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Book Synthesis of New Nickel Complexes with N S ligand Systems

Download or read book Synthesis of New Nickel Complexes with N S ligand Systems written by Christopher B. Lavery and published by . This book was released on 2009 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis of Phosphino silyl Ligated Nickel Complexes for the Catalytic Hydroboration of Alkenes

Download or read book Synthesis of Phosphino silyl Ligated Nickel Complexes for the Catalytic Hydroboration of Alkenes written by Sydney Shepard and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bis(phosphino)silyl (PSiP) pincer ligands have been studied extensively. While there are several examples of late transition metal complexes, in recent years there has been a shift to study these ligands on first-row transition metals (i.e., Fe, Co, Ni). These complexes have shown to be active in catalytic hydrofunctionalization; however, the turn-over for larger substrates has proved challenging. Therefore, the question of reducing the size of the phosphino(silyl) ancillary ligand is investigated in this document. While varying the substitution at phosphorus is common, access to smaller substituents is not straightforward. A different approach is to eliminate a phosphine donor. A new bidentate PSi ligand has been synthesized and studied with respect to Ni complexes. In this regard, studying the catalytic hydroboration with a substrate scope involving terminal, di-, and tri-substituted alkenes and three Ni(II) precatalysts has been explored, where selectivity for chain-walking of internal alkenes to the terminal position was observed.

Book Synthesis and Initial Reactivity Studies of Nickel Complexes on a Pincer Scaffold

Download or read book Synthesis and Initial Reactivity Studies of Nickel Complexes on a Pincer Scaffold written by Huy Dao and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalytic oxidation reactions are prevalent in the chemical industry. The catalysts are often made with expensive metals and the mechanism(s) by which they operate are not well known. Studies of small molecules can lead to better understanding of mechanisms and thus lead to better catalysis design. Work has also been performed in designing catalysts using less costly metals. Nickel is one such metal, as it is a congener of platinum and palladium, two costly metals used widely in catalysis. Ligands can be altered to influence electronic and steric properties of the metal complexes, thus affecting catalytic activity. This thesis addresses the modification of an SCS pincer ligand and the synthesis of new nickel-SCS pincer complexes. Pincers are tridentate ligands that bind at adjacent coplanar sites. The designation "SCS" refers to the atoms at the coordination sites. The nickel-pincer complexes in this work are built from 2,6- bis(alkylthiomethyl)bromobenzene skeletons, with the alkyl groups being altered. The work presented herein describes the synthesis and characterization of Ni(SCSiPr)Br, Ni(SCStBu)Br, Ni(SCSMe)OPh, and Ni(SCSMe)Me. The reactivity of Ni(SCSMe)Me was studied and found to form Ni(SCSMe)OPh when reacted with phenol. This showed that Ni(SCSMe)Me was able to deprotonate an acidic species to form a new complex. Ni(SCSMe)Me was also found to catalyze the oxidation of triphenylphosphine to triphenylphosphine oxide when dry O2 was introduced. Eight to ten turnovers were observed.

Book The Organic Chemistry of Nickel

Download or read book The Organic Chemistry of Nickel written by P.W. Jolly and published by Elsevier. This book was released on 2012-12-02 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Organic Chemistry of Nickel, Volume II: Organic Synthesis describes the chemistry of the organonickel complexes and the use of nickel in organic synthesis. Composed of six chapters, this volume starts with discussions on the oligomerization, co-oligomerization, and polymerization of olefins, followed by short accounts of the mechanistically related isomerization and hydrogenation of olefins, as well as the hydrosilylation and hydrocyanation reactions. Chapter II examines the oligomerization of acetylene and substituted alkynes, the co-oligomerization of alkynes with olefins, the related oligomerization of allene, including a number of telomerization reactions involving alkynes or allenes. Chapters III and IV describe the oligomerization, co-oligomerization, and polymerization of butadiene and substituted 1,3-dienes. Chapter V explores the coupling of organic halides in the presence of stoichiometric amounts of zerovalent nickel complexes, and the nickel-catalyzed cross-coupling reaction between organic halides and Grignard reagents. Lastly, Chapter VI emphasizes the carbonylation of alkynes, olefins, and organic halides using nickel complexes. This book will be of great value to organic chemists and researchers who are interested in the application of nickel complexes to organic synthesis.

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 of a Hydrotrispyrazolylborate Ligand and of Novel Phosphinetrithiol Ligands

Download or read book Synthesis and Characterization of Nickel II Complexes of a Hydrotrispyrazolylborate Ligand and of Novel Phosphinetrithiol Ligands written by Weihong Zhang and published by . This book was released on 1990 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Synthesis of New Iron and Nickel Complexes

Download or read book Synthesis of New Iron and Nickel Complexes written by Anthony Kermagoret and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: My Ph-D thesis concerns the study of the catalytic oligomerization reaction with nickel, iron and cobalt complexes coordinated by N-O, P-N, N-P-N, P-O and P-N-P type ligands with a N donor atom represented by an oxazoline or a pyridine heterocycle. These complexes activated by a cocatalyst such as MAO or AlEtCl2 showed high activities and a high selectivity of C4 olefins in ethylene oligomerization. The nickel complexes with P-N chelates showed a high impact of the P substituents on the oligomerization selectivities. Moreover, the crystallographic studies on nickel complexes coordinated by N-O and P-N type ligands showed the formation of mono-, di- and tetranuclear complexes. The cobalt, iron and palladium complexes with N-P-N ligands highlighted original N-N, P-N or N-P-N coordination modes of the ligands influenced by the ligand substituents and the metal center.

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.

Book Synthesis and Characterization of Nickel II Compounds with Sulfur Donor Ligands

Download or read book Synthesis and Characterization of Nickel II Compounds with Sulfur Donor Ligands written by Li Zhou and published by . This book was released on 1995 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Studies in Bioinorganic Chemistry

Download or read book Studies in Bioinorganic Chemistry written by Roxanne Michelle Jenkins and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As inspired by the coordination environment of nickel in NikR and NiSOD, imidazole ligands were incorporated into N2SNiII square planar complexes in order to investigate the electronic and structural features of NiII species containing both imidazole and thiolate ligation. Rare examples of nickel complexes containing such ligand sets in continuous tetradentate (N2N'S) and discontinuous (N2S---N') coordination were synthesized and characterized. A significant finding in these studies is that the plane of the imidazole ligand is oriented perpendicular to the N2SNi plane. Further investigations addressed the orientational preference and stereodynamic nature of flat monodentate ligands (L = imidazoles, pyridine and an N-heterocyclic carbene) bound to planar N2SNi moieties. The solid state molecular structures of planar [N2SNiL]n+ complexes accessed through bridge-splitting reactions of dimeric, thiolate-S bridged [N2SNi]2 complexes, reveal that the plane of the added monodentate ligand orients largely orthogonal to the N2SNiL square plane. Variable temperature 1H NMR characterization of dynamic processes and ground state isomeric ratios of imidazole complexes in their stopped exchange limiting spectra, readily correlate with DFT-guided interpretation of Ni-L rotational activation barriers. Full DFT characterization relates the orientation mainly to steric hindrance derived both from ligand and binding pocket. In the case of the imidazole ligands a minor electronic contribution derives from intramolecular electrostatic interactions (imidazole C-2 C-H[superscript delta]- - S[superscript delta]− interaction). Our group has firmly established the versatility of the (bme-daco)2−, (bme-dach)2−, and (ema)4− ligands to accommodate a number of metals (M = Ni, Zn, Cu, and Fe), and have demonstrated reactivity of such N2S2M complexes occurs predominately at the S-thiolate sites. As vanadium is of interest for its biological, pharmacological and spectroscopic/analytical probe abilities, vanadyl analogues were explored as mimics of possible chelates formed from Cys-X-Cys binding sites in vivo. The structural and electronic changes from the incorporation of V=O2 in such dianionic and tetraanionic N2S2 binding pockets is investigated and compared to Ni2+ and Zn2+ in similar N2S2 environments. The nucleophilicity of the S-thiolate in these systems is explored with alkylating agents and W(CO)x. Furthermore, the vanadyl interaction with the CGC peptide, the biological analogue of the tetraanionic N2S2 ligand, was produced and characterized by EPR; its W(CO)x adducts were indentified by [upsilon](CO) infrared spectroscopy.

Book Molecular Electrostatic Potentials

Download or read book Molecular Electrostatic Potentials written by J.S. Murray and published by Elsevier. This book was released on 1996-11-22 with total page 681 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past 25 years, the molecular electrostatic potential has become firmly established as an effective guide to molecular interactions. With the recent advances in computational technology, it is currently being applied to a variety of important chemical and biological systems. Its range of applicability has expanded from primarily a focus on sites for electrophilic and nucleophilic attack to now include solvent effects, studies of zeolite, molecular cluster and crystal behavior, and the correlation and prediction of a wide range of macroscopic properties. Moreover, the increasing prominence of density functional theory has raised the molecular electrostatic potential to a new stature on a more fundamental conceptual level. It is rigorously defined in terms of the electron density, and has very interesting topological characteristics since it explicitly reflects opposing contributions from the nuclei and the electrons. This volume opens with a survey chapter by one of the original pioneers of the use of the electrostatic potential in studies of chemical reactivity, Jacopo Tomasi. Though the flow of the succeeding chapters is not stringently defined, the overall trend is that the emphasis changes gradually from methodology to applications. Chapters discussing more theoretical topics are placed near the end. Readers will find the wide variety of topics provided by an international group of authors both convincing and useful.

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 Nickel II Pincer Complexes Supported by 2 6 Bis 3 5 Ditolyl 2 Pyrrolyl Pyridine

Download or read book Nickel II Pincer Complexes Supported by 2 6 Bis 3 5 Ditolyl 2 Pyrrolyl Pyridine written by Abhijit Pramanik and published by . This book was released on 2015 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ni(II) pincer complexes are among the most important and useful compounds in homogeneous catalysis. Significant advancement has been made in this field in recent years. Many Ni(II) pincer complexes have been prepared and utilized in various catalytic reactions e.g. cross coupling reactions, C-H activation, carbon dioxide activation etc. Still, nickel(II) complexes supported by the pincer ligand with three nitrogen donors are relatively less explored and catalytic applications with those complexes are scarce in literature. This thesis describes the synthesis of a new pyrrolyl pyridine based pincer ligand and its Ni(II) complexes. The pyrrolyl pyridine pincer ligand, a relatively new class of dianionic, tridentate, nitrogen-based ligands in coordination chemistry, was prepared starting with a modified method for the synthesis of pyrrolyl pyridine. This modified procedure is simpler, less time consuming making it cheaper than the classical method and provides 2,6-bis(3,5-ditolyl-2-pyrrolyl)pyridine in good yields. Reaction of its potassium salt with Ni(OTf)2 resulted in three different stable nickel(II) pincer complexes. The novel nickel(II) pincer complexes were fully characterized by 1H NMR spectroscopy, 13C NMR spectroscopy, infrared spectroscopy and high resolution mass spectrometry. The X-ray crystal structures of the new ligand and metal complexes have been described.