Download or read book A Cobalt Complex of Bis Methylthioether Pyridine Catalyst for Hydrogen Evolution from Water written by chunli wang and published by . This book was released on 2020 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new cobalt-based catalyst, [(btep)CoBr 2 ] is produced by the reaction of CoBr 2 and bis(methylthioether)pyridine (btep), and its structure has been determined by X-ray crystallography. Our experiments suggest that this cobalt complex can used as a molecular catalyst for electrochemical and photochemical driven hydrogen evolution. As an electrocatalyst, this cobalt complex can provide 591.9 moles of hydrogen per mole of catalyst per hour (mol H 2 /mol catalyst/h) from a neutral water under an overpotential (OP) of 837.6 mV. As a co-catalyst, it was mixed with CdS nanorods (CdS NRs) as a photosensitizer, and ascorbic acid (H 2 A) as a sacrificial electron donor, and [(btep)CoBr 2 ] can provide 9326.4 mol H 2 per mole of catalyst during 40 h irradiation. The highest apparent quantum yield (AQY) is ~25.5%. The catalytic mechanism for H 2 production is investigated by several measurements and analysis.
Download or read book Nickel and Cobalt Bis imino pyridine Complexes as Catalysts for the Hydrogen Evolution Reaction written by Bing Jiang and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: El subministrament d'energia sostenible és un desafiament crític que enfronta la humanitat. La dependència dels combustibles fòssils ha despertat l'interès en el desenvolupament de fonts d'energia lliures de carboni, entre les quals el dihidrogen que té una alta densitat d'energia seria un dels més prometedors sempre que es generi a partir d'alternatives renovables. En aquest context, dissociar l'aigua per produir hidrogen com a combustible és de gran interès i, per tant, s'estan desenvolupant una gran quantitat de catalitzadors per accelerar la velocitat d'aquesta reacció, preferiblement obtinguts a partir de metalls de transició abundants. Amb l'objectiu d'optimitzar l'economia de l'àtom de metall i facilitar l'anàlisi mecanístic, els complexos moleculars són una bona opció com a catalitzadors homogenis. En aquest tipus de compostos, els centres metal·lics que generalment es requereixen poden accedir a múltiples estats d'oxidació, de vegades a través d'intermedis de tipus metall-hidrur. No obstant això, el disseny de catalitzadors per a la reacció d'evolució de l'hidrogen (HER) inclou també una família de complexos amb lligands no innocents que poden operar com un reservori d'electrons i / o un lloc de protonació. El primer capítol d'aquesta tesi doctoral introdueix la necessitat i les tècniques per a la producció d'hidrogen per recolzar la demanda d'energia, incloent els electrocatalitzadors per HER basats en els metalls no nobles, níquel i cobalt. El segon capítol descriu els objectius d'aquesta Tesi, és a dir, la síntesi i caracterització dels lligands basats en diiminpiridina (PDI), actius en redox, juntament amb els complexos de níquel i cobalt obtingut a partir d'aquests lligands. Es presenten també com a objectius la seva avaluació electrocatalítica en HER així com la descripció dels processos des del punt de vista mecanístic. El tercer capítol presenta la preparació d'un conjunt de lligands PDI pentadentats, juntament amb la síntesi i caracterització completa de complexos de Ni(II) de hexacoordinats [Ni(Ph2PPrPDI)(Cl)](Cl) (1(Cl)) i [Ni(Ph2PPrPDI)(p)Cl)(Cl)](Cl) (2(Cl)). La ubicació dels electrons després de la reducció electroquímica d'1(Cl) es va examinar mitjançant càlculs de la teoria del funcional de la densitat (DFT) juntament amb la ressonància paramagnètica electrònica (EPR), la qual cosa va mostrar que la primera reducció d'un electró es produeix en el metall i la segona en el lligand. Es van estudiar també les propietats redox i catalítiques d'ambdós complexos. D'una banda, es va observar un potencial redox més positiu i, per tant, un sobrepotencial més baix per a 2(Cl), el que indica que la presència del substituent electroatraient Cl al lligand PDI millora l'activitat electrocatalítica. D'altra banda, 1(Cl) és més actiu per al HER en termes de TOF i constant de velocitat. Els estudis d'estabilitat a curt termini per a 1(Cl) i 2(Cl) en condicions de HER per CV indiquen que la catàlisi és homogènia sense descomposició, mentre que l'estabilitat a llarg termini analitzada per electròlisi potencial controlada mostra la generació d'una nova espècie transitòria que pot desencadenar la reacció d'oxidació d'hidrogen i al seu torn reduir el sobrepotencial per a la HER. El quart capítol s'enfoca en la síntesi i caracterització de complexos de Co coordinats de cinc amb els lligands aplicats en el tercer capítol ([CoI(Ph2PPrPDI](BF4), 3(BF4) i [CoI(Ph2PPrPDI(p)Cl](BF4), 4(BF4)). Les dades de l'electroquímica mostren que aquests complexos són actius per a la HER en medi orgànic, passant després de la reacció amb protons per espècies d'hidrur de Co(III) que es van identificar mitjançant espectroscòpia UV-vis i RMN. Sobre la base de l'espectroscòpia RMN, el compost de Co(I) inicial es va recuperar després d'un cicle de reacció catalític, el que demostra un mecanisme homolític per HER. Finalment, el cinquè capítol enumera les conclusions més rellevants extretes del treball realitzat.
Download or read book Preparing and Characterizing Bis imino pyridine Complexes of Nickel Iron and Cobalt for Electrocatalytic Hydrogen Evolution written by Samuel J. Underwood and published by . This book was released on 2016 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanistic Studies of Hydrogen Evolution in Aqueous Solution Catalyzed by a Tertpyridine amine Cobalt Complex written by and published by . This book was released on 2015 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CO2 Hydrogenation Catalysis written by Yuichiro Himeda and published by John Wiley & Sons. This book was released on 2021-06-28 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: A guide to the effective catalysts and latest advances in CO2 conversion in chemicals and fuels Carbon dioxide hydrogenation is one of the most promising and economic techniques to utilize CO2 emissions to produce value-added chemicals. With contributions from an international team of experts on the topic, CO2 Hydrogenation Catalysis offers a comprehensive review of the most recent developments in the catalytic hydrogenation of carbon dioxide to formic acid/formate, methanol, methane, and C2+ products. The book explores the electroreduction of carbon dioxide and contains an overview on hydrogen production from formic acid and methanol. With a practical review of the advances and challenges in future CO2 hydrogenation research, the book provides an important guide for researchers in academia and industry working in the field of catalysis, organometallic chemistry, green and sustainable chemistry, as well as energy conversion and storage. This important book: Offers a unique review of effective catalysts and the latest advances in CO2 conversion Explores how to utilize CO2 emissions to produce value-added chemicals and fuels such as methanol, olefins, gasoline, aromatics Includes the latest research in homogeneous and heterogeneous catalysis as well as electrocatalysis Highlights advances and challenges for future investigation Written for chemists, catalytic chemists, electrochemists, chemists in industry, and chemical engineers, CO2 Hydrogenation Catalysis offers a comprehensive resource to understanding how CO2 emissions can create value-added chemicals.
Download or read book Applications of Transition Metal Catalysis in Drug Discovery and Development written by Matthew L. Crawley and published by John Wiley & Sons. This book was released on 2012-05-14 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the drug discovery and development applications of transition metal catalyzed processes, which can efficiently create preclinical and clinical drug candidates as well as marketed drugs. The authors pay particular attention to the challenges of transitioning academically-developed reactions into scalable industrial processes. Additionally, the book lays the groundwork for how continued development of transition metal catalyzed processes can deliver new drug candidates. This work provides a unique perspective on the applications of transition metal catalysis in drug discovery and development – it is a guide, a historical prospective, a practical compendium, and a source of future direction for the field.
Download or read book Non Noble Metal Catalysis written by Robertus J. M. Klein Gebbink and published by John Wiley & Sons. This book was released on 2019-04-29 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: An expert overview of current research, applications, and economic and environmental advantages The study and development of new homogeneous catalysts based on first-row metals (Mn, Fe, Co, Ni, and Cu) has grown significantly due to the economic and environmental advantages that non-noble metals present. Base metals offer reduced cost, greater supply, and lower toxicity levels than noble metals?enabling greater opportunity for scientific investigation and increased development of practical applications. Non-Noble Metal Catalysis provides an authoritative survey of the field, from fundamental concepts and computational methods to industrial applications and reaction classes. Recognized experts in organometallic chemistry and homogeneous catalysis, the authors present a comprehensive overview of the conceptual and practical aspects of non-noble metal catalysts. Examination of topics including non-innocent ligands, proton-coupled electron transfer, and multi-nuclear complexes provide essential background information, while areas such as kinetic lability and lifetimes of intermediates reflect current research and shifting trends in the field. This timely book demonstrates the efficacy of base metal catalysts in the pharmaceutical, fine-chemical, and agrochemical industries, addressing both environmental and economic concerns. Providing essential conceptual and practical exploration, this valuable resource: -Illustrates how unravelling new reactivity patterns can lead to new catalysts and new applications -Highlights the multiple advantages of using non-noble metals in homogenous catalysis -Demonstrates how the availability of non-noble metal catalysis reduces costs and leads to immense savings for the chemical industry -Reveals how non-noble metal catalysis are more sustainable than noble metals such as palladium or platinum Non-Noble Metal Catalysis: Molecular Approaches and Reactions is an indispensable source of up-to-date information for catalytic chemists, organic chemists, industrial chemists, organometallic chemists, and those seeking to broaden their knowledge of catalytic chemistry.
Download or read book Practical Synthetic Organic Chemistry written by Stéphane Caron and published by John Wiley & Sons. This book was released on 2020-02-05 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a hands-on guide for the organic chemist. Focusing on the most reliable and useful reactions, the chapter authors provide the information necessary for a chemist to strategically plan a synthesis, as well as repeat the procedures in the laboratory. Consolidates all the key advances/concepts in one book, covering the most important reactions in organic chemistry, including substitutions, additions, eliminations, rearrangements, oxidations, reductions Highlights the most important reactions, addressing basic principles, advantages/disadvantages of the methodology, mechanism, and techniques for achieving laboratory success Features new content on recent advances in CH activation, photoredox and electrochemistry, continuous chemistry, and application of biocatalysis in synthesis Revamps chapters to include new and additional examples of chemistry that have been demonstrated at a practical scale
Download or read book Supported Metal Complexes written by F.R. Hartley and published by Springer Science & Business Media. This book was released on 1985-11-30 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is now IS years since the first patents in polymer supported metal complex catalysts were taken out. In the early days ion-exchange resins were used to support ionic metal complexes. Soon covalent links were developed, and after an initially slow start there was a period of explosive growth in the mid to late 1970s during which virtually every homogeneous metal complex catalyst ever reported was also studied bound to a support. Both polymers and inorganic oxides were studied as supports, although the great preponderance of workers studied polymeric supports, and of these polystyrene was by far the commonest used. This period served to show that by very careful design polymer-supported metal complex catalysts could have specific advantages over homogeneous metal complex catalysts. However the subject was a complicated one. Merely immobilising a successful metal complex catalyst to a functionalised support rarely yielded other than an inferior version of the catalyst. Amongst the many discouraging results of the 1970s, there were more than enough results that were sufficiently encouraging to demonstrate that, by careful design, supported metal complex catalysts could be prepared in which both the metal complex and the support combined together to produce an active catalyst which, due to the combination of support and complex, had advantages of activity, selectivity and specificity not found in homogeneous catalysts. Thus a new generation of catalysts was being developed.
Download or read book Advances in Spectroscopy Molecules to Materials written by Dheeraj Kumar Singh and published by Springer. This book was released on 2020-10-26 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents and discusses recent developments in the broad field of spectroscopy, providing the reader with an updated overview. The main objective is to introduce them to recent innovations and current trends in spectroscopy applied to molecules and materials. The book also brings together experimentalists and theoreticians to highlight the multidimensional aspects of spectroscopy and discuss the latest issues. Accordingly, it provides insights not only into the general goals of spectroscopy, but also into how the various spectroscopic techniques represent a toolbox that can be used to gain a more detailed understanding of molecular systems and complex chemical problems. Besides technical aspects, basic theoretical interpretations of spectroscopic results are also presented. The spectroscopy techniques discussed include UV-visible absorption spectroscopy, Raman spectroscopy, IR absorption spectroscopy, fluorescence spectroscopy, and time-resolved spectroscopy. In turn, basic tools like lasers and theoretical modeling approaches are also presented. Lastly, applications for the characterization of fundamental properties of molecules (environmental aspects, biomolecules, pharmaceutical drugs, hazardous molecules, etc.) and materials (nanomaterials, nuclear chemistry materials, biomaterials, etc.) are discussed. Given its scope, the book offers a valuable resource for researchers from various branches of science, and presents new techniques that can be applied to their specific problems.
Download or read book Extraction of Metals from Soils and Waters written by D. M. Roundhill and published by Springer Science & Business Media. This book was released on 2001-12-31 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extractions of Metals from Soils and Waters represents a new emphasis in the series Modern Inorganic Chemistry, namely the impact inorganic chemistry can have on the environment. Also, this is the first volume ever to introduce the reader to all aspects of heavy metal extraction. While the primary emphasis is on complexation chemistry, attention is also paid to phase transfer aspects. Particular methods of note include electrokinetics, phytoremediation, and sensors. Aimed primarily at chemists, this book will also appeal to engineers, plant biochemists, environmental health specialists, and practitioners or students of environmental law.
Download or read book Chemistry and Technology of Flavours and Fragrances written by David Rowe and published by John Wiley & Sons. This book was released on 2009-02-12 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern flavours and fragrances are complex formulated products,containing blends of aroma compounds with auxiliary materials,enabling desirable flavours or fragrances to be added to a hugerange of products. From the identification and synthesis ofmaterials such as cinnamaldehyde and vanillin in the 19th Centuryto the current application of advanced analytical techniques foridentification of trace aroma compounds present in naturalmaterials, the flavour and fragrance industry has developed as akey part of the worldwide specialty chemicals industry. With contributions mainly coming from industry based experts,Chemistry & Technology of Flavours and Fragrancesprovides a detailed overview of the synthesis, chemistry andapplication technology of the major classes aroma compounds. Withseparate chapters covering important technical aspects such as thestability of aroma compounds, structure – odour relationshipsand identification of aroma compounds, this book will be essentialreading for both experienced and graduate level entrants to theflavour & fragrance industry. It will also serve as animportant introduction to the subject for chemists andtechnologists in those industries that use flavours and fragrances,eg food, cosmetics & toiletries, and household products. David Rowe is Technical Manager at De Monchy Aromatics Ltd.,Poole UK
Download or read book Handbook of Photochemistry written by Marco Montalti and published by CRC Press. This book was released on 2006-02-21 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the publication of the second edition of this handbook in 1993, the field of photochemical sciences has continued to expand across several disciplines including organic, inorganic, physical, analytical, and biological chemistries, and, most recently, nanosciences. Emphasizing the important role light-induced processes play in all of these fie
Download or read book Vanadium Catalysis written by Manas Sutradhar and published by Royal Society of Chemistry. This book was released on 2020-11-05 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vanadium is one of the more abundant elements in the Earth’s crust and exhibits a wide range of oxidation states in its compounds making it potentially a more sustainable and more economical choice as a catalyst than the noble metals. A wide variety of reactions have been found to be catalysed by homogeneous, supported and heterogeneous vanadium complexes and the number of applications is growing fast. Bringing together the research on the catalytic uses of this element into one essential resource, including theoretical perspectives on proposed mechanisms for vanadium catalysis and an overview of its relevance in biological processes, this book is a useful reference for industrial and academic chemists alike.
Download or read book Small Molecule Drug Discovery written by Andrea Trabocchi and published by Elsevier. This book was released on 2019-11-23 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small Molecule Drug Discovery: Methods, Molecules and Applications presents the methods used to identify bioactive small molecules, synthetic strategies and techniques to produce novel chemical entities and small molecule libraries, chemoinformatics to characterize and enumerate chemical libraries, and screening methods, including biophysical techniques, virtual screening and phenotypic screening. The second part of the book gives an overview of privileged cyclic small molecules and major classes of natural product-derived small molecules, including carbohydrate-derived compounds, peptides and peptidomimetics, and alkaloid-inspired compounds. The last section comprises an exciting collection of selected case studies on drug discovery enabled by small molecules in the fields of cancer research, CNS diseases and infectious diseases. The discovery of novel molecular entities capable of specific interactions represents a significant challenge in early drug discovery. Small molecules are low molecular weight organic compounds that include natural products and metabolites, as well as drugs and other xenobiotics. When the biological target is well defined and understood, the rational design of small molecule ligands is possible. Alternatively, small molecule libraries are being used for unbiased assays for complex diseases where a target is unknown or multiple factors contribute to a disease pathology. - Outlines modern concepts and synthetic strategies underlying the building of small molecules and their chemical libraries useful for drug discovery - Provides modern biophysical methods to screening small molecule libraries, including high-throughput screening, small molecule microarrays, phenotypic screening and chemical genetics - Presents the most advanced chemoinformatics tools to characterize the structural features of small molecule libraries in terms of chemical diversity and complexity, also including the application of virtual screening approaches - Gives an overview of structural features and classification of natural product-derived small molecules, including carbohydrate derivatives, peptides and peptidomimetics, and alkaloid-inspired small molecules
Download or read book Radiochemistry and Nuclear Chemistry written by Gregory Choppin and published by Butterworth-Heinemann. This book was released on 2002 with total page 726 pages. Available in PDF, EPUB and Kindle. Book excerpt: Origin of Nuclear Science; Nuclei, Isotopes and Isotope Separation; Nuclear Mass and Stability; Unstable Nuclei and Radioactive Decay; Radionuclides in Nature; Absorption of Nuclear Radiation; Radiation Effects on Matter; Detection and Measurement Techniques; Uses of Radioactive Tracers; Cosmic Radiation and Elementary Particles; Nuclear Structure; Energetics of Nuclear Reactions; Particle Accelerators; Mechanics and Models of Nuclear Reactions; Production of Radionuclides; The Transuranium Elements; Thermonuclear Reactions: the Beginning and the Future; Radiation Biology and Radiation Protection; Principles of Nuclear Power; Nuclear Power Reactors; Nuclear Fuel Cycle; Behavior of Radionuclides in the Environment; Appendices; Solvent Extraction Separations; Answers to Exercises; Isotope Chart; Periodic Table of the Elements; Quantities and Units; Fundamental Constants; Energy Conversion Factors; Element and Nuclide Index; Subject Index.
Download or read book Inorganic Electronic Spectroscopy written by A. B. P. Lever and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
