic-organic hybrids, or nanofibers. Volume 8 expands these concepts focusing on applications in advanced technologies, e.g. in electronic industry and centers on combination with top down approach and functional properties like conductivity. Another type of functionality that is of rapidly increasing importance in polymer science is introduced in volume 9. It deals with various aspects of polymers in biology and medicine, including the response of living cells and tissue to the contact with biofunctional particles and surfaces. The last volume is devoted to the scope and potential provided by environmentally benign and green polymers, as well as energy-related polymers. They discuss new technologies needed for a sustainable economy in our world of limited resources. Provides broad and in-depth coverage of all aspects of polymer science from synthesis/polymerization, properties, and characterization methods and techniques to nanostructures, sustainability and energy, and biomedical uses of polymers Provides a definitive source for those entering or researching in this area by integrating the multidisciplinary aspects of the science into one unique, up-to-date reference work Electronic version has complete cross-referencing and multi-media components Volume editors are world experts in their field (including a Nobel Prize winner)

Download or read book Isospecific Polymerization of Olefins written by Y.V. Kissin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt: The discoveries of organometallic catalysts for olefin polymerization by Karl Ziegler and that of stereoregular olefin polymers by Giulio Natta are probably the two most important achievements in the areas of catalysis and polymer chemistry in the second half of this century. They led to the development of a new branch of chemical industry, and to a large volume production of high-density and linear low-density polyethylene, isotactic polypropylene, ethylene-propylene rubbers, isotactic poly I-butene, and poly-4-methyl-l-pentene. These discoveries merited the Nobel prize, which was awarded to K. Ziegler and G. Natta in 1963. The initial works of Ziegler and Natta were followed by an "explosion" of scientific papers and patents covering all aspects of polymerization chemistry, catalyst synthesis, and polymerization kinetics as well as the structural, chemical, physical, and technological characteristics of stereo regular polyolefins, polydienes, and olefin copolymers. It is sufficient to say that in the twenty-five years after the first publications more than 15,000 papers and patents appeared on subjects related to the area. . The development brought about the establishment of several prominent groups of scientists occupied with the study of olefin polymerization. The most important of these were scientific schools in Italy, Germany, England, the United States, Japan, the Soviet Union, Czechoslovakia, and Venezuela. In addition, many major chemical and petrochemical corporations throughout the world established labora tories devoted to the development of the technology of catalyst synthesis and olefin polymerization.

Download or read book Olefin Upgrading Catalysis by Nitrogen based Metal Complexes I written by Giuliano Giambastiani and published by Springer Science & Business Media. This book was released on 2011-04-29 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights key advances that have occurred in the field of olefin conversion in recent years. The role of homogenous transition metal catalysts which contain an imine functionality is emphasized; their potential applications in the processing and upgrade of olefins to a wide variety of commodity products of very high industrial value is also explored. On the threshold of the fiftieth anniversary of the Noble Prize to Ziegler and Natta, this book gives a critical summary of the state of the art developments in the fascinating and rapidly developing field of the olefin polymerization, oligomerization, and co-polymerization catalysis.

Download or read book Book of Abstracts XXXII Conference Expert Group Meeting on Organometallic Chemistry written by Elena Fernández and published by PUBLICACIONS UNIVERSITAT ROVIRA I VIRGILI. This book was released on 2014-09-30 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first meeting dedicated to the organometallic chemistry in Spain took place during the eighties, when 40 scientists from our country shared their experiences around this genuine discipline. The first GEQO meeting was held in Alcalá de Henares on June 12, 1981. It was decided to continue with this adventure, and only one year later they met again at the Bienal of Chemistry in Santander, in September 1982. Then, in 1983 it was Tarragona’s turn to takeover, and convert this Meeting into an exciting experience. Three decades later, and casually during the meeting of the Spanish organometallic group in the Bienal of Santander 2013, we announced that the next GEQO-meeting will take place in Tarragona, between September 17-19, 2014. Despite the changes in the host city and its people, one thing still remains the same: the enthusiasm with which this event is being organized and its projection to everyone who sees in organometallic chemistry… a way of thinking in chemistry.

Download or read book Olefin Metathesis and Metathesis Polymerization written by K. J. Ivin and published by Elsevier. This book was released on 1997-01-07 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a follow-up to Ivins Olefin Metathesis, (Academic Press, 1983). Bringing the standard text in the field up to date, this Second Edition is a result of rapid growth in the field, sparked by the discovery of numerous well-defined metal carbene complexes that can act as very efficient initiators of all types of olefin metathesis reaction, including ring-closing metathesis of acyclic dienes, enynes, and dienynes; ring-opening metathesis polymerizationof cycloalkenes, acyclic diene metathesis polymerization; and polymerization of alkynes, as well as simple olefin metathesis. Olefin Metathesis and Metathesis Polymerization provides a broad, up-to-date account of the subject from its beginnings in 1957 to the latest applications in organic synthesis. The book follows the same format as the original, making it useful toteachers and to researchers, and will be of particular interest to those working in the fields of organic chemistry, polymer chemistry, organometallic chemistry, catalysis, materials science and chemical engineering. Discusses different classes of olefin metathesis and the choice of reaction conditions and catalyst Considers commercial processes with examples from existing and new technologies Provides a complete overview of the subject from its beginning to the present day

Download or read book Olefin Upgrading Catalysis by Nitrogen based Metal Complexes II written by Giuliano GIAMBASTIANI and published by Springer Science & Business Media. This book was released on 2011-05-19 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Olefin Upgrading Catalysis by Nitrogen-based Metal Complexes II: State-of-the-art and Perspectives provides a critical review of the state-of-the-art developments in industrially relevant processes connected to efficient and selective olefin upgrading. Specific attention is devoted to catalysts containing imine- and amine-based ligands. All the chapters in this book have been designed to provide a systematic account of the vast amount of information available for this type of catalyst as well as to highlight the factors that ultimately control the catalyst’s performance and productivity. A comprehensive panorama of catalyst precursors is presented, spanning from group 10 α-diimine complexes and iron and cobalt 2,6-bis(imino)pyridine derivatives, to vanadium, chromium, titanium, zirconium and lanthanide complexes supported by nitrogen-containing ligands. The authors of this collective work are currently involved in the development of imine-based catalysts for efficient and selective olefin upgrading and the majority of them have dedicated most of their scientific career to this important field. In writing this book, their major goal is to transfer as many ideas and experiences as possible to the global audience of scientists engaged in this area of research.

Download or read book Computational Quantum Chemistry written by Masoud Soroush and published by Elsevier. This book was released on 2018-10-16 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Quantum Chemistry: Insights into Polymerization Reactions consolidates extensive research results, couples them with computational quantum chemistry (CQC) methods applicable to polymerization reactions, and presents those results systematically. CQC has advanced polymer reaction engineering considerably for the past two decades. The book puts these advances into perspective. It also allows you to access the most up-to-date research and CQC methods applicable to polymerization reactions in a single volume. The content is rigorous yet accessible to graduate students as well as researchers who need a reference of state-of-the-art CQC methods with polymerization applications. Consolidates more than 10 years of theoretical polymerization reaction research currently scattered across journal articles Accessibly presents CQC methods applicable to polymerization reactions Provides researchers with a one-stop source of the latest theoretical developments in polymer reaction engineering

Download or read book Preparation of New Group 4 Amidinate and Triazenide Complexes and Their Activity in the Polymerization of Olefins written by Andrey Torotko and published by . This book was released on 2010 with total page 871 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metal Catalyzed Polymerization written by Samir Chikkali and published by CRC Press. This book was released on 2017-08-03 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proposed book focusses on metal mediated/catalyzed “controlled/living radical polymerization” (CRP/LRP) methods. It surveys a wide variety of catalyzed polymerization reactions, making it essentially a “one stop” review in the field. A significant contribution to polymer science is “metathesis polymerization” discovered by Grubbs and others. The book will cover various metathesis polymerization methods and implications in polymer industry.