Download or read book High valent Nickel Complexes Supported by Pyridinedicarboxamidate Ligands in Hydrocarbon Oxidation Reactions written by Paolo Pirovano and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oxidative C C and C heteroatom Reactivity of High valent Nickel Complexes written by Sofia M. Smith and published by . This book was released on 2019 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nickel catalysts are commonly used for cross-coupling reactions such as Negishi, Kumada and Suzuki couplings. While Ni(0), Ni(I), and Ni(II) intermediates are most relevant in these transformations, Ni(III) and Ni(IV) species have also been recently proposed to play a role in catalysis. The formation of C-C and C-heteroatom bonds plays a fundamental role in organic transformations, and today cross-coupling reactions are one of the most powerful tools for the construction of new C-C bonds. However, limited examples exist of Ni-mediated C-heteroatom bond formation reactions, likely due to the difficulty of accessing high-valent organometallic Ni species that can undergo reductive elimination.One way to expand our knowledge of these C-C and C-heteroatom atom bond formation reactions is to look at the stabilization and destabilization effects of the high-valent nickel complexes. Studying these effects will help us determine the most efficient way in performing C-C and C-heteroatom atom bond formation reactions. Tetradentate pyridinophane ligands have been to stabilize uncommon high-valent organometallic nickel complexes. By varying the N-substituents, we are now able to probe the stabilization and destabilization effects that might play a crucial role in the C-C and C-heteroatom atom bond formation reactions.A series of nickel complexes were synthesized to probe the C-C and C-heteroatom atom bond reactivity using the Ni-dimethyl and -metallacycle complexes. These complexes were fully characterized and their reactivity was tested. The oxidative reactivity was studied by looking at a variety of oxidants which include dioxygen and hydrogen peroxide to probe any C-O bond formation. Interestingly, while the oxidation of the NiII metallacycle complexes with various oxidants led to exclusive C-C bond formation in very good yields, the use of O2 or H2O2 as oxidants led to appreciable amounts of C-O bond formation products, especially for an asymmetric pyridinophane ligand with one tosyl N-substituent. Moreover, cryo-ESI-MS studies strongly support the formation of several high-valent nickel species as key intermediates in this unprecedented aerobic Ni-mediated oxygenase-type chemistry.Lastly, the tetradentate pyridinophane ligands were used in two catalytic oxidation reactions, a hydroxylation and a chlorination reaction for unactivated alkanes. These catalytic oxidation reactions use mild oxidants such as hypohalites which are commercially available. All these reactions could have important implications in organic transformations.
Download or read book Oxidative C C Bond Formation Reactivity of High Valent Nickel and Palladium Complexes written by Michael Benjamin Watson and published by . This book was released on 2017 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of both palladium and nickel catalysis over the past several decades has led to the ability to perform a multitude of C-C coupling, C-Heteroatom coupling, and C-H functionalization reactions. These reactions typically utilize a catalytic cycle involving Pd0/II/IV and Ni0/II. While using these types of catalytic cycles one can create a multitude of different hard to make bonds, it is always important to keep expanding what we view as potential catalytic intermediates to keep developing new cycles capable of new transformations. One such way to expand our knowledge of these catalytic cycles is to look at the oxidation states that are less commonly observed in catalysis. This typically involves PdI/III and NiI/III/IV. Studying these rare oxidation states allows us to determine if they have the potential to either take part in current catalytic cycles, or develop new ones that take advantage of these oxidation states. Our group has previously synthesized various PdIII and NiIII complexes with the support of N,N'- dialkyl-2,11-diaza[3.3](2,6)pyridinophane (RN4). This ligand has allowed for the isolation and characterization of these complexes that are typically seen as unstable letting us study their reactivity. First, we investigated the effects of ligand flexibility on the stabilization of PdIII complexes by synthesizing several ligands. The "flexible" ligands had a 1,4,7-triazacyclononane framework and the "rigid" ligands had a diazabicylononanone framework. Seeing that the flexible 1,4,7- triazacyclononane ligands seemed to be better at stabilizing the high valent palladium, we continued using it to synthesize organometallic nickel complexes. These complexes proved very easy to oxidize allowing NiII/III/IV oxidation states to be isolated and fully characterized. The oxidative reactivity was studied for these three nickel complexes looking at oxidative addition with organic halides, aerobic oxidation, and most interestingly photolysis that resulted in much faster reductive elimination from the NiIV species. Lastly, we investigated the ligand modifications that can be done to either stabilize or destabilize high valent NiIII species using a N,N'-dialkyl-2,11- diaza[3.3](2,6)pyridinophane ligand that was modified to observe the effect on differing amounts of steric bulk and electronic effects. Studying these rare high valent complexes is important so we can continue to expand the scope of what catalytic transformations we can use to improve our daily lives.
Download or read book Oxygen Atom Transfer Reactions written by Robert Bakhtchadjian and published by Bentham Science Publishers. This book was released on 2023-01-11 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces readers to the fundamentals of oxygen atom transfer reactions. It also gives mechanistic insights into the redox processes occurring through the oxygen atom transfer reactions. It also includes information about catalytic activation of oxygen through enzymes and oxo-metallic complexes. All topics are explored in separate chapters. Key features: - reviews the basic mechanisms in redox processes involving oxo-atom transfer reactions. - presents progress in the biomimetic activation of dioxygen related to the catalytic oxidations by synthetic metal organic complexes. - covers an important class of metal-organic compounds - nickel-oxygen species - generated in catalytic oxidation processes as oxygen atom transfer agents. - explains the mechanistic aspects of the heterogeneous photochemical redox processes via oxo-atom transfer reactions - provides references for further reading It is a reference for both professional scientists in the fields of chemistry, biology and applied sciences, and for graduate and undergraduate students interested in understanding reaction mechanisms involving oxygen.
Download or read book Development of Nickel II Complexes of Oxime Containing Ligands for the Activation of Dioxygen written by Michael Joseph Goldcamp and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ligands containing two oxime donor groups with a variable third group in a tripodal amine motif have been designed and synthesized. Their Ni(II) complexes, and some Zn(II), Cu(II), and Fe(III) complexes, have been structurally and spectroscopically characterized. Deprotonation of the oxime groups gives Ni(II)--Polyoximate complexes that form bis(N-O) oximate bridged dimers with significantly low oxidation potentials for Ni(II). These Ni(II)-polyoximate complexes react with dioxygen, consuming multiple equivalents. This is unusual chemistry for Ni(II), especially in the absence of ligand oxidation. The Ni(II) / O 2 reaction system promotes oxidation of triphenyl phosphine, with oxygen atom transfer, benzyl alcohol, and 3,5-di-tert-butylcatechol. Reaction of the Ni(II)-polyoximate complexes with o-quinones causes the formation of high-valent nickel complexes of the reduced dioxolenes, semiquinones and catecholates.
Download or read book Reaction Mechanisms in Carbon Dioxide Conversion written by Michele Aresta and published by Springer. This book was released on 2015-11-07 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an analysis of the reaction mechanisms relevant to a number of processes in which CO2 is converted into valuable products. Several different processes are considered that convert CO2 either in specialty chemicals or in bulk products or fuels. For each reaction, the mechanism is discussed and the assessed steps besides the dark sites of the reaction pathway are highlighted. From the insertion of CO2 into E-X bonds to the reduction of CO2 to CO or other C1 molecules or else to C2 or Cn molecules, the reactions are analysed in order to highlight the known and obscure reaction steps. Besides well known reaction mechanisms and energy profiles, several lesser known situations are discussed. Advancing knowledge of the latter would help to develop efficient routes for the conversion of CO2 into valuable products useful either in the chemical or in the energy industry. The content of this book is quite different from other books reporting the use of CO2. On account of its clear presentation, “Reaction Mechanisms in Carbon Dioxide Conversion” targets in particular researchers, teachers and PhD students.
Download or read book C X Bond Formation written by Arkadi Vigalok and published by Springer. This book was released on 2010-06-30 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: Kilian Muñiz: Transition Metal Catalyzed Electrophilic Halogenation of C-H bonds in alpha-Position to Carbonyl Groups; Arkadi Vigalok * and Ariela W Kaspi: Late Transition Metal-Mediated Formation of Carbon-Halogen Bonds; Paul Bichler and Jennifer A. Love*: Organometallic Approaches to Carbon-Sulfur Bond Formation; David S. Glueck: Recent Advances in Metal-Catalyzed C-P Bond Formation; Andrei N. Vedernikov: C-O Reductive Elimination from High Valent Pt and Pd Centers; Lukas Hintermann: Recent Developments in Metal-Catalyzed Additions of Oxygen Nucleophiles to Alkenes and Alkynes; Moris S. Eisen: Catalytic C-N, C-O and C-S bond formation promoted by organoactinide complexes.
Download or read book The Oxidation of Cyclohexane written by I. V. Berezin and published by Elsevier. This book was released on 2018-04-12 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Oxidation of Cyclohexane focuses on the processes, methodologies, reactions, and approaches involved in the oxidation of cyclohexane. The publication first offers information on the theory of slow chain oxidations and the products of liquid-phase cyclohexane oxidation. Discussions focus on the applicability of the stationary state method to liquid-phase oxidation reactions; mechanism of liquid hydrocarbon chain oxidation; kinetic equations for product accumulation in degenerate branching chain reactions; and changes of the volume of the liquid phase due to oxidation product formation. The text then ponders on experimental apparatus for the study of the liquid-phase oxidation of cyclohexane, including prevention of cyclohexane losses in the waste gases, explosion danger and problems of safety, and characteristics of gas sampling in cyclohexane oxidation apparatus. The manuscript takes a look at the kinetics of uncatalyzed cyclohexane oxidation and kinetics of cyclohexane oxidation in continuous flow systems. Topics include effect of temperature on the relative yield of cyclohexane oxidation products; kinetics of cyclohexane oxidation in a glass reactor; rate of oxygen absorption and accumulation of reaction products; ideal displacement reactor; and determination of diffusion factor. The publication is a dependable reference for readers interested in the oxidation of cyclohexane.
Download or read book Handbook of Bond Dissociation Energies in Organic Compounds written by Yu-Ran Luo and published by CRC Press. This book was released on 2002-12-26 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: So many compounds, so many experiments reported by so many researchers using so many methods Finding reliable data on bond dissociation energies (BDEs) can be like looking for a needle in a haystack. But these data are crucial to work in chemical kinetics, free radical chemistry, organic thermochemistry, and physical organic chemistry-so where does
Download or read book The Bioinorganic Chemistry of Nickel written by Jack R. Lancaster and published by Wiley-VCH. This book was released on 1988 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Science of Synthesis Dual Catalysis in Organic Synthesis 1 written by G. A. Molander and published by Thieme. This book was released on 2020-05-22 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of dual catalysis has developed rapidly over the last decade, and these volumes define its impact on organic synthesis. The most important, basic concepts of synergistic, dual catalytic cycles are introduced, providing newcomers to the field with reliable information on this new approach to facilitating the synthesis of organic molecules. Background information and reliable procedures for challenging transformations in synthesis are presented, applying the concept of cooperative dual catalysis as a means of increasing molecular complexity in the most efficient manner. The most useful, practical, and reliable methods for dual catalysis combining metal catalysts, organocatalysts, photocatalysts, and biocatalysts are presented.
Download or read book Metal Complexes with Tetrapyrrole Ligands I written by Johann W. Buchler and published by Springer. This book was released on 1987-07-08 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elements of Molecular and Biomolecular Electrochemistry written by Jean-Michel Savéant and published by John Wiley & Sons. This book was released on 2006-02-10 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is based on the George Fisher Baker Lecture given by Jean-Michel Savéant at Cornell University in Fall 2002. * The first book focusing on molecular electrochemistry * Relates to other fields, including photochemistry and biochemistry * Outlines clearly the connection between concepts, experimental illustrations, proofs and supporting methods * Appendixes to provide rigorous demonstrations to prevent an overload of algebra in the main text * Applications-oriented, focused on analyzing the results obtained rather than the methodology
Download or read book COSMO RS written by Andreas Klamt and published by Elsevier. This book was released on 2005-07-26 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: The COSMO-RS technique is a novel method for predicting the thermodynamic properties of pure and mixed fluids which are important in many areas, ranging from chemical engineering to drug design. COSMO-RS, From Quantum Chemistry to Fluid Phase Thermodynamics and Drug Design is about this novel technology, which has recently proven to be the most reliable and efficient tool for the prediction of vapour-liquid equilibria. In contrast to group contribution methods, which depend on an extremely large number of experimental data, COSMO-RS calculates the thermodynamic data from molecular surface polarity distributions, resulting from quantum chemical calculations of the individual compounds in the mixture. In this book, the author cleverly combines a vivid overview of the partly demanding theoretical steps with a deeper analysis of their scientific background and justification. Aimed at theoretical chemists, computational chemists, physical chemists, chemical engineers, thermodynamicists as well as students,academic and industrial experts, COSMO-RS, From Quantum Chemistry to Fluid Phase Thermodynamics and Drug Design provides a novel viewpoint to anyone looking to gain more insight into the theory and potential of the unique method, COSMO-RS. The only book currently available on COSMO-RS technique Provides a novel viewpoint for the scientific understanding and for the practical quantitative treatment of fluid phase thermodynamics Includes illustrative examples of the COSMOtherm program
Download or read book Biomolecular EPR Spectroscopy written by Wilfred Raymond Hagen and published by CRC Press. This book was released on 2008-12-22 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive, Up-to-Date Coverage of Spectroscopy Theory and its Applications to Biological SystemsAlthough a multitude of books have been published about spectroscopy, most of them only occasionally refer to biological systems and the specific problems of biomolecular EPR (bioEPR). Biomolecular EPR Spectroscopy provides a practical introduction t
Download or read book Through My Eyes written by Alton Gansky and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: These are not mere dreams and visions: these are a calling.Six people. Five mind-numbing visions. Four ancient and mysterious artifacts. Two exotic locations. And one greedy man who will stop at nothing, not even murder, to achieve his goal.Rev. Adam Bridger and his wife, Dr. Rachel Tremaine are once again in the center of an adventure not of their making. And joing them are four total strangers who, along with Rachel, have seen visions that most mortals can't imagine. They have been called on a mission that will forever change the world--if they survive.
Download or read book Comprehensive Handbook of Chemical Bond Energies written by Yu-Ran Luo and published by CRC Press. This book was released on 2007-03-09 with total page 1685 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the energy it takes to build or break chemical bonds is essential for scientists and engineers in a wide range of innovative fields, including catalysis, nanomaterials, bioengineering, environmental chemistry, and space science. Reflecting the frequent additions and updates of bond dissociation energy (BDE) data throughout the literat
