Download or read book Studies on Molybdenum Iron and Ruthenium Complexes with Tetradentate Ligands as Oxidation Catalysts written by Christopher John Whiteoak and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Iron and Molybdenum Complexes Supported by Pincer Ligands written by Steven Ryan Ruark and published by . This book was released on 2016 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since its discovery in the mid 1950’s, olefin metathesis has become one of the most widely used chemical reactions. Olefin metathesis involves the breaking of carbon-carbon double bonds and the redistribution of the fragments to form new olefins by way of a metal alkylidene.6 It is used in industry to convert cheap plant oils into useful products such as alpha olefins, jet fuel and green diesel. The Elevance BioRefinery has the capacity to run this reaction and produce up to 400 million pounds of products per year. The most expensive part in this refinery process is the catalyst itself. The catalyst currently used is an alkylidene complex of ruthenium—an expensive and rare metal. This has led the Schrodi group to explore the possibility of developing catalysts based on abundant and cheap metals such as iron or molybdenum.40,41 We first attempted to support iron with a tridentate pincer ligand, OiPrPONOP, however the ligand was not robust enough and more than one ligand was required to adequately protect the iron xv center. Ultimately, the ligand was reacted with Fe(PMe3)4 to make (OiPrPONOP)Fe(PMe3)2. This complex is very stable and unreactive, preventing its transformation into any catalytic species. We then turned our attention to a pincer OCO-NHC ligand. This ligand was able to stabilize an iron tricyclohexyphosphine complex, (OC-NHC)FePCy3, However, attempts to react this complex with diazo compounds to form an iron alkylidene (OCO-NHC)Fe=CHR were unsuccessful. Further studies focused on replacing the PCy3 ligand with pyridines, in an attempt to make the complex more labile. However, the resulting species proved much too sensitive to water and was difficult to isolate and characterize. Inspired by the research done by the Chirik group where they reduced several arylpyridinediimine ( ArPDI) ironII complexes into a reduced N2-bridged complex. They reported the bound N2 molecules would readily exchange with 15N2 and ultimately they were able to form an iron alkylidene complex. However, the complex was not metathesis active.54,42 We successfully reduced MesPDIFeBr2 into the bis-N2 complex but the complex refused to react cleanly in attempts to make iron alkylidene species. We also explored the possibility of forming a molybdenum alkylidene supported by a tridentate iPrPONOP ligand. After successfully forming iPrPONOPMoCl3 we tried several strategies to form and isolate a molybdenum alkylidene. We attempted a similar reduction as the iron species trying to access a bis-N2 bridged molybdenum complex but the reaction resulted in decomposition of the complex. We then attempted ‘Schrock type’ chemistry by reacting the iPrPONOPMoCl3 complex with Grignard reagents.81 However, this strategy resulted in decomposition as well. We successfully performed ring opening metathesis polymerization (ROMP) of norbornene by adding Grignard reagents to several different tridentate supported MoCl3 precatalysts. Select polymers were then analyzed for cis content by 1 H NMR to probe for serioregularity. The only precatalyst to have more than 50% cis content was the BinapthPONOPMoCl3 / methyl- and trimetylsilylmethlyl-Grignard reagents but only when run at 25 °C. xvi We were able to perform ROMP of dicyclopentadiene (DCPD) with the molybdenum complex / Grignard reagents. However, while the fully polymerized product is extremely hard and transparent we could only achieve a soft nontransparent product, indicating incomplete polymerization.
Download or read book Ruthenium Oxidation Complexes written by William P. Griffith and published by Springer Science & Business Media. This book was released on 2010-11-03 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ruthenium Oxidation Complexes explores ruthenium complexes, particularly those in higher oxidation states, which function as useful and selective organic oxidation catalysts. Particular emphasis is placed on those systems which are of industrial significance. The preparation, properties and applications of the ruthenium complexes are described, followed by a presentation of their oxidative properties and summary of the different mechanisms involved in the organic oxidations (e.g. oxidations of alcohols, alkenes, arenes and alkynes, alkanes, amines, ethers, phopshines and miscellaneous substrates). Moreover, future trends and developments in the area are discussed. This monograph is aimed at inorganic, organic, industrial and catalysis chemists, especially those who wish to carry out specific organic oxidations using catalytic methods.
Download or read book Chiral Iron Pyridine Complexes and Ruthenium Complexes with N Heterocyclic Carbene and Macrocyclic N O Donor Atom Ligands written by Kar-Yee Lam and published by . This book was released on 2017-01-26 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Chiral Iron Pyridine Complexes and Ruthenium Complexes With N-heterocyclic Carbene and Macrocyclic (N, O) Donor Atom Ligands: Synthesis, Catalytic Activity and Biological Studies" by Kar-yee, Lam, 林嘉儀, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled CHIRAL IRON PYRIDINE COMPLEXES AND RUTHENIUM COMPLEXES WITH N-HETEROCYCLIC CARBENE AND MACROCYCLIC(N, O) DONOR ATOM LIGANDS: SYNTHESIS, CATALYTIC ACTIVITY AND BIOLOGICAL STUDIES Submitted by Lam Kar Yee For the degree of Doctor of Philosophy at The University of Hong Kong in April 2016 Transition metal complexes are widely applied as catalysts for organic transformation reactions such as the oxygen atom and nitrene transfer reactions and there is a growing interest to develop the medicinal applications of transition metal complexes. The studies of reactive metal-oxo and metal-nitrene intermediates are important in probing the underlying reaction mechanisms. This thesis is comprised of three main parts. In the first part, iron complexes with chiral pyridine ligands, such as 4′,6-disubstituted 2,2′ 6′,2″-terpyridine (NNN ) and 4′,6,6″-trisubstituted 2,2′ 6′,2″''-terpyridine (NNN ), were studied for their catalytic activities in asymmetric epoxidation, aziridination, amidation and sulfimidation reactions. The Fe-NNN complex catalyzed intermolecular nitrene transfer/CN bond formation reactions of styrenes with PhINTs in moderate product yields. For the asymmetric intramolecular amidation, the Fe-NNN complex can catalyze intramolecular C-N bond formation using PhI(OAc) as oxidant to form five- or six-membered ring products. The highest product yield obtained was 91 %. The complete conversion of para-substituted phenyl methyl sulfides to corresponding sulfimides was observed by using the Fe-NNN 1 2 complex as catalyst. Both the Fe-NNN and Fe-NNN complexes catalyzed asymmetric epoxidation of styrene using PhIO as oxidant at 0 C. The reaction intermediates of the nitrene/oxygen transfer reactions were studied by ESI-MS and high-valent iron-ligand multiple bonded species are proposed to be the reaction intermediates. In the second part, ruthenium pincer N-heterocyclic carbene (CNC) complexes were prepared and characterized by spectroscopic means and X-ray crystallography. II 2+ Complex [Ru (CNC)(bpy)(MeCN)], in which the CNC ligand adopts a fac-coordination mode and contains reactive CH bond of bridging methylene group, was found to react with PhINTs to result in the formation of a new CN bond and cleavage of one existing NC(methylene) bond of the CNC ligand, as revealed by X-ray crystal structure determination of the ruthenium complex product. The reaction 2+ of [Ru(CNC)(bpy)(MeCN)] with PhINTs was monitored by ESI-MS, UV-vis, and NMR spectroscopy; a paramagnetic Ru(III)-amido complex was isolated, which apparently resulted from intramolecular imido/nitrene CH insertion of a Ru(IV)-imido/nitrene intermediate and was found to undergo the observed CN bond cleavage. Such type of CN bond cleavage induced by metal-mediated imido/nitrene insertion is unprecedented in literature. The final part of this thesis is the study of the anti-angiogenic and anti-metastatic properties of the ruthenium complexes. Ruthenium complexes with different oxidation states (+2 and +3) and ligands (pincer NHC and macrocyclic (N, O) donor atom ligands) were examined for their cytotoxicity and anti-angiogenesis activity. III Among the complexes studied, [Ru (N O )Cl ]Cl (Ru-1) displays promising 2 2 2 inhibi
Download or read book Iron and Ruthenium Complexes with Nitrogen and Oxygen Donor Ligands for Anti Cancer and Anti Viral Studies written by LAI-MING ELLA. WONG and published by . This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Iron and Ruthenium Complexes With Nitrogen and Oxygen Donor Ligands for Anti-cancer and Anti-viral Studies" by Lai-Ming, Ella, Wong, 黃禮明, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled IRON AND RUTHENIUM COMPLEXES WITH NITROGEN AND OXYGEN DONOR LIGANDS FOR ANTI-CANCER AND ANTI-VIRAL STUDIES Submitted by Ella Lai-Ming Wong For the degree of Doctor of Philosophy at The University of Hong Kong in February 2006 Development of drug resistance in cancer chemotherapy has stimulated the search for new anti-cancer drugs. Due to the versatile oxidation states and diverse coordination chemistry, iron and ruthenium compounds are potential candidates for new anti-cancer agents and metallopharmaceuticals. In this study, iron(II) complexes containing polypyridines as auxiliary ligand and ruthenium-oxo oxalato cluster were synthesized and characterized by X-ray crystallography, and their anti-cancer and anti-viral properties were examined. The iron(II) complexes, [Fe(R-qpy)(CH CN) ](ClO ) [qpy = 3 2 4 2 2,2′ 6′,2″ 6″,2′″ 6′″,2″″-quinquepyridine, R = H (1a) and Ph (1b)] and [Fe(Py -OH)(CH CN)](ClO ) (2) [Py-OH = 5 3 4 2 5 2,6-bis[hydroxybis(2-pyridyl)methyl]pyridine] were stable in physiological buffers and exhibited significant cytotoxicities against some established human cancer cell lines. According to the MTT assay, their IC values were 0.1 - 70 50 M; they exhibited more pronounced cytotoxicities against hepatocellular carcinoma cells than against other type of cancer cells. Flow cytometry studies revealed that 1a could cause cell cycle arrest of HeLa cells at the S-phase, which involved DNA synthesis. Complex 1a was found to catalyze epoxidation, aziridination and amidation of hydrocarbons with good substrate conversions and high product yields. The iron(IV)-oxo and -imido reactive intermediates were generated in situ and their formulations were verified by mass spectroscopy. By Evan''s method, the result supported the iron(IV) formulation with a low-spin d electronic configuration (S = 1). A ruthenium-oxo oxalato cluster formulated as Na [Ru ( -O) (C O ) ] (3) 7 4 3 4 2 4 6 was prepared. Structural studies and magnetic measurements revealed that the ruthenium atoms adopted the oxidation states of +III, +III, +III and +IV. Complex 3 showed anti-HIV properties on infected cells. Using the HIV-1(BaL) virus infected Hut/CCR5 cells, 3 was found to exhibit >90% inhibition on viral replication at 5 M concentration. Similar findings were obtained with other HIV-infected cell lines including GHOST/CXCR4 and PBMCs. Complex 3 was non-cytotoxic to these cells even at 50 M concentration. Relevant to anti-HIV activity, 3 was found to inhibit HIV-1 reverse transcriptase activity in vitro with IC = 2 nM. 50 III A series of ruthenium complexes, cis-[Ru (Me -tet)Cl ]ClO [Me -tet = 6 2 4 6 N, N, N′, N′-tetramethyl-3,6-dimethyl-3,6-diazaoctane-1,8-diamine], III III trans-[Ru (pyz) Cl]Cl (pyz = pyrazole), trans-[Ru (3Mepyz) Cl ]Cl 4 2 4 2 II III [3Mepyz = 3-methylpyrazole], [Ru (3Mepyz) ]Cl, [Ru (salen)(H O) ]Y 6 2 2 2 [H-salen = N, N''-bis(salicylidene)ethylenediamine, Y = Cl and PF ], 2 6 III cis-[Ru (cyclen)Cl]Cl [cyclen = 1,4,7,10-tetraazacyclododecane], 2III trans-[Ru (BiIml) Cl]Y [BiIml = biimidazole, Y = Cl and PF], and 2 2 6 II cis-[Ru (BiIml) (DMSO) ](ClO ) were examined for anti-cancer activities. 2 2 4 2 Their IC values were 4 - 100 M and their cytotoxicities could be affected by 50 the auxiliary ligands. The reduction potentials of the ruthenium compounds were +/0 in
Download or read book Industrial Applications of Homogeneous Catalysis written by A. Mortreux and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: Catalysts are now widely used in both laboratory and industrial-scale chemistry. Indeed, it is hard to find any complex synthesis or industrial process that does not, at some stage, utilize a catalytic reaction. The development of homogeneous transition metal catalysts on the laboratory scale has demonstrated that these systems can be far superior to the equivalent heterogeneous systems, at least in terms of selectivity. is an increasing interest in this field of research from both an Thus, there academic and industrial point of view. In connection with the rapid developments in this area, four universities from the E.E.C (Aachen, FRG; Liege, Belgium; Milan, Italy; and Lille, France) have collaborated to organise a series of seminars for high-level students and researchers. These meetings have been sponsored by the Commission of the E.E.C and state organizations. The most recent of these meetings was held in Lille in September 1985 and this book contains updated and expanded presentations of most of the lectures given there. These lectures are concerned with the field of homogeneous transition metal catalysis and its application to the synthesis of organic intermediates and fine chemicals from an academic and industrial viewpoint. The continuing petroleum crisis which began in the early 1970s has given rise to the need to develop new feedstocks for the chemical industry.
Download or read book Cationic Ruthenium Complexes in Catalysis written by Stark. Matthew J. (Matthew James) and published by . This book was released on 2018 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: With increasing complexity of metal complexes, it is of worthwhile interest to pursue systematic examinations of ligand modifications to study their impact on the reactivity of a catalyst. To that end, this study aimed to understand the effect electron-withdrawing ligands conveyed to catalytic activity in the etherification of propargylic alcohols and related reactions. A number of half-sandwich ruthenium complexes bearing ligands with varying electron–withdrawing properties were synthesized and structurally characterized. Their electronic and structural properties were investigated utilizing X-ray crystallography, revealing that the series of complexes did not vary significantly in structure. The complexes were studied electronically with cyclic voltammetry, which discovered that the coordinated electron-withdrawing ligands resulted in complexes that were more difficult to oxidize and with possibly decreased electron density at the ruthenium center. All complexes showed catalytic activity in the etherification of propargylic alcohols and in the formation of oxygen-containing heterocycles from propargylic alcohols and diketones. Thermal instability offers an explanation as to why some catalyst systems do not perform very well at elevated temperatures. In a separate study, a more stable tridentate ligand was employed as an architecture for further study in this electronic fine-tuning methodology. A new ruthenium complex bearing a tridendate diacetylpyridine ligand was synthesized, characterized, and employed as catalyst in the coupling of carboxylic acids to terminal alkynes to form enol esters with good regioselectivity. Iron offers a number of advantages in transition metal catalysis, as it is inexpensive and relatively non-toxic. Based on preliminary findings from the Bauer laboratory, an in situ catalyst formed through oxidation of ferrocene boronic acid was found to be catalytically active in the etherification of propargylic acetates. Most interestingly, and opposed to all catalytic reactions performed for this study, the ferrocenium cation does not require elevated temperatures and performs well at room temperature.
Download or read book Inorganic and Organometallic Transition Metal Complexes with Biological Molecules and Living Cells written by Kenneth Kam-Wing Lo and published by Academic Press. This book was released on 2016-12-30 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inorganic and Organometallic Transition Metal Complexes with Biological Molecules and Living Cells provides a complete overview of this important research area that is perfect for both newcomers and expert researchers in the field. Through concise chapters written and edited by esteemed experts, this book brings together a comprehensive treatment of the area previously only available through scattered, lengthy review articles in the literature. Advanced topics of research are covered, with particular focus on recent advances in the biological applications of transition metal complexes, including inorganic medicine, enzyme inhibitors, antiparasital agents, and biological imaging reagents. Geared toward researchers and students who seek an introductory overview of the field, as well as researchers working in advanced areas Focuses on the interactions of inorganic and organometallic transition metal complexes with biological molecules and live cells Foscuses on the fundamentals and their potential therapeutic and diagnostic applications Covers recent biological applications of transition metal complexes, such as anticancer drugs, enzyme inhibitors, bioconjugation agents, chemical biology tools, and bioimaging reagents
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1999 with total page 848 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Characterization and Catalytic Studies of Molybdenum Thiolate Complexes and Copper Complexes with Substituted NS2 macrocyclic Ligands written by Antony Alex Tipton and published by . This book was released on 1999 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Organometallic Chemistry written by and published by Academic Press. This book was released on 1992-11-18 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Organometallic Chemistry
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:
Download or read book Hydrogen Transfer Reactions written by Gabriela Guillena and published by Springer. This book was released on 2016-09-27 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Current Chemistry Collections presents critical reviews from the journal Topics in Current Chemistry organized in topical volumes. The scope of coverage is all areas of chemical science including the interfaces with related disciplines such as biology, medicine and materials science. The goal of each thematic volume is to give the non-specialist reader, whether in academia or industry, a comprehensive insight into an area where new research is emerging which is of interest to a larger scientific audience. Each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years are presented using selected examples to illustrate the principles discussed. The coverage is not intended to be an exhaustive summary of the field or include large quantities of data, but should rather be conceptual, concentrating on the methodological thinking that will allow the non-specialist reader to understand the information presented. Contributions also offer an outlook on potential future developments in the field.
Download or read book Iron and Ruthenium Complexes with Nitrogen and Oxygen Donor Ligands for Anti cancer and Anti viral Studies written by Lai-Ming Wong (Ella) and published by . This book was released on 2006 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Twin Polymerization written by Stefan Spange and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-11-05 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Twin polymerization is a novel approach where two distinct polymers are produced from a single source monomer, thus being an excellent tool for the synthesis of hybrid materials. The author introduces the principles of various twin polymerization processes, their classification and practical use. The book is supplied with numerous individual examples, demonstrating the potential of this strategy in materials synthesis.
Download or read book Non Noble Metal Catalysis written by Robertus J. M. Klein Gebbink and published by John Wiley & Sons. This book was released on 2019-04-29 with total page 610 pages. Available in PDF, EPUB and Kindle. Book excerpt: An expert overview of current research, applications, and economic and environmental advantages The study and development of new homogeneous catalysts based on first-row metals (Mn, Fe, Co, Ni, and Cu) has grown significantly due to the economic and environmental advantages that non-noble metals present. Base metals offer reduced cost, greater supply, and lower toxicity levels than noble metals?enabling greater opportunity for scientific investigation and increased development of practical applications. Non-Noble Metal Catalysis provides an authoritative survey of the field, from fundamental concepts and computational methods to industrial applications and reaction classes. Recognized experts in organometallic chemistry and homogeneous catalysis, the authors present a comprehensive overview of the conceptual and practical aspects of non-noble metal catalysts. Examination of topics including non-innocent ligands, proton-coupled electron transfer, and multi-nuclear complexes provide essential background information, while areas such as kinetic lability and lifetimes of intermediates reflect current research and shifting trends in the field. This timely book demonstrates the efficacy of base metal catalysts in the pharmaceutical, fine-chemical, and agrochemical industries, addressing both environmental and economic concerns. Providing essential conceptual and practical exploration, this valuable resource: -Illustrates how unravelling new reactivity patterns can lead to new catalysts and new applications -Highlights the multiple advantages of using non-noble metals in homogenous catalysis -Demonstrates how the availability of non-noble metal catalysis reduces costs and leads to immense savings for the chemical industry -Reveals how non-noble metal catalysis are more sustainable than noble metals such as palladium or platinum Non-Noble Metal Catalysis: Molecular Approaches and Reactions is an indispensable source of up-to-date information for catalytic chemists, organic chemists, industrial chemists, organometallic chemists, and those seeking to broaden their knowledge of catalytic chemistry.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2001 with total page 832 pages. Available in PDF, EPUB and Kindle. Book excerpt:
