Download or read book Synthesis Structural and Catalytic Studies of Some New Complexes of Molybdenum II and Tungsten II written by David James Muldoon and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthetic Structural and Catalytic Studies of Some New Complexes of Molybdenum II and Tungsten II written by David James Muldoon and published by . This book was released on 1994 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Investigation of Some New Complexes of Molybdenum II and Tungsten II Containing Sulphur Donor Ligands written by Sharman Donna Harris and published by . This book was released on 1995 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterisation of Some New Complexes of Molybdenum II and Tungsten II Containing Anionic and Neutral Sulphur Donor Ligands written by Alec Ian Clark and published by . This book was released on 1997 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterisation of Some New Complexes of Molybdenum II and Tungsten II Containing Anionic and Neutrual Sulphur Donor Ligands written by Alec Ian Clark and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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.
Download or read book Transition Metal Dinitrogen Complexes written by Yoshiaki Nishibayashi and published by John Wiley & Sons. This book was released on 2019-05-06 with total page 496 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.
Download or read book Ligand Variation in Molybdenum Imido Alkylidene Complexes written by Alejandro Gaston Lichtscheidl and published by . This book was released on 2012 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1. A general introduction is given. Chapter 2. The biscarboxylate species, Mo(NR)(CHCMe 2Ph)(O 2CPh3)2 (R = 2,6-i-Pr2C6H3, 2,6- Me2C6H3, 2-t-BuC 6H4, or 1 -adamantyl) are compared to newly synthesized bis(terphenylcarboxylate) species, Mo(NR)(CHCMe 2Ph)(O 2CTer)2 (Ter = 2,6-diphenyl-4- methylphenyl or 2,6-diphenyl-4-methoxyphenyl). Preparation of bis(terphenylcarboxylate) species was accomplished through protonolysis of Mo(NR)(CHCMe2R')(Me2Pyr)2 with two equivalents of TerCO2H and one of them was characterized through X-ray crystallography. Photolysis experiments of many of the biscarboxylate complexes led to rate constants for the converstion of anti to syn species, which are much slower than bisalkoxide species. Trimethylphosphine adducts of selected triphenylacetate complexes have been isolated and studied in solution. Protonolysis of Mo(NAr)(CHCMe 2R')(Me 2Pyr)2 (Ar = 2,6-i-Pr 2C6H3) with one equivalent of TerCO2H led to the isolation of a handful of monocarboxylate species, Mo(NAr)(CHCMe 2Ph)(O 2CAr')(Me2Pyr). An X-ray structure of one of them was also characterized. Several of the bis(triphenylacetate) complexes and all of the monocarboxylates are active initiators for the regioselective polymerization of diethyl dipropargylmalonate (DEPDM). In the case of the latter compounds, activity towards olefins is also observed and briefly mentioned.
Download or read book The Synthesis and Reactions of Molybdenum II and Tungsten II Alkyne Complexes written by Elaine M. Armstrong and published by . This book was released on 1989 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Characterization and Some Novel Reactions of Seven Coordinate Complexes of Molybdenum II and Tungsten II written by Christen Michael Giandomenico and published by . This book was released on 1981 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Structure and Applications of Metallacyclic Alkylidene Complexes of Molybdenum and Tungsten written by Kapil Shyam Lokare and published by . This book was released on 2009 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Molybdenum and Tungsten Enzymes written by Russ Hille and published by Royal Society of Chemistry. This book was released on 2016-10-10 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been enormous progress in our understanding of molybdenum and tungsten enzymes and relevant inorganic complexes of molybdenum and tungsten over the past twenty years. This set of three books provides a timely and comprehensive overview of the field and documents the latest research. Building on the first volume that focussed on biochemistry aspects, the second volume in the set focusses on the inorganic complexes that model the structures and reactivity of the active sites of each major group of molybdenum and tungsten enzymes. Special attention is given to synthetic strategies, reaction mechanism and chemical kinetics of these systems. The introductory chapter provides a useful overview and places the topic of the book into a wider context. This text will be a valuable reference to workers both inside and outside the field, including graduate students and young investigators interested in developing new research programs in this area.
Download or read book Synthesis Characterisation and Reactions of Neutral and Cationic Complexes of Molybdenum II and Tungsten II written by Deborah Sian Evans and published by . This book was released on 2000 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Carbene Chemistry written by Guy Bertrand and published by CRC Press. This book was released on 2002-05-14 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highlights recent discoveries in the development of rapid kinetic techniques that allow for direct visualization and state-of-the-art computational methods.
Download or read book Synthesis and Reactivity of High Oxidation State Tungsten and Molybdenum Olefin Metathesis Catalysts Bearing New Imido Ligands written by Jonathan Clayton Axtell and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1 details the synthesis of tungsten imidoalkylidene compounds bearing strongly electron-withdrawing imido ligands. An alternative synthesis involving the treatment of WCl6 with 4 equivalents of N-trimethylsilyl-substituted anilines and subsequent workup with 1,2-dimethoxyethane (DME) has been employed to form complexes of the type W(NAr)2C12(dme); syntheses employing WO2C 2(dme) as the tungsten precursor were unsuccessful. Alkylation with neopentylmagnesium chloride (ClMgNp) and subsequent treatment with trifluoromethanesulfonic acid (HOTf) affords imidoalkylidene species W(NAr)(CHCMe 3)(OTf)2(dme) (OTf = trifluoromethanesulfonate); analogous neophylidene ([W]CHCMe 2Ph) species could not be made under these conditions. Treatment of these compounds with two equivalents of LiO(2,6-(CHCPh 2)C6H3)-Et2O affords the bisaryloxide complexes of the type W(NAr)(CHCMe3)(OR)2. Ring-Opening Metathesis Polymerization (ROMP) studies using a series of these bisaryloxides show that rates of ROMP increase as the electron-withdrawing power of the substituents on the imido ligand increase if steric bulk about the metal center is held constant. A similar trend between two bisaryloxides is observed for anti-to-syn alkylidene rotation rates at 50*C in toluene-d8 . Difficulties synthesizing bis-pyrrolide complexes of the type W(NAr)(CHCMe3)(pyr)2 precluded their use as catalyst precursors; some MAP species containing the more sterically encumbering 2,5-dimethylpyrrolide ligand are presented and the metathesis activity of MAP species bearing the 2,5-dimethylpyrrolide ligand is discussed. Chapter 2 introduces Mo and W complexes bearing the current extreme in sterically bulky imido ligands, the NHIPT (HIPT = 2,6-(2,4,6-iPr 3CH2)CH3) ligand, in an effort to generate all anti alkylidene species. A non-traditional synthetic route is employed in order to install this ligand first as an anilide, and after subsequent proton transfer, as an imido ligand to form a mixed imido species of the type M(NHIPT)(N'Bu)(NH'Bu)Cl. Addition of one equivalent of 2,6-lutidinium chloride, followed by alkylation affords dialkyl species M(NHIPT)(N'Bu)Np 2, and treatment with three equivalents of pyridinium chloride yields all anti imidoalkylidene dichloride species as mono-pyridine adducts, M(NHIPT)(CHCMe 3)C 2(py) (M = Mo, W). General reactivity, including strategies for removal of the pyridine adduct as well as substitution and metathesis chemistry, are discussed. ROMP of MPCP (MPCP = 3-methyl-3-phenylcyclopropene) by a Mo-based MAP species bearing the NHIPT ligand yields predominantly cis,syndiotactic poly(MPCP) and in the homo-metathesis of 1 -octene yields ~81% cis-7-tetradecene. The possible source of trans olefinic product is addressed. Chapter 3 presents the synthesis of the first (1-adamantyl)imido species of tungsten. The functional equivalent of common bisimido precursors for other Mo/W alkylidene species, [W(NAd) 2C 2(AdNH2)1 2, is shown to be a dimer stabilized by hydrogen-bonding interactions between adamantylamine protons and adjacent chlorides bound to the second metal of the dimer. Subsequent alkylation with ClMgNp affords the expected dialkyl species, and treatment with three equivalents of 3,5-lutidinium chloride affords imidoalkylidene complex W(NAd)(CHCMe 3)(C) 2(lut)2 (lut = 3,5-dimethylpyridine). The most desirable synthetic route toward monoalkoxide pyrrolide (MAP) species proceeds through a monoaryloxide monochloride intermediate W(NAd)(CHCMe 3)(Cl)(OAr)(lut) (Ar = 2,6-(2,4,6-Me 3)C6H3, 2,6-(2,4,6-'Pr 3)C6H3). Removal of lutidine with B(C6 F5 )3 and subsequent treatment with lithium pyrrolide affords W(NAd)(CHCMe3)(pyr)(OAr) (pyr = pyrrolide); 2,5-dimethylpyrrolide analogues (W(NAd)(CHCMe3)(Me2pyr)(OAr) can be accessed via protonolysis by HOAr from W(NAd)(CHCMe3)(Me2pyr)2(lut).
Download or read book Molybdenum and Tungsten Enzymes written by Russ Hille and published by Royal Society of Chemistry. This book was released on 2016-09-30 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been enormous progress in our understanding of molybdenum and tungsten enzymes and relevant inorganic complexes of molybdenum and tungsten over the past twenty years. This set of three books provides a timely and comprehensive overview of the field and documents the latest research. Building on the first and second volumes that focussed on biochemistry and bioinorganic chemistry aspects, the third volume focusses on spectroscopic and computational methods that have been applied to both enzymes and model compounds. A particular emphasis is placed on how these important studies have been used to reveal critical components of enzyme mechanisms.This text will be a valuable reference to workers both inside and outside the field, including graduate students and young investigators interested in developing new research programs in this area.
Download or read book Innovative Applications of Mo W Based Catalysts in the Petroleum and Chemical Industry Emerging Research and Opportunities written by Ge, Hui and published by IGI Global. This book was released on 2017-02-08 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mo(W)-Based Catalysts have the capacity to drastically impact many different industries. Research on their most current applications is important for the success of many organizations and companies, specifically the chemical and petroleum industries. Innovative Applications of Mo(W)-Based Catalysts in the Petroleum and Chemical Industry: Emerging Research and Opportunities is an informative resource that overviews emerging methods and techniques that incorporate 2D layer Mo(W) dichalcogenides. Featuring extensive coverage on a range of subjects including 2D nanosheets, hybridization, dichacogenides, and oxide based catalysts, this is an ideal publication for academicians, students, engineers, and researchers seeking insight on the latest advancements in Mo(W)-Based catalyst applications.
