Download or read book The Role of Aluminate in the Activation of Catalytic Systems for Ethylene Oligomerization written by Ahmed Alzamly and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The reaction mechanisms followed by ethylene polymerization and selective oligomerization (tri- and tetramerization) are conceptually very different, being a non-redox chain growth and a redox metallacycle ring expansion pathway respectively. With chromium being the metal of choice, metal oxidation states and the variation of ancillary ligand able to support specific metal oxidation states responsible for selective trimerization, tetramerization or nonselective oligomerization/polymerization were varied. In this research project we have explored a broad range of novel pyridine containing modified PN ligand scaffolds with the aim of probing the role of the pyridine donor substituent in stabilizing lower oxidation states and ultimately affecting the selectivity of the ethylene in the catalytic cycle. In this study, pyridine PNP pincer ligands in conjunction with chromium salts and alkylaluminium activators have been explored. Their catalytic activities toward ethylene oligomerization were rationalized through the isolation of different chromium-aluminate intermediates in different oxidation states during the catalytic reaction. Moreover, we explored other pyridine modification of NNP type ligand. Its anionic ligand shows a rare example of a Cr(II) hydride cluster which shows a high activity as a nonselective ethylene oligomerization catalyst. Finally, a cyclic PNPN type ligand was explored. The ligand enabled the isolation of a mix-valent Cr(I)/Cr(II) species which was found to be inactive toward ethylene oligomerization due to its geometric constraint.
Download or read book Study of the Factors Affecting the Selectivity of Catalytic Ethylene Oligomerization written by Khalid Albahily and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade, advances in ethylene oligomerization have witnessed explosive growth of interest from both commercial and academic standpoint, with chromium metal invariably being the metal of preference. A common feature in this literature was the extended long debate regarding the mechanism, metal oxidation states responsible for selectivity and the role of the ligand. This thesis work embarked on the isolation and characterization of new active intermediates called "single component catalysts" (or self activating) to address two important questions: (1) how the catalyst precursors re-arrange upon activation and (2) the real oxidation state of the activated species. Four different ligands systems have been examined for this purpose. The first part is a study on the NPIIIN ligand which can be described as a dynamic and non-spectator ligand. Upon aluminum alkyl activation, a series of single component chromium catalysts for selective ethylene oligomerization and polymerization have been isolated, fully characterized and tested. New selective single component chromium(I) catalysts have also been isolated and tested positively for ethylene trimerization. The second part includes a new series of chromium complexes based on the NPVN ligand. This ligands enabled to obtain the first polymer-free extremely active catalytic system. In both NPN ligand systems, a new activation pathway was discovered by using vinyl Grignard reagent [(CH2=CH)MgCl] as activator and/or reducing agent. The third part explores new modified pyrrole-chromium complexes which were found to be highly active and selective ethylene trimerization catalysts. This part was a continuation of previous work from our lab to complete the mechanistic picture of this highly successful pyrrole-chromium catalyst independently commercialized by Phillips-Chevron and Mitsubishi. Interestingly upon aluminum alkyl treatment, the first example of a Schrock-type chromium ethylidene complex has been isolated and characterized and found to be a potent catalyst for selective ethylene trimerization. Finally, the other ligands introduced in this thesis are new systems called pyridine-SNS and Si-SNS that introduce some modification to the known commercial SNS catalyst (Sasol technology). The introduction of a pyridine ring or a silyl unit in the ligand scaffold has allowed to understand the mechanism of action of this remarkable system.
Download or read book The Challenge of Selectivity in Ethylene Oligomerization written by Indira Thapa and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Activation Of Alkenes And Alkynes written by M.M. Taqui Khan and published by Academic Press. This book was released on 1974-01-28 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Band 2.
Download or read book Activation Of Alkenes And Alkynes written by M.M. Taqui Khan and published by Elsevier. This book was released on 2012-12-02 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Homogeneous Catalysis by Metal Complexes, Volume II: Activation of Alkenes and Alkynes reviews and systematizes the chemistry of metal ion activation of alkenes and alkynes. The book presents the migration of ? bonds; the oxo reaction; and the hydrosilation of alkenes and alkynes. The text also covers topics on the oxidation of alkenes and alkynes, as well as the multiple insertion reactions of alkenes and alkynes.
Download or read book Olefin Polymerization written by Walter Kaminsky and published by Wiley-VCH. This book was released on 2006-08-18 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: With an enormous velocity, olefin polymerization has expanded to one of the most significant fields in polymers since the first industrial use about 50 years ago. In 2005, 100 million tons of polyolefins were produced - the biggest part was catalyzed by metallorganic compounds. The Hamburg Macromolecular Symposium 2005 with the title "Olefin Polymerization" involved topics such as new catalysts and cocatalysts, kinetics, mechanism and polymer reaction engineering, synthesis of special polymers, and characterization of polyolefins. The conference combined scientists from different disciplines to discuss latest research results of polymers and to offer each other the possibility of cooperation. This is reflected in this volume, which contains invited lectures and selected posters presented at the symposium.
Download or read book Oligomerization of Chemical and Biological Compounds written by Claire Lesieur and published by BoD – Books on Demand. This book was released on 2014-06-18 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many thanks to the authors for high quality chapters and to the referees for helping improve the manuscripts. The book is interdisciplinary, it covers fields from organic chemistry to mathematics, and raises different aspects of oligomerization. It is a great source of information as every chapter introduces general knowledge and deep details. Mixing communities is to instigate novel ideas and hopefully help looking at oligomerization with new eyes.
Download or read book Oligomer Technology and Applications written by Uglea and published by CRC Press. This book was released on 1998-01-05 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt: Details laboratory and industrial synthesis and applications of oligomers-suggesting practical solutions to the on-the-job problems as well as exploring processing devices and techniques for industrial-scale production of new oligomer types.
Download or read book Catalysis by Polymers written by E. A. Bekturov and published by John Wiley & Sons. This book was released on 2008-09-26 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aspects of Homogeneous Catalysis written by R. Ugo and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Transition Metal Polymerization Catalysts written by Ray Hoff and published by John Wiley & Sons. This book was released on 2018-04-20 with total page 895 pages. Available in PDF, EPUB and Kindle. Book excerpt: Including recent advances and historically important catalysts, this book overviews methods for developing and applying polymerization catalysts – dealing with polymerization catalysts that afford commercially acceptable high yields of polymer with respect to catalyst mass or productivity. • Contains the valuable data needed to reproduce syntheses or use the catalyst for new applications • Offers a guide to the design and synthesis of catalysts, and their applications in synthesis of polymers • Includes the information essential for choosing the appropriate reactions to maximize yield of polymer synthesized • Presents new chapters on vanadium catalysts, Ziegler catalysts, laboratory homopolymerization, and copolymerization
Download or read book Control of Polymerization Reactors written by Joseph Schork and published by CRC Press. This book was released on 1993-03-09 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference and text provides an in-depth description of developments in control techniques and their application to polymerization reactors and offers important introductory background information on polymerization reaction engineering.;Discussing modelling, identification, linear, nonlinear and multivariable schemes, Control of Polymerization Reactors: presents all available techniques that can be used to control reactors properly for optimal performance; shows how to manipulate pivotal variables that affect reactor control; examines methods for deriving dynamic process models to improve reactor efficiency; reviews reactor control problems and points out end-use properties; supplies methods for measuring process variables, and ways to estimate variables that can't be measured; and explains how single-input, single-output (SISO) strategies can be effectively used for control.;Filled with illustrative examples to clarify concepts, including more than 730 figures, tables and equations, Control of Polymerization Reactors is intended for use as a reference for chemical, process development, process design, research and development, control systems, and polymer engineers; and polymer chemists and physicists; as well as a text for upper-level undergraduate and graduate students in polymerization reactor control courses.
Download or read book Handbook of Transition Metal Polymerization Catalysts written by Ray Hoff and published by John Wiley & Sons. This book was released on 2018-04-20 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: Including recent advances and historically important catalysts, this book overviews methods for developing and applying polymerization catalysts – dealing with polymerization catalysts that afford commercially acceptable high yields of polymer with respect to catalyst mass or productivity. • Contains the valuable data needed to reproduce syntheses or use the catalyst for new applications • Offers a guide to the design and synthesis of catalysts, and their applications in synthesis of polymers • Includes the information essential for choosing the appropriate reactions to maximize yield of polymer synthesized • Presents new chapters on vanadium catalysts, Ziegler catalysts, laboratory homopolymerization, and copolymerization
Download or read book Activation of Small Molecules written by William B. Tolman and published by John Wiley & Sons. This book was released on 2006-12-13 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first to combine both the bioinorganic and the organometallic view, this handbook provides all the necessary knowledge in one convenient volume. Alongside a look at CO2 and N2 reduction, the authors discuss O2, NO and N2O binding and reduction, activation of H2 and the oxidation catalysis of O2. Edited by the highly renowned William Tolman, who has won several awards for his research in the field.
Download or read book Iron Catalysis II written by Eike Bauer and published by Springer. This book was released on 2015-07-23 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Organometallic Chemistry presents critical overviews of research results in organometallic chemistry. As our understanding of organometallic structure, properties and mechanisms increases, new ways are opened for the design of organometallic compounds and reactions tailored to the needs of such diverse areas as organic synthesis, medical research, biology and materials science. Thus the scope of coverage includes a broad range of topics of pure and applied organometallic chemistry, where new breakthroughs are being achieved that are of significance to a larger scientific audience. The individual volumes of Topics in Organometallic Chemistry are thematic. Review articles are generally invited by the volume editors.
Download or read book Catalysis written by J. J. Spivey and published by Royal Society of Chemistry. This book was released on 1999 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalysis will be of interest to anyone working in academia and industry that needs an up-to-date critical analysis and summary of catalysis research and applications.
Download or read book Journal of Organic Chemistry of the USSR written by and published by . This book was released on 1985 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:
