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Book Synthesis and Studies of Mo and W Complexes for 2N Reduction

Download or read book Synthesis and Studies of Mo and W Complexes for 2N Reduction written by Jia Min Chin and published by . This book was released on 2010 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of monopyrroletriamine ligands [Arpyr(Ar')2]H3 of the form ArC4H2NHCH2N(CH2CH2NHAr')2 (Ar = 2,4,6-mesityl (Mes), 2,4,6-triisopropylphenyl (TRIP); Ar' = C6F5, 2-tolyl (o-tol), naphthyl, 3,5-(2,4,6-triisopropylphenyl)phenyl (HIPT), 3,5- dimethylphenyl, 3,5-di-tert-butylphenyl were synthesized. [Mespyr(C6F5)2]MoCl, ([Mespyr(C6F5)2]Mo = MesitylC4H2NCH2N(CH2CH2NC6F5)2) was prepared by reaction of [Mespyr(C6F5)2]H3 with MoCl4(THF)2 and base and [Mespyr(3,5-t-Bu)2]MoCl and [Mespyr(3,5- Me)2]MoCl (3,5-t-Bu=3,5-di-tert-butylphenyl, Me = 3,5-dimethylphenyl) were synthesized likewise. All three monochlorides are paramagnetic. [Mespyr(C6F5)2]MoNMe2, [[Mespyr(otol) 2]MoNMe2, [Mespyr(3,5-t-Bu)2]MoNMe2, [Mespyr(3,5-Me)2]MoNMe2 were synthesized by reaction of the ligands with Mo(NMe2)4. The resulting compounds are diamagnetic and range in color from teal blue to emerald green. These low spin monodimethylamide complexes exist in rapid equilibria with their high spin forms. [Mespyr(C6F5)2]MoN and [Mespyr(3,5-t-Bu)2]MoN were synthesized by reaction of their respective monochlorides with NaN3 and are yellow diamagnetic species. Reaction of [Mespyr(3,5-t-Bu)2]MoN with Et3OBF4 leads to {[Mespyr(3,5- t-Bu)2]MoNEt}BF4, also a diamagnetic yellow species. [Mespyr(C6F5)2]MoOTf is synthesized by the reaction of [Mespyr(C6F5)2]MoCl with AgOTf. Reduction of [Mespyr(3,5-t-Bu)2]MoCl with Na under N2 led to [Mespyr(3,5-t-Bu)2]MoNNNa(THF)x, several species with varying numbers of THF coordination, x. A single species can be obtained when [Mespyr(3,5-t- Bu)2]MoNNNa(THF)x is reacted with either NBu4Cl or 15-crown-5 ether to yield purple green 4 {[Mespyr(3,5-t-Bu)2]MoNN}NBu4 or [Mespyr(3,5-t-Bu)2]MoNNNa(15-c-5). All the diazenide species are diamagnetic. Oxidation of the diazenide with AgOTf yields [Mespyr(3,5-t- Bu)2]Mo(N2). [Mespyr(3,5-t-Bu)2]Mo(CO) is synthesized by exposure of [Mespyr(3,5-t- Bu)2]Mo(N2) to CO. Reaction of [Mespyr(3,5-t-Bu)2]MoCl with NaBPh4 and NH3 yields {[Mespyr(3,5-t-Bu)2]Mo(NH3)}BPh4. Catalytic runs employing [Mespyr(3,5-t-Bu)2]MoN as the catalyst yielded one equivalent of NH3. A triamidoamine ligand [(HIPTNCH2CH2CH2)3N]3- was synthesized and metalated with MoCl4(THF)2 to produce [(HIPTNCH2CH2CH2)3N]MoCl ([HIPTtrpn]MoCl). Reduction of [HIPTtrpn]MoCl by KC8 under an atmosphere of dinitrogen leads to the green species [HIPTtrpn]MoNNK which can be oxidized by ZnCl2(dioxane) to produce [HIPTtrpn]Mo(N2). Other complexes synthesized include {[HIPTtrpn]Mo(NH3)}+ salts and [HIPTtrpn]Mo(CO). Xray studies were carried out on [HIPTtrpn]MoN and {[HIPTtrpn]Mo(NH3)}BAr'4. This system is not catalytic for the reduction of dinitrogen to ammonia and studies were carried out to elucidate the reasons. Oxidation studies were carried out on [HIPTN3N]Mo(N2) and [HIPTN3N]W(N2) ([HIPTN3N] = [(HIPTNCH2CH2)3N]3- ). The rate of conversion of [HIPTN3N]Mo(NH3) to [HIPTN3N]Mo(N2) was studied and found to be increased in the presence of BPh3. [HIPTN3N]Mo(N2) conversion to [HIPTN3N]Mo(CO) was found to be dependent on CO pressure. Protonation studies of [HIPTN3N]Mo(N2) were also carried out. Studies of [HIPTN3N]MoNNH decomposition showed that decomposition is not base-catalyzed. [HIPTN3N]W(CO) was synthesized by exposure of [HIPTN3N]W(N2) to CO. It is a green, paramagnetic compound and its use as a standard (for determining relative concentrations of other compounds in the IR sample) in IR spectroscopic studies appears to be promising. [HIPTN3N]MoCNH2 was synthesized by addition of acid and reducing agent to [HIPTN3N]MoCN and is a yellow, diamagnetic compound. Two triamidophosphine ligands, triHIPTamine and tri-n-Buamine were synthesized. Metalation of Zr(NMe2)4 with these ligands leads to formation of pn3HIPTZrNMe2 and pn3-n- BuZrNMe2, both diamagnetic, pale yellow complexes.

Book Hydrazido 2 Complexes of Molybdenum and Tungsten

Download or read book Hydrazido 2 Complexes of Molybdenum and Tungsten written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this work was to examine in closer detail the reduction of dinitrogen coordinated to molybdenum and tungsten and in particular the reactivity of hydrazido(2-) complexes. A brief introduction to nitrogen fixation is presented in Chapter 1 and chemical models of biological nitrogen fixation are discussed. The influence of ligand environment on the further reactions of hydrazido(2-) complexes is the subject of Chapter 2 whilst Chapter 3 describes the isolation of novel hydrido-, hydrazido(2-) complexes of tungsten and the X-ray structure of [WCl3(NNH2) - (PMe2Ph)2] Recent applications of 15 N nuclear magnetic resonance spectroscopy in coordination chemistry are reviewed in Chapter 4 introducing results of spectroscopic studies of 15N-labelled dinitrogen and hydrazido(2-) complexes. Attempts to prepare novel hydrazido(2-) complexes of tungsten are described in Chapter 5. A discussion of the results presented in Chapter's 2-5 is given in Chapter 6.

Book The Chemistry of Tungsten and Molybdenum Diazene Complexes

Download or read book The Chemistry of Tungsten and Molybdenum Diazene Complexes written by Milton Rudolph Smith and published by . This book was released on 1990 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Molybdenum and Tungsten Complexes of Dinitrogen CO and Isocyanides that Contain Aryl substituted Triamidoamine Ligands

Download or read book Molybdenum and Tungsten Complexes of Dinitrogen CO and Isocyanides that Contain Aryl substituted Triamidoamine Ligands written by George Emil Greco and published by . This book was released on 2000 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book The Coordination Chemistry of Hydrazide and Diazenide Complexes of Rhenium

Download or read book The Coordination Chemistry of Hydrazide and Diazenide Complexes of Rhenium written by Suzanne J. Parrott and published by . This book was released on 1992 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Transition Metal Dinitrogen Complexes

Download or read book Transition Metal Dinitrogen Complexes written by Yoshiaki Nishibayashi and published by John Wiley & Sons. This book was released on 2019-01-25 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive book that explores nitrogen fixation by using transition metal-dinitrogen complexes Nitrogen fixation is one of the most prominent fields of research in chemistry. This book puts the focus on the development of catalytic ammonia formation from nitrogen gas under ambient reaction conditions that has been recently repowered by some research groups. With contributions from noted experts in the field, Transition Metal-Dinitrogen Complexes offers an important guide and comprehensive resource to the most recent research and developments on the topic of nitrogen fixation by using transition metal-dinitrogen. The book is filled with the information needed to understand the synthesis of transition metal-dinitrogen complexes and their reactivity. This important book: -Offers a resource for understanding nitrogen fixation chemistry that is essential for explosives, pharmaceuticals, dyes, and all forms of life -Includes the information needed for anyone interested in the field of nitrogen fixation by using transition metal-dinitrogen complexes -Contains state-of-the-art research on synthesis of transition metal-dinitrogen complexes and their reactivity in nitrogen fixation -Incorporates contributions from well-known specialists and experts with an editor who is an innovator in the field of dinitrogen chemistry Written for chemists and scientists with an interest in nitrogen fixation, Transition Metal-Dinitrogen Complexes is a must-have resource to the burgeoning field of nitrogen fixation by using transition metal-dinitrogen complexes.

Book Catalysts for Nitrogen Fixation

Download or read book Catalysts for Nitrogen Fixation written by Barry E. Smith and published by Springer Science & Business Media. This book was released on 2004-08-26 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biological nitrogen fixation provides more than 50% of the total annual input of the essential element nitrogen to world agriculture. Thus, it is of immense agronomic importance and critical to food supplies, particularly in developing countries. This book, with chapters authored by internationally renowned experts, provides a comprehensive and detailed account of the fascinating history of the process - including the surprising discoveries of molybdenum-independent nitrogenases and superoxide-dependent nitrogenase; a review of Man's attempts to emulate the biological process - most successfully with the commercially dominant Haber-Bosch process; and the current state of the understanding art with respect to the enzymes - called nitrogenases - responsible for biological nitrogen fixation. The initial chapters use a historical approach to the biological and industrial processes, followed by an overview of assay methodologies. The next set of chapters focuses on the classical enzyme, the molybdenum nitrogenase, and details its biosynthesis, structure, composition, and mechanism of action as well as detailing both how variants of its two component proteins are constructed by recombinant DNA technology and how computational techniques are being applied. The sophisticated chemical modelling of the metal-containing clusters in the enzyme is reviewed next, followed by a description of the two molybdenum-independent nitrogenases - first, the vanadium-containing enzyme and then the iron-only nitrogenase - together with some thoughts as to why they exist! Then follows an up-to-date treatment of the clearly "non-classical" properties of the superoxide-dependent nitrogenase, which more closely resembles molybdenum-containing hydroxylases and related enzymes, like nitrate reductase, that it does the other nitrogenases. Each chapter contains an extensive list of references. This book is the self-contained first volume of a comprehensive seven-volume series. No other available work provides the up-to-date and in-depth coverage of this series and this volume. This book is intended to serve as an indispensable reference work for all scientists working in this area, including agriculture and the closely related metals-in-biology area; to assist students to enter this challenging area of research; and to provide science administrators easy access to vital relevant information.

Book Preparation and Characterization of High Oxidation State Tungsten and Molybdenum Complexes Containing Phenoxide Thiolate Alkyl Cyclopentadienyl and Dinitrogen Ligands

Download or read book Preparation and Characterization of High Oxidation State Tungsten and Molybdenum Complexes Containing Phenoxide Thiolate Alkyl Cyclopentadienyl and Dinitrogen Ligands written by Richard Michael Kolodziej and published by . This book was released on 1989 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Dithiocarbamate and related complexes of rhenium molybdenum and tungsten

Download or read book Dithiocarbamate and related complexes of rhenium molybdenum and tungsten written by John Frederick Rowbottom and published by . This book was released on 1974 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Nitrogen Donor Complexes of Molybdenum and Tungsten and New Routes to Bis 1 2 Tris 1 2 3 Substituted Ferrocenes

Download or read book Nitrogen Donor Complexes of Molybdenum and Tungsten and New Routes to Bis 1 2 Tris 1 2 3 Substituted Ferrocenes written by Kevin Martin Fortune and published by . This book was released on 2004 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Mono dinitrogen Complexes of Molybdenum that Produce Ammonia and Hydrazine

Download or read book Mono dinitrogen Complexes of Molybdenum that Produce Ammonia and Hydrazine written by Robert Clayton Tisdale and published by . This book was released on 1986 with total page 870 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Complexes of Molybdenum Iron and Cobalt as Catalysts for the Activation of Dinitrogen

Download or read book Complexes of Molybdenum Iron and Cobalt as Catalysts for the Activation of Dinitrogen written by David Allen Parker and published by . This book was released on 1971 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: