Download or read book Synthesis and Characterization of Transitional Metal Pyridine Containing Complexes with Both Catalytic and Therapeutic Applications written by Magy Amir Maurice Mekhail and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pyridinophanes derived from pyclen are the focus of many studies as biological mimics, chelators, and catalytic precursors. Therefore, the desire to tune the reactivity of metal pyridinophane complexes has inspired modifications that include expansion of ring size and substitutions to the N-atoms. However, substitution on the pyridine moiety is largely unexplored to date. Herein, new synthetic strategies for pyclen-congeners bearing electron donating and electron withdrawing groups are introduced, resulting in doubling the number of pyridine functionalized molecules in literature. Further, the influence of such modifications on properties and reactivity of two metals (Fe(III) and Cu(II)) is described. For the Fe(III) system, 4-substitution of the pyridine ring successfully provides a regulatory handle on the electronic properties and the catalytic C-C coupling activity of the respective Fe complexes. These are the first examples of a structure-activity relationship study with the impact of electronic properties decoupled from structural properties and investigated. The Fe(III) system was also explored in a catalase mimetic study to determine the role of ligand design on the activity of the metal center through changing electronic properties and rigidity of the ligand. Varying the electronic properties of the ligand has a minor effect on catalase activity, but changes to the geometry of the complex have significant impacts on the system. This activity was also successfully observed to cellular models. The Cu(II) system was investigated as a superoxide dismutase mimic. Cu(II) Pyclen complexes, specifically, has been shown to match its coordination environment and to have high binding affinity. My studies highlight that modifications to the pyridine ring of the ligand can tune the redox potential, while exhibiting high binding stabilities and retaining the coordination environment. In fact, one of the complexes studied exhibits one of the highest SOD activities reported to date, which is hypothesized to be the result of not only the electronic properties of the Cu center but also the high binding stability exhibited by this complex. Altogether, this work focused on functionalizing the pyridine ring in pyridinophanes and studying the effect of the modifications on the electronics of metal complexes and their reactivity with both catalytic and potential therapeutic application.

Download or read book Synthesis Characterization and Applications of Pyridine and Pyridol based Azamacrocyclic Transition Metal Complexes written by Hannah May Johnston and published by . This book was released on 2018 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis Characterization and Theranostic Applications of Pyridine Containing Macrocyclic Ligands and Their Divalent Transition Metal Complexes written by Kristof Pota and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pyridine written by Pratima Parashar Pandey and published by BoD – Books on Demand. This book was released on 2018-07-18 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is designed and styled in order to give researchers a vast horizon about pyridine. A deep look in the structural analysis of pyridine provides a base for all the building blocks derived from it and its applications. Pyridines and pyridine moieties are found in many natural products, such as vitamins, coenzymes, alkaloids, many drugs, and pesticides. The book is divided into three parts: the first takes to the introduction, the second part deals with composition of various compounds using heterocyclic ring of pyridine, and the third part discusses about applications of pyridine compounds.

Download or read book Rational Design Synthesis and Characterization of Amide Functionalized Pyridine and Benzimidazole Transition Metal Complexes written by Samuel S. K. Asem and published by . This book was released on 2011 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study expands our efforts to make a new class of Pt (II) compounds analogous to cisplatin and its derivatives using sterically hindered ligands. Pt compounds in this series have been synthesized using specially designed pyridine and benzimidazole ligands. These heterocycles, amide functionalized at position 2 with aryl and alkyl pendants, rapidly change their mode of coordination depending on the pH of the medium. These ligands, synthesized using condensation chemistry, also coordinate to Co(II), Ni(H), Cu(lI), and Zn(1I) generally as anionic bis-chelates through the benzimidazole nitrogen and the carbonyl oxygen, creating a four-coordinate complex with the exception of an unusual trigonal bipyramidal Zn(H) complex. I H NMR temperature studies reveal that these ligands interconvert between imide and amide isomers and that electron withdrawing pendants favor amide isomers. Crystal structures of Co(II) and Ni(1I) complexes of N-( I-methylbenzimidazol-2-yl)cyclohexanecarboxamide, for example, show two ligands bind per metal ion when reacted with acetate and nitrate salts. The bischelates of these Ni(1I) complexes also show expansions of their coordination spheres from four to five-coordinate. Furthermore, these Ni(II) bis-chelated complexes possess square planar or distorted 4-coordinate geometries. The synthesis and properties of several new Pt (II) complexes containing these ligands will be presented. A second generation and novel complex class containing metal-binding, linker and recognition domains is reported. Both classes of Pt complexes were obtained using a synthetic methodology which favors the cis isomers. The second generation complex crystallizes in the monoclinic space group P2dn with lattice dimensions a = 17.7393(5) A, b = 11.4632(3) A, c = 19.3959(5) A and ~ = 99.794(3)°. These complexes have been characterized using physical methods that include X-ray crystallography, IH &13C NMR, Mass spectrometry, UV and IR spectroscopies. Complexes similar in structure to cisplatin and carboplatin show varying cytotoxic properties toward different cancer cell lines. Additionally, some of these new Pt complexes show comparable and promising cytotoxicity against prostate cancer cell lines.

Download or read book Synthesis and Characterization of Transition Metal Complexes of 2 2 pyridyl benzimidazole and 2 6 bis benzimidazolyl pyridine written by Frank L. Messana and published by . This book was released on 1999 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Early Transition Metal Complexes of Pyridine Derivatives written by Eugene Chong and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis Characterization and Reactivity of Transition Metal Complexes Supported by Heteropolydentate Ligation written by Adam Ruddy and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization and Catalytic Application of Unsaturated Transition Metal Complexes written by Todd J. Johnson and published by . This book was released on 1992 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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/CN 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 CH bond of bridging methylene group, was found to react with PhINTs to result in the formation of a new CN bond and cleavage of one existing NC(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 CH insertion of a Ru(IV)-imido/nitrene intermediate and was found to undergo the observed CN bond cleavage. Such type of CN 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 Exploring Chemistry with Pyridine Derivatives written by Satyanarayan Pal and published by BoD – Books on Demand. This book was released on 2023-01-04 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses the chemistry and applications of pyridine derivatives. The library of pyridine derivatives is growing steadily with numerous synthetic analogues already described and the identification of new, naturally occurring pyridine-based compounds. The book includes ten chapters organized into two parts. The first part focuses on the numerous types of reactions that arise from pyridine derivatives. The second part examines the pharmaceutical applications of pyridine derivatives as well as their usefulness as sensors for metal cations and extracting agents for platinum group metals.

Download or read book Recent Developments in the Synthesis and Applications of Pyridines written by Parvesh Singh and published by Elsevier. This book was released on 2022-09-15 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent Developments in the Synthesis and Applications of Pyridines is a comprehensive handbook for organic chemists working on innovative approaches to the synthesis of pyridines. Written by scientists in both academia and industry and designed to be a standalone reference, the book features reviews, research results and case studies on synthetic methods and applications of pyridine-based chemotypes. The book will bridge the gap between industry and academia by presenting recent innovative approaches to the synthesis of pyridines, diverse application of pyridines in drug development, heterogeneous catalysis and material science, as well as benchtop to shelf narratives of pyridine-based compounds in the industry. The role of computational chemistry in the development of pyridine-based bioactive molecules is also included. This reference is essential for researchers in organic chemistry both in academic and industrial settings, postgraduates in chemistry and medicinal chemistry. Includes a detailed review of recent research on the reactivity, synthesis and applications of pyridines Features concise accounts of the reactivity, synthetic and optimized protocols Discusses the medicinal, inorganic and polymer chemistry applications of pyridines

Download or read book Synthesis and characterization of solvent ligated transition metal complexes containing weakly coordinating anions and their catalytic reactivity written by Yanmei Zhang and published by . This book was released on 2004 with total page 174 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 Iron Catalysis in Organic Chemistry written by Bernd Plietker and published by John Wiley & Sons. This book was released on 2008-09-08 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first comprehensive book to cover this exciting field also deals with the biological aspects, such as enzymes with iron. Following an introduction, this handy reference and handbook goes on to deal with reductions, oxidations of C, H- and C=C bonds, oxidative allylic oxygenation and amination, the oxidation of heteroatoms, cross coupling reactions, aromatic and nucleophilic substitutions, addition to carbonyl compounds, and cyclisations as well as ring opening reactions. The chapters are clearly classified according to the reaction type, allowing readers to quickly locate the desired information.

Download or read book synthesis and characterization of some transition metal hydrazones pyridine complexes and their catalytic activity written by reham ibrahim aibrahim and published by . This book was released on 2003 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Redox noninnocent Pyrazine diimine Iron Complexes and an Inverted Pyridine diimine Ligand written by Jaylan Billups and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cooperativity between the metal center and the ligand has been shown in nature to be an important feature of systems that catalyze two-electron processes that first-row transition metals usually cannot catalyze on their own. In these cases, the ligand acts as a site of reactivity that in many instances can store electrons or react directly with substrates in solution. The design and study of systems where there is synergy between the metal and the ligand have been leveraged to catalyze polymerization and hydrogenation-type reactions as well as the activation of small molecules such as dihydrogen. Specifically, the pyridine(diimine) ligand scaffold has been reported to store up to three electrons on the ligand backbone that can later be used in catalysis. Wanting to expand on this work, we have designed and synthesized a new pincer that has redox-noninnocent properties similar to pyridine(diimine) ligands but incorporates a pyrazine ring instead of a pyridine ring to give rise to new electronic properties. Pyrazine(diimines) also have an uncoordinated 4-position nitrogen that can be further functionalized to fine-tune the electronic properties of the ligand. In Chapter II we will discuss bisligated iron(II) pyrazine(diimine) (PZDI) complexes in three different oxidation states where we used spectroscopic and computational techniques as well as comparison to known pyridine(diimine) iron(II) complexes to support our assignments of ligand-based reduction. Chapter III will focus on monoligated pyrazine(diimine) iron(II) complexes as compared to analogous pyrazine(diimine) systems where the central metal is manganese, cobalt, or nickel, as well as compare our pyrazine(diimine) iron(II) complexes to reported pyridine(diimine) iron(II) analogs. We have also synthesized a new inverted pyridine(diimine) ligand scaffold that has an NCN binding pocket, which will be discussed in Chapter IV. In the design of the inverted pyridine(diimine) ligand we have left in place the 4-position nitrogen from our previously described pyrazine(diimine) ligand, maintaining a Lewis basic site for functionalization. Overall, we hope to describe the results we observed with both monoligated and bisligated iron(II) pyrazine(diimine) complexes as well as discuss our approach to the design of and progress towards a new inverted pyridine(diimine) ligand scaffold.