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Theoretical Studies On Intermolecular Versus Intramolecular Carbon Hydrogen Bond Activation In Rhodium Iridium And Zirconium Complexes And On The Ethene To Hydridovinyl Interconversion In Rhodium And Iridium Complexes
Download Theoretical Studies On Intermolecular Versus Intramolecular Carbon Hydrogen Bond Activation In Rhodium Iridium And Zirconium Complexes And On The Ethene To Hydridovinyl Interconversion In Rhodium And Iridium Complexes full books in PDF, epub, and Kindle. Read online Theoretical Studies On Intermolecular Versus Intramolecular Carbon Hydrogen Bond Activation In Rhodium Iridium And Zirconium Complexes And On The Ethene To Hydridovinyl Interconversion In Rhodium And Iridium Complexes ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Theoretical Studies on Intermolecular Versus Intramolecular Carbon-hydrogen Bond Activation in Rhodium, Iridium, and Zirconium Complexes, and on the Ethene to Hydridovinyl Interconversion in Rhodium and Iridium Complexes by : Rogelio Jimenez-Catano
Download or read book Theoretical Studies on Intermolecular Versus Intramolecular Carbon-hydrogen Bond Activation in Rhodium, Iridium, and Zirconium Complexes, and on the Ethene to Hydridovinyl Interconversion in Rhodium and Iridium Complexes written by Rogelio Jimenez-Catano and published by . This book was released on 1995 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Dissertation Abstracts International by :
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1996 with total page 844 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis American Doctoral Dissertations by :
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1995 with total page 896 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Intermolecular and Intramolecular Carbon-hydrogen Bond Activation with Pentamethylcyclopentadienyl-rhodium-phosphine Complexes by : Valerie L. Chandler
Download or read book Intermolecular and Intramolecular Carbon-hydrogen Bond Activation with Pentamethylcyclopentadienyl-rhodium-phosphine Complexes written by Valerie L. Chandler and published by . This book was released on 1989 with total page 938 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Centre de recherche de l'Univ. de Paris VIII, Vincennes. Groupe Cultures, idéologies et sociétés des XIXe et XXe siècles by :
Download or read book Centre de recherche de l'Univ. de Paris VIII, Vincennes. Groupe Cultures, idéologies et sociétés des XIXe et XXe siècles written by and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthetic and Mechanistic Studies of Carbon-hydrogen Bond Activation by Iridium(III) Complexes and Development of a Transition Metal Catalyzed Alkene Aziridination Reaction by : Peter James Alaimo
Download or read book Synthetic and Mechanistic Studies of Carbon-hydrogen Bond Activation by Iridium(III) Complexes and Development of a Transition Metal Catalyzed Alkene Aziridination Reaction written by Peter James Alaimo and published by . This book was released on 1999 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Mechanism of Carbon-hydrogen Bond Activation with Hard-ligated Rhodium Complexes by : Chunming Wang
Download or read book The Mechanism of Carbon-hydrogen Bond Activation with Hard-ligated Rhodium Complexes written by Chunming Wang and published by . This book was released on 1994 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis I. Carbon Hydrogen Bond Activation by Iridium(III) and Rhodium(III) ; II. The Self-assembly of Supra-molecular Squares Via Platinum(II) and Palladium(II) Metal Triflates by : Danh H. Cao
Download or read book I. Carbon Hydrogen Bond Activation by Iridium(III) and Rhodium(III) ; II. The Self-assembly of Supra-molecular Squares Via Platinum(II) and Palladium(II) Metal Triflates written by Danh H. Cao and published by . This book was released on 1996 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Iridium(I) Complexes for the Functionalisation of Carbon-hydrogen Bonds by : Renan Zorzatto
Download or read book Iridium(I) Complexes for the Functionalisation of Carbon-hydrogen Bonds written by Renan Zorzatto and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of catalytic systems for the functionalisation of carbon-hydrogen bonds has been an intensive area of research for the last 5 decades. In this context, transition metal complexes play a crucial role in reaction discovery, mechanistic evaluation and synthetic applications. In the Kerr group, this technology has been explored in the context of hydrogen isotope exchange, resulting in the development of highly active iridium(I) complexes bearing phosphines and NHC ligands. Despite their broad functional group compatibility, existing methods for isotope exchange are ineffective in the labelling of sterically encumbered directing groups. Hence, in the first chapter we investigate the synthesis of three new iridium(I) complexes bearing chelating phosphine-functionalised NHC ligands, and their application in the isotope exchange of sterically hindered carbamates. Our initial studies revealed high catalytic efficiency and tolerance for steric encumbrance, prompting us to perform a combined theoretical and experimental investigation of the reaction mechanism.Therefore, by conducting DFT calculations and kinetic experiments, we were able to identify a rich dynamic behaviour in solution and ultimately propose a reaction mechanism. Additionally, our interest in the activation of carbon-hydrogen bonds resulted in the exploration of a theoretical model for the prediction of enthalpies of activation, resulting in the identification of relevant electronic and steric descriptors.From the knowledge gathered in our initial studies, the second chapter describes the application of our novel iridium catalysts in the functionalisation of carbon-hydrogen bonds in the context of hydroarylation of olefins. Thus, we identified carboxylic acids as suitable directing groups for this transformation and employed Design of Experiments to optimise the reaction conditions. Synthetic studies were focused on the preparation of 14 substrates, enabling quick assessment of the capabilities and limitations of this reaction. These investigations resulted in a synthetic method suitable for the synthesis of bi- and tricycles featuring tertiary and quaternary benzylic stereocentres in a racemic fashion.Finally, we investigated the mechanism of this process by DFT calculations, which led us to identify a plausible reaction pathway which should guide future kinetic evaluations.
Book Synopsis Carbon-hydrogen Bond Activation and Catalytic Hydrocarbon Functionalization with Rhodium Isocyanide Complexes by : Edward T. Hessell
Download or read book Carbon-hydrogen Bond Activation and Catalytic Hydrocarbon Functionalization with Rhodium Isocyanide Complexes written by Edward T. Hessell and published by . This book was released on 1991 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Development of Carbon-hydrogen Bond Activation Using Cationic Rhodium and Iridium Catalysts by : 土釜恭直
Download or read book Development of Carbon-hydrogen Bond Activation Using Cationic Rhodium and Iridium Catalysts written by 土釜恭直 and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis of Electrophilic Rhodium and Iridium Complexes and Investigation of Reactivity for C-H Bond Activation and Functionalization by : Kate E. Allen
Download or read book Synthesis of Electrophilic Rhodium and Iridium Complexes and Investigation of Reactivity for C-H Bond Activation and Functionalization written by Kate E. Allen and published by . This book was released on 2013 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct methods for the transformation of alkanes into alcohols, alkenes, amines and other functionalized products would have a great impact on industrial processes. In this thesis the work described is aimed at developing electrophilic Rh and Ir systems to promote C-H bond activation and functionalization of alkanes and arenes. Several approaches have been taken to prepare the target complex [Tp*Ir(OH2)3]+ (Tp* = hydridotris(3,5-dimethylpyrazoyl)borate). While this species has not been synthesized, C-N coupling between ethylene and N-iodosuccinimide has been observed during the course of this study and is promoted by Tp*Ir(C2H4)2. Electrophilic Rh and Ir complexes bearing dimethylbutadiene (DMB) ligands have been found to be poor species for C-H activation due to low stability at elevated temperatures. Interestingly, formation of the unique five-coordinate [(DMB)Ir(COE)Cl]2 dimer has been observed. Alkane dehydrogenation using ([superscript dm]Phebox)Ir(OAc)2(OH2) ([superscript dm]Phebox = 2,6-bis(4,4-dimethyloxazolinyl)-3,5-dimethylphenyl) is promoted at 200 °C and results in quantitative formation of olefin and (([superscript dm]Phebox)Ir(OAc)H. At early reaction times 1-octene is the major product, supporting terminal C-H activation by the Ir center. Oxygen can be utilized in this system as a hydrogen acceptor to promote regeneration of the Ir bisacetate species at room temperature. This is the first example of regeneration of a complex for dehydrogenation using oxygen. Unfortunately, the system is not catalytic as the reaction with oxygen is not compatible with the high temperatures required for C-H bond activation. In order to expand the number of examples of alkane dehydrogenation at Ir[superscript III] centers, a second system utilizing the [superscript tBu]NOCON ([superscript tBu]NOCON = 4,6-di-tert-butyl-(1,3-bis(2-pyridyloxy)benzene)) pincer ligand has been developed. Complexes ([superscript tBu] NOCON)M(OAc)2OH2 (M = Rh or Ir) were synthesized and explored for C-H bond functionalization. The Ir analogue promotes alkane dehydrogenation at 200 °C, but is not stable under the reaction conditions. Arene functionalization has also been explored using Ir-aryl complexes. The product of benzene C-H activation, (Phebox)Ir(OAc)Ph has been investigated for arene functionalization using hypervalent iodide reagents and CO. Reactions utilizing C6F5I(TFA)2 are promising and may potentially yield functionalized arene. Coordination of CO to the Ir center has been observed and isomerization of the trans product, ([superscript dm]Phebox)Ir(CO)(OAc)Ph, occurs at room temperature to yield the cis isomer ([superscript dm] Phebox)Ir(OAc)(CO)Ph.
Book Synopsis Activation of Carbon-hydrogen Bonds in Alkanes and Other Organic Molecules Using Organotransition Metal Complexes by :
Download or read book Activation of Carbon-hydrogen Bonds in Alkanes and Other Organic Molecules Using Organotransition Metal Complexes written by and published by . This book was released on 1991 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have recently begun to investigate the interaction of C-H activating iridium and rhodium complexes with functionalized organic molecules, to determine the effect of functional groups on the process, as well as to investigate the propensity of Ir and Rh to insert into C-H versus other types of X-H bonds. Recent experiments have demonstrated that xenon liquefied at -70°C and 10 atm pressure serves as an inert solvent for the C-H oxidative addition reaction. We have been able to prepare and isolate, for the first time, C-H oxidative addition products formed from high-melting solid substrates such as naphthalene, adamantane, and even cubane; the latter case represents the first observation of C-H oxidative addition at a tertiary C-H bond. Liquid xenon has also allowed us to carry out more conveniently the C-H oxidative addition reactions of low-boiling gases that are difficult to liquefy, such as methane. Recently we have also been able to carry out analogous studies in the gas phase. Under these conditions, ''naked'' rather than solvated Cp*Rh(CO) is formed, and this species reacts with cyclohexane at nearly gas-kinetic rates. Under the conditions, collision between Cp*Rh(CO) and cyclohexane is the slowest step in the overall C-H activation process. In contrast, in solution association of solvent with free Cp*Rh(CO) is so rapid that the step involving C-H bond cleavage in the coordinated alkane complex becomes rate-determining. 3 refs., 5 figs.
Book Synopsis C-H Bond Activation in Iridium Complexes by : Jack Scott Wiley
Download or read book C-H Bond Activation in Iridium Complexes written by Jack Scott Wiley and published by . This book was released on 1999 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Studies of Carbon-hydrogen and Silicon-hydrogen Bond Activation by Early Transition Metal Complexes by : Paige Marie Morse
Download or read book Studies of Carbon-hydrogen and Silicon-hydrogen Bond Activation by Early Transition Metal Complexes written by Paige Marie Morse and published by . This book was released on 1990 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compounds that contain early transition metals particularly titanium, vanadium, and chromium, are used as catalysts for olefin polymerization in the Ziegler-Natta and Phillips processes. The key intermediates in these catalysts are thought to be six-coordinate metal alkyl/olefin complexes. The synthesis and study of early transition metal alkyl complexes as models of these catalytic centers can provide insight into the mechanism of polymerization processes.
Book Synopsis Development of Novel Rhodium and Iridium Complexes with a Fac-chelating Ligand for Electrophilic C-H Activation by : Jennifer Lee Rhinehart
Download or read book Development of Novel Rhodium and Iridium Complexes with a Fac-chelating Ligand for Electrophilic C-H Activation written by Jennifer Lee Rhinehart and published by . This book was released on 2011 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Several new bis-3,5(dimethylpyrazol-1-yl)acetate rhodium and iridium complexes were synthesized from MCl3?H2O. [Rh(bdmpza)Cl3]- was isolated with three different cations, lithium, sodium and tetraethylamonium, to obtain a full characterization profile. Analogously, [Ir(bdmpza)Cl3]- was isolated with two different cations, lithium and sodium, and characterized by 1H NMR, 13C NMR, elemental analysis and X-ray crystal structure determination. A neutral rhodium complex, [Rh(bdmpza)Cl2(py)], was also isolated as two isomers by addition of pyridine. Reaction of [Rh(bdmpza)Cl3]- and [Rh(bdmpza)Cl2(py)] with dimethylzinc afforded three new complexes, [Rh(bdmpza)Cl2(Me)]-, [Rh(bdmpza)Cl(Me)2]- and [Rh(bdmpza)Cl(Me)(py)]. Stoichiometric and catalytic C-H activation of benzene was investigated for these new rhodium methyl complexes. Novel rhodium and iridium precatalysts catalysts, [Rh(bdmpza)Cl3]- Na+, [Ir(bdmpza)Cl3]- Na+ and [Rh(bdmpza)Cl2(py)], were subjected to H/D exchange conditions with benzene and deuterated trifluoroacetic acid, acetic acid and methanol in the presence of a halide abstractor. Optimum conditions of silver triflate, deuterated trifuoroacetic acid, 100°C and 24 hours were identified to conduct arene H/D exchange studies. Most arenes investigated showed modest H/D exchange in the ring, while branched [beta]-sp3C-H bonds also showed affinity for H/D exchange. Mechanistic studies of [beta]-sp3C-H H/D exchange were carried out, including synthesis of [Rh(bdmpz)Cl3(py)], which does not contain the pendant acetate group"--Leaf vi.
Book Synopsis Bifunctional Rhodium and Iridium Platforms Towards C-H Activation by : Travis John Morrow
Download or read book Bifunctional Rhodium and Iridium Platforms Towards C-H Activation written by Travis John Morrow and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Pendent nucleophiles are essential partners in the cleavage and formation of bonds with hydrogen (e.g. protonation/deprotonation), but binding of the pendent group to the metal and the potential trapping of complexes in inactive states are a significant problem. The dipyridylmethane-based ligand framework bis(2-pyridyl)-N-pyrrolidinomethane([superscript]R,pyrCPy2), bearing a hemilabile pyrrolidine moiety, has been synthesized and complexes of the type [([superscript]R,pyrCPy2)M(COD)]X (COD = 1,5-cyclooctadiene) were prepared. The solution-phase ligand dynamics and relative protonation preferences were investigated via1H NMR spectroscopy; although favorable, pendent amine binding does not kinetically inhibit pendent base protonation. Protonation at the metal (with concomitant pyrrolidine binding) has been found to be favorable for Ir, whereas N-protonation is favorable for Rh. DFT calculations predict that the RhIII hydrides have much higher relative acidities than their Ir congeners (∆pK[subscript]a ≃ 7–8 in CH2Cl2), and are also more acidic than the strong acid[H(OEt2)2][B(C6F5)4]. The second part of this dissertation examines oxidative addition of carbon-halogen bonds at transition metals, which typically follow either a two-electron pathway (concerted MR/M-X formation) or a radical chain pathway (stepwise M-R/M-X formation). When the reactive metal species is generated slowly, however, both mechanisms can compete to yield unexpected reactivity paths. The present report highlights the synthesis of rhodiummethylidenes from chloroalkanes (e.g. CH2Cl2 and CHCl3) at POP-pincer frameworks(e.g. POP = 4,6-bis(di-tert-butylphosphino)dibenzo[b,d]furan) via a cascade of halide abstraction and electron transfer steps. Experimental and computational studies are covered that support our proposed mechanism, including characterization of important reaction intermediates. The overall transformation presented represents a route towards reactive metal alkylidenes using milder and less-reactive carbenoid precursors than what is presently used.
