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Book Synthesis Characterization and Reactivity of Ni II Complexes Stabilized by an Intramolecular Hydrogen Bonding Network

Download or read book Synthesis Characterization and Reactivity of Ni II Complexes Stabilized by an Intramolecular Hydrogen Bonding Network written by Darla A. Powell-Jia and published by . This book was released on 2010 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metalloenzymes are able to perform a wide variety of difficult chemical transformations in a highly selective and efficient manner. The ability of metal complexes to perform a particular chemical reaction is dependant on the properties of the primary and secondary coordination environments. Development of transition metal complexes that catalyze the formation of organic compounds in a selective and highly efficient manner is of interest to synthetic chemists. Advancement in this area of research requires studies aimed at developing ligands that will give desirable properties upon binding to a metal ion. Using interactions present in biological systems, the ligands in this study have been developed to investigate the effects of the primary coordination sphere as well as hydrogen bonding interactions on complex formation as well as reactivity. Chapter 2 discusses the synthesis of terminal monomeric NiII-OH complexes with H41R. The hydroxo ligand is stabilized by two intramolecular hydrogen bonding interactions and the source of the hydroxo ligand was confirmed to be water. Attempts to deprotonate the NiII-OH complex to form a NiII-oxo complex were unsuccessful. Treating the NiII-OH complexes with KOtBu afforded the alkoxide substituted product. NiII-siloxide complexes were isolated upon reaction of NiII-OH with K[N(TMS)2]. Chapter 3 features the synthesis of a series of Ni(II) complexes with H2pmb, which contains two carboxyamido units appended from pyridine rings. Four Ni(II) complexes were synthesized and structurally characterized. It was determined that the carboxyamido groups either provided intramolecular H-bonds or the carbonyl oxygen can bind directly to the metal center. Chapter 4 explores the electrochemistry of the Ni(II) complexes characterized in Chapter 3. Based upon the observed reduction potentials, the reduction chemistry of [NiIIH2pmb(Cl)2] was explored. Further reactivity of the reduced species was also explored with dioxygen. Preliminary reactivity studies will also be discussed.

Book Catalysis from A to Z

Download or read book Catalysis from A to Z written by Boy Cornils and published by John Wiley & Sons. This book was released on 2020-01-13 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a complete and accessible A to Z collection of information on catalysis This updated and enlarged must-have edition of a classic book on catalysis explains the important terms of all aspects of the subject - including biocatalysis, homogeneous catalysis, heterogeneous catalysis - as well as the terms associated with it. It also looks at related topics like spectroscopy or analytical methods. Featuring 20% more content than the previous edition, it comprehensively covers the topic in a clear and concise manner, and includes abbreviations, brief biographic entries of important scientists who have worked in catalysis, trade names, important catalytic processes, named reactions, reactions, and other important keywords in the general field of catalysis. Written by more than 200 top scientists and with more than 15,000 entries on all aspects of catalysis, Catalysis from A to Z: A Concise Encyclopedia, 5th Edition is filled with figures, tables, cross-references, and references. It covers acids, ligands, catalytic reactions in organic synthesis, kinetics and thermodynamics of catalytic reactions, and catalyst labeling. The book also looks at theoretical backgrounds of catalytic reactions, industrial catalytic processes, autoclaves, colloids, nanomaterials, spectroscopically methods for catalyst analysis, and more. Provides all the knowledge scientists need to know about homogeneous, heterogeneous, and biochemical catalysis Includes more than 15,000 keywords in compact entries Newly updated and expanded edition of the bestselling classic Comprehensive, succinct, and easy to use Edited by an experienced team of top editors and authors with contributions from over 200 scientific experts Offers German and French translations of the keywords to help students and non-native English speakers Catalysis from A to Z: A Concise Encyclopedia is an ideal resource for every student, chemist, scientist, and engineer involved in catalytic chemistry, chemical engineering, biochemistry, organic chemistry, and more.

Book Synthesis and Characterization of Group VIII IX Transition Metal Complexes and Their Application in C H Bond Activation and Hydrogen Transformation

Download or read book Synthesis and Characterization of Group VIII IX Transition Metal Complexes and Their Application in C H Bond Activation and Hydrogen Transformation written by Hongmei Yuan and published by . This book was released on 2018 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: "A cobalt analogue of Cp*Co(PMe3)Me(OTf) (Cp* = 1, 2, 3, 4, 5 - pentamethylcyclopenta-dienyl, OTf = OSO2CF3), in Chapter 2, was attempted to be synthesized and studied for electrophilic C-H bond activation. Three new cobalt complexes Cp*Co(PMe3)(Me)2, Cp*Co(PMe3)(OTf)2 and Cp*Co(PMe3)(Me)(I) were synthesized. The 1H NMR spectrum showed a new material formed after mixing Cp*Co(PMe3)(Me)2 and Cp*Co(PMe3)(OTf)2 in 1:1 ratio. In Chapter 3, five carboxylate ligated iridium complexes (dmPhebox)Ir(O2CR)2(H2O) (R = -CH3(known compound), -CH2CH3, -CMe3, - CH2C6H5, -CH=CMe2) were designed and synthesized to understand the carboxylate ligand effects on the reactivity of the complex for alkane dehydrogenation. Results from the kinetic study showed that different R groups of the carboxylate iridium complexes can affect the reactivity with octane in the ??H elimination step. The rate constants for octane formation with different carboxylate ligands follow the order R = -CH=CMe2 > -CMe3 > -CH2CH3 > -CH3 > -CH2C6H5. In contrast, there is no significant effect of carboxylate ligand on the rate of the C-H activation step at 160 ʻC. These experimental results support the findings in the previously reported density functional theory (DFT) study of the (dmPhebox)Ir complex in alkane C-H activation. In Chapter 4,5 and 6, hydrogen transformation during the dehydrogenation and hydrogenation of N-heterocycles with a cobalt pincer catalyst, hydrogenation of alkenes with Fe(II) precursors, and hydrogenation of alcohols and dehydrogenation of ketones with a Cp*Rh(III) catalyst were investigated. The results of the acceptorless, reversible dehydrogenation and hydrogenation of N-heterocycles suggests a bifunctional dehydrogenation pathway and a non-bifunctional hydrogenation mechanism. The iron catalysts described in Chapter 5 operate via a metal-ligand cooperative pathway via a stepwise hydride transfer and then proton transfer mechanism. The Cp*Rh(III) catalysts in Chapter 6 decompose upon heating to give nanoparticles."--Pages xi-xii.

Book Synthesis and Characterization of Iridium Acetate Complexes for the Activation and Functionalization of C H Bonds

Download or read book Synthesis and Characterization of Iridium Acetate Complexes for the Activation and Functionalization of C H Bonds written by Daniel Anthony Frasco and published by . This book was released on 2015 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis and Characterization of Nickel thiolate Complexes as a Model of the Active Site of Ni Fe Hydrogenase Enzymes

Download or read book Synthesis and Characterization of Nickel thiolate Complexes as a Model of the Active Site of Ni Fe Hydrogenase Enzymes written by Dao Hinh Nguyen and published by . This book was released on 1997 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Nickel Catalysis and Coordination Chemistry

Download or read book Nickel Catalysis and Coordination Chemistry written by Yahya Albkuri and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Different metals and metal complexes have been used as catalysts in many industries such as commodity petrochemicals, fine and specialty chemicals, polymers, environmental services, agrochemicals and pharmaceuticals. Although these catalysts allow for increased reaction rates and selectivity, they can also be toxic, expensive and of limited supply (cf. Pt group metals). This has led researchers to the intensive study of first row metal catalysts, with nickel standing out as the most widely studied to date. As found for other first row metal catalysts, nickel's easy access to oxidation states 0-3 allows for a number of different one- and two-electron mechanisms and novel transformations. In Chapter 2 we use a phosphine-free, tridentate N,N,N ligand to generate an active catalyst for the C-N cross-coupling reaction of aryl halides with amines. The catalyst demonstrated excellent turnover numbers (up to 484) for the amination reactions that are proposed to proceed through a Ni(I)-Ni(III) cycle. In Chapter 3 we investigate the Ni coordination chemistry of a biomimetic SNS thiolate ligand. Protonation of the Ni bis(thiolate) complex, Ni(-SNS)2, removes one SNS ligand, affording crystals of a thiolate-bridged dimer dication, {[Ni(--SNS)]2}2+ that exhibits unique anionic tridentate ligand dynamics. Dissolving these crystals, even in weakly-coordinating solvents such as dichloromethane, gives a mixture of 'naked' Ni2+ and paramagnetic, trinuclear {[Ni(--SNS)2]2Ni}2+. Although this equilibrium lies far to the right (no diamagnetic dication visible in NMR), addition of ancillary ligands proceeds smoothly to provide several mono- and dinuclear Ni thiolate products, [Ni-SNS)L]n - potential bifunctional catalysts for further studies. In Chapter 4 we demonstrate using chemical and electrochemical techniques that one-electron reduction of Ni(-SNS)2 triggers quantitative imine C-C bond coupling, forming [Ni(S2N2)]- with a redox-active ligand. Spectroelectrochemical studies indicated reversible oxidation and reduction steps give three stable redox states, ([Ni(S2N2)]0/-/2-), that were characterized by NMR, EPR and UV-Vis spectroscopy, X-ray diffraction and computational chemistry. While the Ni(0) dianion (and not the Ni(I) anion) reacted reversibly with phenol and carbon dioxide, results from Chapter 5 showed that reactions with strong electron-acceptor fluoroalkenes proceeded more cleanly with the Ni(I) anion. The latter reactions afforded a mixture of fluoroalkenyl and fluoroalkyl products resulting from C-F bond activation and electron transfer/H atom abstraction, respectively. In Chapter 6 we discuss our results in the context of the current state of the art and suggest some avenues for future development.

Book Nickel Catalysis in Organic Synthesis

Download or read book Nickel Catalysis in Organic Synthesis written by Sensuke Ogoshi and published by John Wiley & Sons. This book was released on 2020-03-09 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive reference to nickel chemistry for every scientist working with organometallic catalysts Written by one of the world?s leading reseachers in the field, Nickel Catalysis in Organic Synthesis presents a comprehensive review of the high potential of modern nickel catalysis and its application in synthesis. Structured in a clear and assessible manner, the book offers a collection of various reaction types, such as cross-coupling reactions, reactions for the activation of unreactive bonds, carbon dioxide fixation, and many more. Nickel has been recognized as one of the most interesting transition metals for homogeneous catalysis. This book offers an overview to the recently developed new ligands, new reaction conditions, and new apparatus to control the reactivity of nickel catalysts, allowing scientists to apply nickel catalysts to a variety of bond-forming reactions. A must-read for anyone working with organometallic compounds and their application in organic synthesis, this important guide: -Reviews the numerous applications of nickel catalysis in synthesis -Explores the use of nickel as a relatively cheap and earth-abundant metal -Examines the versatility of nickel catalysis in reactions like cross-coupling reactions and CH activations -Offers a resource for academics and industry professionals Written for catalytic chemists, organic chemists, inorganic chemists, structural chemists, and chemists in industry, Nickel Catalysis in Organic Synthesis provides a much-needed overview of the most recent developments in modern nickel catalysis and its application in synthesis.

Book Synthesis and Characterization of Nickel Imine amine Complexes a Possible Model for Nickel Superoxide Dismutase

Download or read book Synthesis and Characterization of Nickel Imine amine Complexes a Possible Model for Nickel Superoxide Dismutase written by Tom Muinde Mwania and published by . This book was released on 2012 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superoxide dismutases are ubiquitous enzymes that efficiently catalyze the disproportionation of superoxide radical anions to protect biological molecules from oxidative damage. Several SODs have been identified having different metals at their active sites. These include Mn SOD, Fe SOD, Cu/Zn SOD and, most recently, Ni SOD. The catalytic center of Ni SOD resides in the N-terminal active-site loop, where a Ni(II) is coordinated by the amine N of His-1, the amide N of Cys-2, and two thiolate S atoms of Cys-2 and Cys-6. In the oxidized form, Ni(III) adds the imidazole N of His-1 as an axial ligand. For the past decade, we have been developing methodology using 2, 2'-dithiodibenzaldehyde (DTDB) for the synthesis of metal complexes with mixed N/S coordination. We are reporting on the application of this methodology to the synthesis of model complexes for the active site of NiSOD, in which we have successfully synthesized and characterized three NiIIN2S2 complexes of imine/amine N donors: Ni(NNS)SPh (1), Ni(NNS)SPhNO2 (2) and Ni(NNS)StBu (3). These may be used as a model for reduced NiSOD, with future plans of comparing to complexes with amide/amine N donors, thus establishing the role of the amide.

Book Synthesis and Characterization of Nickel II Complexes of a Hydrotrispyrazolylborato Ligand and of the Thiosalicylato Ligand

Download or read book Synthesis and Characterization of Nickel II Complexes of a Hydrotrispyrazolylborato Ligand and of the Thiosalicylato Ligand written by Weibin Chen and published by . This book was released on 1994 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis and Characterization of Nickel II Complexes with 1 4 7 10 tetrabenzyl 1 4 7 10 tetraazacyclododecane

Download or read book Synthesis and Characterization of Nickel II Complexes with 1 4 7 10 tetrabenzyl 1 4 7 10 tetraazacyclododecane written by George A. Kalligeros and published by . This book was released on 1971 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Organic Chemistry of Nickel Organic synthesis

Download or read book The Organic Chemistry of Nickel Organic synthesis written by P. W. Jolly and published by . This book was released on 1974 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vol. 2.