Download or read book Palladium Complexes of Benzoimidazol 2 ylmethyl Amine Ligands written by Thandeka Adelinah Tshabalala and published by . This book was released on 2014 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Reactivity of Palladium Complexes that Contain Redox active Verdazyl Ligands written by Corey A. Sanz and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the synthesis, characterization and reactivity of a series of palladium complexes that contain redox-active verdazyl ligands. This work was motivated by the possibility of discovering new and interesting reactivity that may eventually lead to the development of new chemical reactions. A bidentate verdazyl radical ligand that contains an aryl phosphine was synthesized. Reaction of this ligand with (PhCN)2PdCl2 yielded a square planar (verdazyl)PdCl2 complex. Structural and spectroscopic data suggest that this compound consists of a ligand-centered radical coordinated to a Pd(II) center. The radical complex was chemically reduced by one-electron to generate a binuclear chloride-bridged [(verdazyl)PdCl]2 complex. In this reduced complex, both metals were still Pd(II) and the verdazyl ligand was determined to be in its singly reduced, monoanionic charge state. The original radical PdCl2 complex could be regenerated via one-electron oxidation of the reduced complex using PhICl2. The verdazyl ligands in the reduced complex could also be reversibly protonated to generate "leuco" verdazyl complex (verdazyl-H)PdCl2. Reaction of the radical (verdazyl)PdCl2 complex with water triggers a ligand-centered redox disproportionation reaction. A series of bis(verdazyl) palladium complexes were synthesized using a bidentate pyridine-substituted verdazyl ligand. Reaction of two equivalents of radical ligand with (CH3CN)4Pd2+ yielded a (verdazyl)2Pd(solvent)2+ complex (solvent = CH3CN or DMSO). In this complex, one verdazyl radical ligand chelates to palladium and the other binds as a monodentate ligand. Two-electron reduction of this complex generated a (verdazyl)2Pd complex in which two monoanionic verdazyl ligands are bound to a central Pd(II) ion. This reduced complex could also be made via reaction of 0.5 equivalents of Pd(0)2(dba)3 with two equivalents of radical ligand. In this reaction, the metal is oxidized by two electrons and each ligand is reduced by a single electron. Two-electron oxidation of the reduced complex in the presence of DMSO yielded the original bis(radical)complex, (verdazyl)2Pd(DMSO)2+. Chlorination of the reduced complex using one equivalent of PhICl2 (two-electron oxidation) resulted in dissociation of one verdazyl ligand to afford a 1:1 mixture of free verdazyl : (verdazyl)PdCl2, in which both of the verdazyls are neutral radicals. Reaction of the reduced complex with 0.5 equivalents of PhICl2 (one-electron oxidation) yielded a (verdazyl)2PdCl complex that contained a bidentate reduced verdazyl ligand and a monodentate radical ligand. All three of the oxidation reactions described above adhere to ligand-centered redox chemistry. Reaction of the reduced (verdazyl)2Pd complex with excess HCl resulted in protonation of both the anionic verdazyl ring and the pyridyl group to generate a leuco/pyridinium tetrachloropalladate salt, (verdazyl-H2)2(PdCl4). The protonated salt could be converted back to the original (verdazyl)2Pd complex by deprotonation with water. Palladium complexes of a tridentate NNN-chelating verdazyl ligand were prepared and their redox chemistry was explored. Reaction of the radical ligand with (CH3CN)4Pd2+ yielded radical complex (verdazyl)Pd(NCCH3)2+. The tridentate ligand was also prepared in its reduced, leuco form (verdazyl-H). Reaction of the leuco verdazyl with (CH3CN)2PdCl2 generated HCl and a (verdazyl)PdCl complex in which the ligand is in its monoanionic charge state. The reduced (verdazyl)PdCl complex was reacted with AgBF4 to afford (verdazyl)Pd(NCCH3)+ via chloride abstraction; the verdazyl remained in its reduced charge state following the reaction. Both reduced complexes (chloro and acetonitrile) were oxidized by a single electron to afford the corresponding radical complexes. These radical complexes could be reduced by a single electron to regenerate the original reduced complexes. Like the previous two projects, all of the redox chemistry was ligand-centered. The reactivity of these complexes with primary amines was also explored. Reaction of radical complex (verdazyl)Pd(NCCH3)2+ with n-butylamine resulted in one-electron reduction of the verdazyl ligand. We were unable to determine the mechanism of the reaction, but the reactivity that was observed demonstrates the potential for verdazyl-palladium complexes to be used in the design of new radical reactions.
Download or read book Synthesis Characterization and Reactivity of Mononuclear Palladium Complexes Bearing Nitrogen and Carbon donor Ligands written by Nicholas Ruhs and published by . This book was released on 2017 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: The importance of Pd-catalyzed C--H functionalization reactions for chemical transformations has been widely studied over the last several decades. Much of the research to date has focused on conventional Pd0/II catalytic cycles. However, more recent studies have shown that many transformations can also follow a PdII/IV catalytic cycle. High-valent PdIII and PdIV species are often proposed to be important intermediates in such transformations. C--H coupling reactions involving high-valent intermediates often involve the oxidation of a PdII species to a PdIII or PdIV complex, which can then undergo subsequent C--heteroatom bond formation. However, the need for harsh oxidants and reaction conditions in many of these reactions hinders their practical applicability. The focus of this work is to study the properties and reactivity of PdII, PdIII, and PdIV complexes through modifications of the supporting macrocyclic ligands. Another goal of this work is to probe the ability of these complexes to facilitate C--H activation and C--heteroatom bond formation reactions using environmentally benign oxidants.Our lab reported the synthesis and characterization of the first organometallic mononuclear PdIII complexes stabilized by the tetradentate ligand N,N'-di-tert-butyl-2,11-diaza[3,3](2,6)pyridinophane (tBuN4). In order to further probe the Pd chemistry with this class of ligands, we prepared ligands with modifications to the steric bulk on the amine groups. In the first study detailed in chapter 2, the synthesis and characterization of PdII and PdIII complexes supported by N,N'-di-neo-pentyl-2,11-diaza[3,3](2,6)-pyridinophane(NpN4) and N,N'-di-benzyl-2,11-diaza[3,3](2,6)-pyridinophane(BzN4) is reported. Interestingly, the spectroscopic and crystallographic property of the newly synthesized complexes falls between the tBuN4 and MeN4 complexes. The C--C and C--heteroatom bond formation reactivity of the NpN4 and BzN4 supported complexes is also similar to our group's previously reported complexes.We also prepared and studied a series of Pd complexes bearing a modified tetradentate pyridinophane ligand, tBuN3CH. Essentially, we have replaced one of the nitrogen donor atoms from the N4 ligand with a carbon atom and have also introduced a new C--H bond. Due to its expected positioning near the metal center, this bond has the potential to undergo intramolecular C--H bond activation. In order to study the reactivity of this ligand, electronic modifications were made by substituting various electron-donating and withdrawing groups in the para position to this new C--H bond. In chapter 3, the synthesis and characterization of a series of PdII, PdIII, and PdIV complexes stabilized by the N3CH ligand is reported. Interestingly, a spectroscopic and crystallographic study of the pRN3CHPdII(OAc)2 complexes reveals that the Cipso--H bond remains unactivated at the PdII stage. However, upon oxidation to PdIII, the Cipso--H bond is activated.Interestingly, we discovered that the aerobic oxidation of the PdII complex [pRN3CHPdII(MeCN)](BF4) leads to the formation of the PdIII complex [pRN3CHPdIII(MeCN)](ClO4)2 at room temperature. Surprisingly, the C--H activation reaction proceeds in the presence of oxygen without the need for external base. Furthermore, the moderate rate of the reaction allowed us to investigate the mechanism of the reaction by utilizing kinetics and UV-Vis spectroscopy. Detailed mechanistic studies revealed that C--H activation of the Cipso--H bond is the rate determining step of the reaction.
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 Advances in Heterocyclic Chemistry written by Alan R. Katritzky and published by Academic Press. This book was released on 2010-07-03 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Established in 1960, Advances in Heterocyclic Chemistry is the definitive serial in the area—one of great importance to organic chemists, polymer chemists, and many biological scientists. Written by established authorities in the field, the comprehensive reviews combine descriptive chemistry and mechanistic insight and yield an understanding of how the chemistry drives the properties. Provides up-to-date material on a fast growing and highly topical subject area Contains the latest research covering a wide variety of heterocyclic topics Written by leading authorities and designed as a handbook for students and industry and academic researchers
Download or read book Heavy Metals Advances in Research and Application 2012 Edition written by and published by ScholarlyEditions. This book was released on 2012-12-26 with total page 1713 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heavy Metals—Advances in Research and Application: 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Heavy Metals. The editors have built Heavy Metals—Advances in Research and Application: 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Heavy Metals 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 Heavy Metals—Advances in Research and Application: 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/.
Download or read book Chemistry and Applications of Benzimidazole and its Derivatives written by Maria Marinescu and published by BoD – Books on Demand. This book was released on 2019-10-02 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Finding new strategies for synthesizing benzimidazole derivatives and functionalizing the benzimidazole core has proved to be important due to the compound's various applications in medicine, chemistry, and other areas. The multitude of benzimidazole derivatives marketed as drugs has led to intensive research in the field for the discovery of new biologically active structures. The general applications of benzimidazole derivatives in materials chemistry, electronics, technology, dyes, pigments, and agriculture open up new research horizons. This book guides the rational design of benzimidazole derivatives synthesis with certain applications. Chapters cover such topics as therapeutic use of benzimidazole in conditions like diabetes, viruses, and parasitic diseases; X-ray crystal structure of selected benzimidazole derivatives; benzimidazole compounds for cancer therapy; and others.
Download or read book Cross coupling Reactions written by Joffrey Vrijdag and published by . This book was released on 2020 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Cross-Coupling Reactions: An Overview opens with an overview of the fundamentals and applications of the young and fast developing area of transition metal catalyzed/mediated oxidative (dehydrogenative) C-H/C-H coupling reactions between two (hetero)arenes. Continuing, the authors highlight the recent advances regarding the ligand supported transition metal-catalyzed domino (cascade) or one-pot syntheses of various heterocycles involving cross-coupling reactions. The recent advances in Cu catalyzed tandem reactions for heterocycle synthesis are also addressed. Cu metal chemistry has garnered attention as a potential alternative to precious transition metals, being cheaper, more sustainable and more easily available. A comprehensive account of research on green chemical routes is provided, involving various palladium metal-based catalysts utilized in facilitating cross-coupling reaction in aqueous media. Reported decarboxylative cross-coupling reactions are discussed along with suitable examples, focusing on their mechanism of action"--
Download or read book Springer Handbook of Inorganic Photochemistry written by Detlef Bahnemann and published by Springer Nature. This book was released on 2022-06-25 with total page 1914 pages. Available in PDF, EPUB and Kindle. Book excerpt: The handbook comprehensively covers the field of inorganic photochemistry from the fundamentals to the main applications. The first section of the book describes the historical development of inorganic photochemistry, along with the fundamentals related to this multidisciplinary scientific field. The main experimental techniques employed in state-of-art studies are described in detail in the second section followed by a third section including theoretical investigations in the field. In the next three sections, the photophysical and photochemical properties of coordination compounds, supramolecular systems and inorganic semiconductors are summarized by experts on these materials. Finally, the application of photoactive inorganic compounds in key sectors of our society is highlighted. The sections cover applications in bioimaging and sensing, drug delivery and cancer therapy, solar energy conversion to electricity and fuels, organic synthesis, environmental remediation and optoelectronics among others. The chapters provide a concise overview of the main achievements in the recent years and highlight the challenges for future research. This handbook offers a unique compilation for practitioners of inorganic photochemistry in both industry and academia.
Download or read book Advances in Structure and Activity Relationship of Coumarin Derivatives written by Santhosh Penta and published by Academic Press. This book was released on 2015-08-07 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Structure and Activity Relationship of Coumarin Derivatives covers the structural behavior of various coumarin derivatives for various potential pharmaceutical applications. Based on substitution targeted for active sites, the book takes a rational approach for designing new and specific potent drugs, optimizing existing ones, and developing novel reactions. This focused primer describes the chemical structure and activity of coumarin derivatives to explore the effects of different substituents at specific positions, and their properties for effective bioactivity. Accessible and current coverage of coumarin derivatives from structure to potential applications Application of SAR technology to predict bioactivity of the derivatives based on its chemical structure Information for researchers in medicinal chemistry, pharmaceutical sciences, and related fields
Download or read book Applications of Density Functional Theory to Biological and Bioinorganic Chemistry written by Mihai V. Putz and published by Springer. This book was released on 2013-02-01 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Structure and Bonding publishes critical reviews on topics of research concerned with chemical structure and bonding. The scope of the series spans the entire Periodic Table and addresses structure and bonding issues associated with all of the elements. It also focuses attention on new and developing areas of modern structural and theoretical chemistry such as nanostructures, molecular electronics, designed molecular solids, surfaces, metal clusters and supramolecular structures. Physical and spectroscopic techniques used to determine, examine and model structures fall within the purview of Structure and Bonding to the extent that the focus is on the scientific results obtained and not on specialist information concerning the techniques themselves. Issues associated with the development of bonding models and generalizations that illuminate the reactivity pathways and rates of chemical processes are also relevant. The individual volumes in the series are thematic. The goal of each volume is to give the reader, whether at a university or in industry, a comprehensive overview of an area where new insights are emerging that are of interest to a larger scientific audience. Thus each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years should be presented using selected examples to illustrate the principles discussed. A description of the physical basis of the experimental techniques that have been used to provide the primary data may also be appropriate, if it has not been covered in detail elsewhere. The coverage need not be exhaustive in data, but should rather be conceptual, concentrating on the new principles being developed that will allow the reader, who is not a specialist in the area covered, to understand the data presented. Discussion of possible future research directions in the area is welcomed. Review articles for the individual volumes are invited by the volume editors. Readership: research scientists at universities or in industry, graduate students Special offer For all customers who have a standing order to the print version of Structure and Bonding, we offer free access to the electronic volumes of the Series published in the current year via SpringerLink.
Download or read book Cadmium From Toxicity to Essentiality written by Astrid Sigel and published by Springer Science & Business Media. This book was released on 2013-02-26 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 11 provides in an authoritative and timely manner in 16 stimulating chapters, written by 40 internationally recognized experts from 11 nations, and supported by more than 2600 references, 35 tables, and over 100 illustrations, many in color, a most up-to-date view on the role of cadmium for life, presently a vibrant research area. MILS-11 covers the bioinorganic chemistry of Cd(II), its biogeochemistry, anthropogenic release into the environment, and speciation in the atmosphere, waters, soils, and sediments. The analytical tools for Cd determination, its imaging in cells, and the use of 113Cd NMR to probe Zn(II) and Ca(II) proteins are summarized, as are Cd(II) interactions with nucleotides, nucleic acids, amino acids, and proteins including metallothioneins. The phytoremediation by Cd(II)-accumulating plants, etc., the toxicology of Cd(II), its damage to mammalian organs, and its role as a carcinogen for humans, are highlighted.
Download or read book Inorganic Syntheses Volume 33 written by and published by John Wiley & Sons. This book was released on 2004-08-04 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Inorganic Syntheses series provides inorganic chemists with detailed and foolproof procedures for the preparation of important and timely compounds. Volume 33 includes provocative contributions on syntheses of selected supramolecules, useful reagents/ligands, solid state materials/clusters, and other compounds of general interest.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2720 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Click Triazoles written by Janez Košmrlj and published by Springer. This book was released on 2012-05-30 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: B. R. Buckley and H. Heaney: Mechanistic Investigations of Copper(I)- Catalyzed Alkyne–Azide Cycloaddition Reactions.- J. D. Crowley and D. A. McMorran: “Click-Triazole” Coordination Chemistry: Exploiting 1,4-Disubstituted-1,2,3-Triazoles as Ligands.- S. Lee and A. H. Flood: Binding Anions in Rigid and Reconfigurable Triazole Receptors.- M. Watkinson: Click Triazoles as Chemosensors.- H.-F. Chow, C.-M. Lo and Y. Chen: Triazole-Based Polymer Gels.- T. Zheng, S. H. Rouhanifard, A. S. Jalloh, P. Wu: Click Triazoles for Bioconjugation.- S. Mignani, Y. Zhou, T. Lecourt and L. Micouin: Recent Developments in the Synthesis 1,4,5-Trisubstituted Triazoles.
Download or read book Quinoxalines written by Vakhid A. Mamedov and published by Springer. This book was released on 2016-04-26 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book reviews the fundamental aspects of quinoxaline chemistry: synthesis, reactions, mechanisms, structure, properties, and uses. The first four chapters present a survey of the developments in quinoxaline chemistry since the publication of the monograph on “Condensed Pyrazines” by Cheeseman and Cookson in 1979. These chapters give comprehensive coverage of all the methods of the synthesis of quinoxalines and the important quinoxaline-containing ring systems such as thiazolo[3,4-a]-, pyrrolo[1,2-a]-, and imidazo[1,5-a]quinoxalines. Chapter five describes many new methods for the construction of quinoxaline macrocycles, which are important in applications such as optical devices and materials. The final chapter reviews all previously known rearrangements of heterocyclic systems that lead to benzimidazole derivatives. Mamedov critically analyses these transformations to reveal a novel acid-catalyzed rearrangement of quinoxalinones giving 2-heteroarylbenzimidazoles and 1-heteroarylbenzimidazolones in the presence of nucleophilic reactants (MAMEDOV Heterocycle Rearrangement). This book is of interest to researchers in the fields of heterocyclic and synthetic organic chemistry.
Download or read book Chemistry of Polymeric Metal Chelates written by Gulzhian I. Dzhardimalieva and published by Springer. This book was released on 2018-02-13 with total page 1036 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with the chemistry of polymeric metal chelates. The main results and the production and chemical structure of polymers with chelate units as well as the specificity of metal complex binding of different structure are presented here. This book also reveals the transformations which components undergo in the course of chelation. Special attention is paid not only to synthetic but also to natural (including living) systems. The usage of polymeric metal chelates and their development are examined. The related research was performed for chelates with chain structure. This book is useful to researchers being active in synthesis and design of macromolecular metal chelates
