Download or read book Fischer and N heterocyclic Carbene Complexes of Tungsten 0 written by René Pretorius and published by . This book was released on 2012 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis of novel Fischer and N-heterocyclic tungsten(0) carbene complexes was endeavoured in this study and resulted in the synthesis, isolation and characterisation of eighteen new complexes. Sixteen novel Fischer carbene complexes were synthesised. In these complexes, both carbene ligand substituents were varied. Ethoxy as well as amino heteroatom substituents were used. Heteroaryl compounds thiophene and furan were employed as the second substituents on the carbene ligand. Complexes with combinations of these different substituents were synthesised and investigated to assess the influence the various substituents of the carbene ligand may have on the carbene complex itself. In addition, the metal ligand sphere was altered by substitution of one or two carbonyl ligands for either an amine or a phosphine ligand/s. These substitutions resulted in the formation of metal pentacarbonyl, metal tetracarbonyl as well as metal tricarbonyl systems. The complexes were successfully characterised by means of NMR and IR spectroscopy, and in selected cases X-ray diffraction and mass spectrometry. Synthesis of N-heterocyclic carbene complexes derived from isopropyl and mesityl imidazolium chlorides was attempted. The products were obtained in crude form, but could not be isolated due to decomposition during purification. Two novel decomposition products, which point towards a unique decomposition route, were isolated. Theoretical models of both the novel Fischer carbene complexes and the N-heterocyclic carbene complexes were calculated. This allowed for identification of infrared modes observed in experimental data. Furthermore, the HOMO and LUMO distributions and the HOMO-LUMO energy gaps were calculated, along with electrostatic potential maps. In all the Fischer carbene complexes the HOMOs were located on the metal centre and the LUMOs on the carbene ligand. In contrast, the HOMO and the LUMO were both located on the metal centre for the N-heterocyclic carbenes. The HOMO-LUMO energy gap decreased as follows: NHC complexes > Amino Fischer carbene complexes > Ethoxy Fischer carbene complexes Lastly, in all the complexes studied, the electrostatic potential maps indicated that the highest amount of electron density was found on the carbonyl ligands of these complexes. Both experimental and theoretical data indicated marked differences in the various classes of compounds, suggesting that these complexes would not only have different reactivities but also be suited to different applications. Experimental studies on reactivity and applications are thus future avenues of study which are made available from these results.
Download or read book Advances in Organometallic Chemistry written by Pedro J. Perez and published by Academic Press. This book was released on 2022-04-20 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Organometallic Chemistry, Volume 77, the latest release in this longstanding serial, is known for its comprehensive coverage of topics in organometallic synthesis, reactions, mechanisms, homogeneous catalysis, and more. It is ideal for a wide range of researchers involved in organometallic chemistry, with this updated release including chapters on Organometallic-like reactivity of group 10 metal-heteroatom sigma bonds, Organometallic interactions between metal nanoparticles and carbon-based molecules: a surface reactivity rationale, Group VI Allenylidene Complexes, and more. Contains contributions from leading authorities in the field of organometallic chemistry Covers topics in organometallic synthesis, reactions, mechanisms, homogeneous catalysis, and more Informs and updates readers on the latest developments in the field Carefully edited to provide easy-to-read material
Download or read book The Organometallic Chemistry of N heterocyclic Carbenes written by Han Vinh Huynh and published by John Wiley & Sons. This book was released on 2017-04-17 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Organometallic Chemistry of N-heterocyclic Carbenes describes various aspects of N-heterocyclic Carbenes (NHCs) and their transition metal complexes at an entry level suitable for advanced undergraduate students and above. The book starts with a historical overview on the quest for carbenes and their complexes. Subsequently, unique properties, reactivities and nomenclature of the four classical NHCs derived from imidazoline, imidazole, benzimidazole and 1,2,4-triazole are elaborated. General and historically relevant synthetic aspects for NHCs, their precursors and complexes are then explained. The book continues with coverage on the preparation and characteristics of selected NHC complexes containing the most common metals in this area, i.e. Ni, Pd, Pt, Ag, Cu, Au, Ru, Rh and Ir. The book concludes with an overview and outlook on the development of various non-classical NHCs beyond the four classical types. Topics covered include: Stabilization, dimerization and decomposition of NHCs Stereoelectronic properties of NHCs and their evaluation Diversity of NHCs Isomers of NHC complexes and their identification NMR spectroscopic signatures of NHC complexes normal, abnormal and mesoionic NHCs The Organometallic Chemistry of N-heterocyclic Carbenes is an essential resource for all students and researchers interested in this increasingly important and popular field of research.
Download or read book Novel Strategies for the Synthesis of Tungsten VI and Molybdenum VI Imido Oxo Alkylidene NHC Complexes and Their Application in Ring Opening Metathesis Polymerization written by Janis Musso and published by Cuvillier Verlag. This book was released on 2022-05-12 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, the synthesis of neutral and cationic group(VI) imido/oxo alkylidene N-heterocyclic carbene (NHC) complexes that tolerate protic functional groups and aldehydes was reported. Unprecedented turnover numbers of up to 1.2 million were found for their silica-supported representatives. Some group(VI) alkylidene NHC complexes even display stability towards moisture and air. Coordination of the NHC to tungsten imido bistriflate precursor complexes, however, can lead to undesired side reactions. This work consequently aimed at the development of novel, more efficient routes to neutral and cationic tungsten imido/oxo alkylidene NHC complexes. In addition, some molybdenum imido alkylidene NHC complexes were targeted. Thereby, the scope of synthetically accessible complexes was broadened and, subsequently, their reactivity in ring-opening metathesis polymerization (ROMP) was probed. Those complexes were used as thermally latent initiators for the ROMP of dicyclopentadiene. Precise determination of the onset temperature of polymerization was achieved via monitoring with differential scanning calorimetry. Furthermore, the selectivity of novel complexes was tested for the formation of stereoregular polymers through ROMP of enantiomerically pure norbornene derivatives, which allowed for the synthesis of up to 98% trans-isotactic or cis-syndiotactic polymers depending on the steric demand of the imido and the alkoxide ligand.
Download or read book N heterocyclic Carbenes written by Silvia Díez-González and published by Royal Society of Chemistry. This book was released on 2011 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last fifteen years, N-heterocyclic carbenes (NHCs) have mostly been used as ancillary ligands for the preparation of transition metal-based catalysts. Compared to phosphorus-containing ligands, NHCs tend to bind more strongly to metal centres, avoiding the necessity for the use of excess ligand in catalytic reactions. The corresponding complexes are often less sensitive to air and moisture, and have proven remarkably resistant to oxidation. Recent developments in catalysis applications have been facilitated by the availability of carbenes stable enough to be bottled, particularly for their use as organocatalysts. This book shows how N-heterocyclic carbenes can be useful in various fields of chemistry and not merely laboratory curiosities or simple phosphine mimics. NHCs are best known for their contribution to ruthenium and palladium-catalysed reactions but the scope of this book is much broader. The synthesis of NHC ligands and their corresponding metal complexes are covered in depth. Moreover, the biological activity of NHC-containing complexes, as well as an overview of their theoretical aspects are included. Such metal species are further examined, not only in terms of their catalytic applications, but also of their stereoelectronic parameters and reactivity/stability. Finally, special attention is given to the hot topic of organocatalysis. The book will be of interest to postgraduates, academic researchers and those working in industry.
Download or read book The Organometallic Chemistry of the Transition Metals written by Robert H. Crabtree and published by John Wiley & Sons. This book was released on 2011-09-20 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: "One impressive and compressive book. . . . This review would have to be book size to do full justice to all the insights in this volume." —Journal of Metals Online Fully updated and expanded to reflect recent advances, this Fifth Edition of the classic text provides students and professional chemists with a comprehensive introduction to the principles and general properties of organometallic compounds, as well as including practical information on reaction mechanisms and detailed descriptions of contemporary applications. With increased focus on organic synthesis applications, nanoparticle science, and green chemistry, the Fifth Edition brings this vital resource up to date. New to the Fifth Edition: Chapters have been updated with relevant examples in the field, modern trends, and new applications; the organic applications chapter has been completely rewritten New end-of-chapter problems, along with their solutions Coverage enhanced with developments in nanoparticle science Increased focus on green chemistry An unparalleled pedagogic resource as well as a valuable working reference for professional chemists, with comprehensive coverage and up-to-date information, students and researchers in organic and organometallic chemistry will turn to The Organometallic Chemistry of the Transition Metals, Fifth Edition for the critical information they need on organometallic compounds, their preparation, and their use in synthesis.
Download or read book Landmarks in Organo Transition Metal Chemistry written by Helmut Werner and published by Springer Science & Business Media. This book was released on 2008-12-16 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the discovery of ferrocene and the sandwich-type complexes, the development of organometallic chemistry took its course like an avalanche and became one of the scientific success stories of the second half of the twentieth century. Based on this development, the traditional boundaries between inorganic and organic chemistry gradually disappeared and a rebirth of the nowadays highly important field of homogeneous catalysis occurred. It is fair to say that despite the fact that the key discovery, which sparked it all off, was made more than 50 years ago, organometallic chemistry remains a young and lively discipline.
Download or read book N Heterocyclic Carbenes written by Silvia Diez-Gonzalez and published by Royal Society of Chemistry. This book was released on 2016-11-08 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: In less than 20 years N-heterocyclic carbenes (NHCs) have become well-established ancillary ligands for the preparation of transition metal-based catalysts. This is mainly due to the fact that NHCs tend to bind strongly to metal centres, avoiding the need of excess ligand in catalytic reactions. Also, NHC‒metal complexes are often insensitive to air and moisture, and have proven remarkably resistant to oxidation. This book showcases the wide variety of applications of NHCs in different chemistry fields beyond being simple phosphine mimics. This second edition has been updated throughout, and now includes a new chapter on NHC‒main group element complexes. It covers the synthesis of NHC ligands and their corresponding metal complexes, as well as their bonding and stereoelectronic properties and applications in catalysis. This is complemented by related topics such as organocatalysis and biologically active complexes. Written for organic and inorganic chemists, this book is ideal for postgraduates, researchers and industrialists.
Download or read book Multicomponent Reactions written by Raquel P. Herrera and published by John Wiley & Sons. This book was released on 2015-04-27 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: Addressing a dynamic aspect of organic chemistry, this book describes synthetic strategies and applications for multicomponent reactions – including key routes for synthesizing complex molecules. • Illustrates the crucial role and the important utility of multicomponent reactions (MCRs) to organic syntheses • Compiles novel and efficient synthetic multicomponent procedures to give readers a complete picture of this class of organic reactions • Helps readers to design efficient and practical transformations using multicomponent reaction strategies • Describes reaction background, applications to synthesize complex molecules and drugs, and reaction mechanisms
Download or read book The Effect of Remote Donor Substituents on the Properties of Alkoxy and Amino Fischer Carbene Complexes of Tungsten written by Nora-ann Weststrate and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Organometallic Chemistry written by and published by Academic Press. This book was released on 2017-06-08 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Organometallic Chemistry, Volume 67 contains authoritative review articles of worldwide known researchers on the field of organometallic chemistry, covering topics in organometallic synthesis, reactions, mechanisms, homogeneous catalysis, and more. Updates in this new volume include chapters on Group 6 Metal Fischer Carbene Complexes: Versatile Synthetic Building Blocks, Recent Advances in Transition-Metal-Catalyzed Cross-Coupling Reactions With Tosylhydrazones,Oxidative Functionalization of Late Transition Metal-Carbon Bond, and Biaryl Synthesis via C–H Bond Activation: Strategies and Methods. This book will benefit a wide range of researchers involved in organometallic chemistry, including those working on synthetic protocols, mechanistic studies and practical applications. Contains contributions from leading authorities in the field of organometallic chemistry Covers topics in organometallic synthesis, reactions, mechanisms, homogeneous catalysis, and more Informs and updates readers on all the latest developments in the field Carefully edited to provide easy-to-read material
Download or read book Stabilization and Reactivity of Zero valent Tungsten Nitrene Complexes written by Bruce A. Arndtsen and published by . This book was released on 1993 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Carbene Chemistry written by Guy Bertrand and published by CRC Press. This book was released on 2002-05-14 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highlights recent discoveries in the development of rapid kinetic techniques that allow for direct visualization and state-of-the-art computational methods.
Download or read book Organic Synthesis Using Transition Metals written by Roderick Bates and published by John Wiley & Sons. This book was released on 2012-04-30 with total page 469 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metals open up new opportunities for synthesis, because their means of bonding and their reaction mechanisms differ from those of the elements of the s and p blocks. In the last two decades the subject has mushroomed - established reactions are seeing both technical improvements and increasing numbers of applications, and new reactions are being developed. The practicality of the subject is demonstrated by the large number of publications coming from the process development laboratories of pharmaceutical companies, and its importance is underlined by the fact that three Nobel prizes have been awarded for discoveries in this field in the 21st Century already. Organic Synthesis Using Transition Metals, 2nd Edition considers the ways in which transition metals, as catalysts and reagents, can be used in organic synthesis, both for pharmaceutical compounds and for natural products. It concentrates on the bond-forming reactions that set transition metal chemistry apart from "classical" organic chemistry. Each chapter is extensively referenced and provides a convenient point of entry to the research literature. Topics covered include: introduction to transition metals in organic synthesis coupling reactions C-H activation carbonylative coupling reactions alkene and alkyne insertion reactions electrophilic alkene and alkyne complexes reactions of alkyne complexes carbene complexes h3- or p-allyl -allyl complexes diene, dienyl and arene complexes cycloaddition and cycloisomerisation reactions For this second edition the text has been extensively revised and expanded to reflect the significant improvements and advances in the field since the first edition, as well as the large number of new transition metal-catalysed processes that have come to prominence in the last 10 years – for example the extraordinary progress in coupling reactions using “designer” ligands, catalysis using gold complexes, new opportunities arising from metathesis chemistry, and C-H activation – without neglecting the well established chemistry of metals such as palladium. Organic Synthesis Using Transition Metals, 2nd Edition will find a place on the bookshelves of advanced undergraduates and postgraduates working in organic synthesis, catalysis, medicinal chemistry and drug discovery. It is also useful for practising researchers who want to refresh and enhance their knowledge of the field.
Download or read book Stereoselective Synthesis of Drugs and Natural Products written by Vasyl Andrushko and published by John Wiley & Sons. This book was released on 2013-08-16 with total page 1836 pages. Available in PDF, EPUB and Kindle. Book excerpt: Brings together the best tested and proven stereoselective synthetic methods Both the chemical and pharmaceutical industries are increasingly dependent on stereoselective synthetic methods and strategies for the generation of new chiral drugs and natural products that offer specific 3-D structures. With the publication of Stereoselective Synthesis of Drugs and Natural Products, researchers can turn to this comprehensive two-volume work to guide them through all the core methods for the synthesis of chiral drugs and natural products. Stereoselective Synthesis of Drugs and Natural Products features contributions from an international team of synthetic chemists and pharmaceutical and natural product researchers. These authors have reviewed the tremendous body of literature in the field in order to compile a set of reliable, tested, and proven methods alongside step-by-step guidance. This practical resource not only explores synthetic methodology, but also reaction mechanisms and applications in medicinal chemistry and drug discovery. The publication begins with an introductory chapter covering general principles and methodologies, nomenclature, and strategies of stereoselective synthesis. Next, it is divided into three parts: Part One: General Methods and Strategies Part Two: Stereoselective Synthesis by Bond Formation including C-C bond formation C-H bond formation C-O bond formation C-N bond formation Other C-heteroatom formation and other bond formation Part Three: Methods of Analysis and Chiral Separation References in every chapter serve as a gateway to the literature in the field. With this publication as their guide, chemists involved in the stereoselective synthesis of drugs and natural products now have a single, expertly edited source for all the methods they need.
Download or read book Lanthanides And Actinides The Synthesis Reactivity Properties And Applications written by Stephen T Liddle and published by World Scientific. This book was released on 2021-12-30 with total page 727 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Lanthanides and Actinides: Synthesis, Reactivity, Properties and Applications constitutes an introduction to and comprehensive coverage of f-block chemistry encompassing the following areas: periodicity, natural occurrence and extraction, separations, electronic structure, coordination chemistry, organometallic chemistry, small molecule activation, catalysis, organic synthesis applications, magnetism, spectroscopy, computation, materials, photonics, solar cell technology, biological imaging, and technological applications. Under these subject areas the book provides a broad but deep coverage, providing basic overviews as well as detailed chapters on specific areas.This book, targeted at academics, postgraduates and advanced undergraduates, will serve as an ideal introductory text and key reference work to the Lanthanides and Actinides.
Download or read book Issues in Chemistry and General Chemical Research 2012 Edition written by and published by ScholarlyEditions. This book was released on 2013-01-10 with total page 1539 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Chemistry and General Chemical Research: 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Chirality. The editors have built Issues in Chemistry and General Chemical Research: 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Chirality in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Chemistry and General Chemical Research: 2012 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.
