Download or read book Coordination Chemistry of Late Transition Metals with PCP Ligands written by Daniel Olsson and published by . This book was released on 2007 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comprehensive Coordination Chemistry II Transition metal groups 7 and 8 written by Jon A. McCleverty and published by Pergamon. This book was released on 2004 with total page 906 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Late Transition metal Complexes Supported by Pincer Ligands written by Wilson D. Bailey and published by . This book was released on 2016 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: Late transition-metal pincer complexes of primarily palladium(II) and platinum(II) have been investigated for their application as catalysts in partial oxidation reactions. The epoxidation of higher olefins using molecular oxygen as the oxidant has been targeted, and the individual reaction steps needed to accomplish this overall transformation are described herein, including: (1) hydrogenolysis of a metal hydroxide (M-OH) species to yield a metal hydride (M-H), (2) insertion of O2 into the M-H bond to form a metal hydroperoxide (M-OOH), and (3) O-atom transfer from the M-OOH to epoxides, yielding a M-OH and completing the catalytic cycle. Previous results from our group on these individual transformations using (tBuPCP)Pd and (tBuPCO)Pd fragments are also reviewed. The requirements for O2 insertion into PdII and PtII hydrides are discussed. An array of cationic, neutral, and anionic Pd-H and Pt-H complexes supported by a tBuPNP backbone were synthesized and evaluated for O2 insertion (tBuPNP = 2,6-bis-(di-tbutylphosphinomethyl)pyridine). Metal-ligand cooperation was observed in the activation of H2 to form neutral hydride complexes. The effect of ligand protonation/deprotonation on the trans influence experienced by the hydride ligand was investigated. No reaction with O2 was observed with the cationic hydrides, while the neutral and anionic forms reacted with O2 at the tBuPNP backbone. The synthesis and characterization of mono- and dinuclear Pd-OH complexes supported by a PCNR pincer ligand (PCNR = (1-(3-((di-tert-butylphosphino)methyl)phenyl)-1H-5-R-pyrazole), R = H, Me) is presented. When R = H, ligand pyrazole "rollover" C-H activation was observed, forming a mixed ligand (PCNH)Pd(μ-OH)Pd(PCC) dinuclear structure. This "rollover" was investigated using DFT computations. The mono- and dinuclear hydroxide species were evaluated for hydrogenolysis. The dinuclear compounds {[(PCNR)Pd]2(μ-OH)}[OTf] reacted under an H2 atmosphere to yield the corresponding dinuclear hydrides {[(PCNR)Pd]2(μ-H)}[OTf]. A mechanistic study on the hydrogenolysis of the μ-bridged hydroxide {[(PCNMe)Pd]2(μ-OH)}[OTf] revealed first order kinetics in both [Pd] and [H2]. Terminal hydrides were not detected, and reduction of the mononuclear hydroxide complexes (PCNR)Pd-OH to Pd0 was observed under H2. The reduction was proposed to proceed through displacement of the pyrazole arm, and was examined by DFT computations. Lastly, a new strategy to promote O-atom transfer from M-OOH to epoxides, the final step in the targeted catalytic cycle, is proposed. Preliminary studies on NNNPyz, NNNEt, and NNMe ligated PdII and PtII are discussed (NNNPyz = 2,6-bis(5-tbutyl-1H-pyrazol-3-yl)pyridine; NNNEt = 2-(5-tbutyl-1H-pyrazol-3-yl)-6-(diethylaminomethyl)pyridine; NNMe = 2-(5-tBu-1H-pyrazol-3-yl)-6-methylpyridine). The NNNPyz ligand, containing two acidic sites in proximity to the fourth site in the square plane, was found to protonate M-O2 complexes, chelate to the metal center and oxidize phosphine substrates. Similar reactivity was observed with NNNEt and NNMe, however hemilability of these ligands resulted in undesired coordination modes.
Download or read book Comprehensive Coordination Chemistry II written by J. A. McCleverty and published by Elsevier Science. This book was released on 2004 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Coordination Chemistry II (CCC II) is the sequel to what has become a classic in the field, Comprehensive Coordination Chemistry, published in 1987. CCC II builds on the first and surveys new developments authoritatively in over 200 newly comissioned chapters, with an emphasis on current trends in biology, materials science and other areas of contemporary scientific interest.
Download or read book Pincer Compounds written by David Morales-Morales and published by Elsevier. This book was released on 2018-04-11 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pincer Compounds: Chemistry and Applications offers valuable state-of-the-art coverage highlighting highly active areas of research—from mechanistic work to synthesis and characterization. The book focuses on small molecule activation chemistry (particularly H2 and hydrogenation), earth abundant metals (such as Fe), actinides, carbene-pincers, chiral catalysis, and alternative solvent usage. The book covers the current state of the field, featuring chapters from renowned contributors, covering four continents and ranging from still-active pioneers to new names emerging as creative strong contributors to this fascinating and promising area. Over a decade since the publication of Morales-Morales and Jensen’s The Chemistry of Pincer Compounds (Elsevier 2007), research in this unique area has flourished, finding a plethora of applications in almost every single branch of chemistry—from their traditional application as very robust and active catalysts all the way to potential biological and pharmaceutical applications. Describes the chemistry and applications of this important class of organometallic and coordination compounds Includes contributions from global leaders in the field, featuring pioneers in the area as well as emerging experts conducting exciting research on pincer complexes Highlights areas of promising and active research, including small molecule activation, earth abundant metals, and actinide chemistry
Download or read book Organometallic Pincer Chemistry written by Gerard van Koten and published by Springer. This book was released on 2012-09-17 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gerard van Koten: The Mono-anionic ECE-Pincer Ligand - a Versatile Privileged Ligand Platform: General Considerations.- Elena Poverenov, David Milstein: Non-Innocent Behavior of PCP and PCN Pincer Ligands of Late Metal Complexes.- Dean M. Roddick: Tuning of PCP Pincer Ligand Electronic and Steric Properties.- Gemma R. Freeman, J. A. Gareth Williams: Metal Complexes of Pincer Ligands: Excited States, Photochemistry, and Luminescence.- Davit Zargarian, Annie Castonguay, Denis M. Spasyuk: ECE-Type Pincer Complexes of Nickel.- Roman Jambor and Libor Dostál: The Chemistry of Pincer Complexes of 13 - 15 Main Group Elements.- Kálmán J. Szabo: Pincer Complexes as Catalysts in Organic Chemistry.- Jun-ichi Ito and Hisao Nishiyama: Optically Active Bis(oxazolinyl)phenyl Metal Complexes as Multi-potent Catalysts.- Anthony St. John, Karen I. Goldberg, and D. Michael Heinekey: Pincer Complexes as Catalysts for Amine Borane Dehydrogenation.- Dmitri Gelman and Ronit Romm: PC(sp3)P Transition Metal Pincer Complexes: Properties and Catalytic Applications.- Jennifer Hawk and Steve Craig: Physical Applications of Pincer Complexes.
Download or read book Compounds of the Transition Elements Involving Metal Metal Bonds written by D. L. Kepert and published by Elsevier. This book was released on 2013-10-22 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compounds of the Transition Elements Involving Metal-Metal Bonds deals with compounds of the transition elements involving metal-metal bonds, with particular emphasis on metal-metal bonds in coordination compounds and organometallic complexes, halides, and oxides. Factors that influence the formation, stability, and properties of such compounds, as well as their application in various fields of chemistry and physics, are discussed. This book is divided into four sections and begins with a classification of metal-metal bonds and some of the physical and chemical methods used to study them, including X-ray crystallography, magnetic susceptibility and electron spin resonance, nuclear spin resonance, Mössbauer measurements, infrared and Raman spectroscopy, visible and ultraviolet spectroscopy, mass spectrometry, electrical conductivity, electrochemical methods, and chemical reactivity. Factors influencing the strength of metal-metal bonds in metals and compounds are also examined. The remaining sections deal with metal-metal bonds in coordination compounds and organometallic complexes, halides, and oxides. This monograph will be a useful resource for inorganic chemists.
Download or read book Transition Metal Complexes of Neutral Eta1 Carbon Ligands written by Remi Chauvin and published by Springer Science & Business Media. This book was released on 2010-01-12 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is part of a series that gives the broad scientific readership a comprehensive summary and critical overview of specific topics in the field of organometallic chemistry. This text focuses on transition metal complexes of neutral eta1-carbon ligands.
Download or read book Synthesis Structures and Characterization of Coordination Compounds with the Transition Metals Ni II Cu II Mn II Cr III Fe III Using Ligands Based on Iminodiacetic Acid and N heterocycles written by Maria Paula Juanico and published by Cuvillier Verlag. This book was released on 2003 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transition Metal Complexes with P N Ligands and Silylenes Synthesis and Catalytic Studies written by Eva Neumann and published by Cuvillier Verlag. This book was released on 2006-02-15 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: The term ligand [latin, ligare = bind] has its origin in coordination chemistry. It denotes a molecule that is able to bind to a metal center in most cases via one or several free electron pairs.[1] Ligands can be described by the number of electron-pair donor atoms as monodentate, bidentate, tridentate etc. ligands. The latter are also called chelating ligands [greek, chele = (crab’s) claw]. A typical classification of ligands is according to their electronic properties. They serve either as a σ-donating, σ-donating/π-accepting, or σ,π-donating/π-accepting ligands.[2] A more practical, often encountered approach is the classification of ligands according to their donor atoms, especially when larger molecules and molecules containing heteroatoms are regarded (compare 1.2). Coordination chemistry was already established in the 19th century. In 1893 Alfred Werner suggested an octahedral arrangement of ligands coordinated to a central metal ion for many compounds. This explained, for example, the appearance and reactivity of four different cobalt(III) complexes (Figure 1.1), when CoCl2 is dissolved in aqueous ammonia and then oxidized by air to the +3 oxidation state. The formulas of these complexes can be written as depicted in Figure 1.1. Werner’s work was rewarded with the Nobel prize in 1913.[3]
Download or read book Organometallic Chemistry Supported by the PNP Pincer Framework for Both Early and Late Transition Metals written by Christina Brammell Brammell and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Tridentate "pincer" ligands provide a unique balance of stability and reactivity in organometallic chemistry. The development of diarylamido-based PNP pincer ligands has led to many applications in catalysis, including the potential to facilitate unique chemical transformations at transition metal centers. The main objective of this thesis was to explore transition metal chemistry supported by the PNP pincer framework for both early and late transition metals. In Chapter I, the history behind the design and synthesis of pincer complexes is described. The advantages and disadvantages of various pincer ligands are reviewed to show the reasoning behind the synthesis of the PNP pincer framework. Chapter II discusses the synthesis of novel Hf and Ta complexes involving the PNP ligand. Reactions of (PNP)HfCl3 with large alkyl Grignards led to double alkylation and triple alkylation was achieved with methyl Grignard. (PNP)HfMe3 and (PNP)Hf(CH2SiMe3)2Cl displayed remarkably irregular coordination environments about hafnium, in contrast to the approximately octahedral structure of (PNP)HfCl3. (PNP)HfMe3 was found to be thermally stable at 75 °C, whereas thermolysis of (PNP)Hf(CH2SiMe3)2Cl under similar conditions led to a mixture of products. The major decomposition product is believed to be a Hf alkylidene complex on the basis of in situ NMR spectroscopic observations (e.g., [delta] 248.2 ppm in the 13C{1H} NMR spectrum).27 The reaction of (PNP)TaF4 with an excess of ethyl Grignard led primarily to the double alkylation product, (PNP)Ta(CH2CH3)2F2. Repeating this reaction in the presence of excess ethyl Grignard and dioxane resulted in the formation of an ethylene complex, (PNP)Ta(=CHCH3)(C2H4). In Chapter III, a C-C reductive elimination study is described comparing two pincer ligand scaffolds: Me(PNP) ligand and TH(PNP) ligand. The tied ligand has previously been found to be more sterically demanding than the untied ligand, which has allowed for faster N-C cleavage, faster oxidative addition and a more selective alkyne dimerization catalyst. This study reveals that the tied ligand complex, TH(PNP)Rh(C6H4CF3)(Ph), undergoes slower reductive elimination of p-Ph-C6H4CF3 (
Download or read book Synthesis of Multidentate PNE Ligands and Their Late Transition Metal Coordination Chemistry written by and published by . This book was released on 2007 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book PNP Pincer Ligands in Late Transition Metal Nitrido Chemistry and Gold Catalysis written by Vincent Vreeken and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coordination Compounds of the Transition Metals written by R. B. King and published by . This book was released on 1970 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: The base-catalyzed addition of phosphorus-hydrogen and arsenic-hydrogen bonds to the carbon-carbon multiple bonds in vinylphosphines and ethynylphosphines provides a useful new method for the synthesis of novel polytertiary phosphines and phosphine-arsines. Using this method the authors have prepared in large quantities and studied the coordination chemistry of the tritertiary phosphine ((C6H5)2PCH2CH2)2PC6H5, the two isomeric tetratertiary phosphines (C6H5)2PCH2CH2P(C6H5)CH2CH2P(C6H5)CH2CH2P(C6H5)2 and ((C6H5)2PCH2CH2)3P, and the hexatertiary phosphine ((C6H5)2PCH2CH2)2PCH2CH2P(CH2CH2P(C6H5)2)2. This preparative method also provides convenient syntheses of the mixed phosphine-arsines as (C6H5)2PCH2CH2As(C6H5)2. A similar base-catalyzed addition of (C6H5)2EH (E = P or As) to vinyl isocyanide gives the novel isocyanide derivatives (C6H5)2ECH2CH2NC (E = P or As). However, base-catalyzed addition of C6H5PH2 to vinyl isocyanide results in 1,4-addition to give the new phosphorus-carbon-nitrogen heterocycle 1-phenyl-4,5-dihydro-3-azaphosphole. This report also describes transition metal complexes of the ligands (C6H5)2PCCC6H5, (C6H5)2PCH2CCCH2P(C6H5)2, ((CH3)2N)3E (E = P or As), and (p-(CH3)2NC6H4)nP(C6H5)(3-n) (n =1, 2, and 3). (Author).
Download or read book PNP Pincer Ligands and Their Late Transition Metal Complexes in the Context of Strong Bond Activation and Catalysis written by Lei Fan and published by . This book was released on 2006 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Syntheses of Transition Metal Complexes written by Marek Matusz and published by . This book was released on 1984 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Early Transition Metal Complexes of Amine phenolate Ligands written by Edit Y. Tshuva and published by . This book was released on 2001 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt:
