Download or read book Biomimetic Carboxylate bridged Diiron Complexes written by Mikael Antoine Minier and published by . This book was released on 2015 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1: Understanding the Utility of Hydrogen Bonding Donors in the Secondary Coordination Sphere of Non-heme Metal Complexes Chapter 1 is a mini-review that covers systematic studies on the effect of hydrogen bonding donors on the properties of metal complexes. Generalizing across different metals studied in biomimetic chemistry, the review allows for the comparison between different systems and generalizations are drawn about the effects of secondary coordination sphere hydrogen bond donors. Chapter 2: 19F NMR Study of Ligand Dynamics in Carboxylate-Bridged Diiron(II) Complexes Supported by a Macrocyclic Ligand A series of asymmetrically carboxylate-bridged diiron(II) complexes featuring fluorine atoms as NMR spectroscopic probes, [chemical formula ...] (10), [chemical formula ...] (11), and [chemical formula ...] (12) were prepared and characterized by X-ray crystallography, M6ssbauer spectroscopy, and VT 19F NMR spectroscopy. These complexes are part of a rare family of syn-N diiron(II) complexes, [chemical formula ...], that are structurally very similar to the active site of MMOHred. Solution characterization of these complexes demonstrates that they undergo intramolecular carboxylate rearrangements, or carboxylate shifts, a dynamic feature relevant to the reactivity of the diiron centers in bacterial multicomponent monooxygenases. Chapter 3: Structural Characterization of Carboxylate-Bridged and Hydroxo-Bridged Dizinc(II) Complexes Supported by a Macrocyclic Ligand Using a syn-N dinucleating macrocyclic ligand, H2PIM, a doubly carboxylate-bridged dizinc(II) complex, [chemical formula ...] (6) was prepared. In crystallizations of 6, two pseudoisomorphs of [chemical formula ...] (7) were discovered. On route to the synthesis of 6, a zinc complex, [chemical formula ...] (4) was prepared and the product upon reaction with air, [chemical formula ...] (5), was crystallized. Chapter 4: Secondary Coordination Sphere Modulation of Redox Potentials in Azide-Bridged Diiron(II) Complexes Observation that the H2PIM macrocyclic ligand provides an extra binding site for the binding of small molecules adjacent to corresponding diiron(II) complexes inspired the appendage of a secondary coordination sphere hydroxyl group to the ligand. The new ligand, H3PIM2, models not only the primary coordination sphere of the diiron sites of methane monooxygenase and toluene/o-xylene monooxygenase, but also that of a local threonine in the secondary coordination sphere. This chapter explores the differences between the PIM system and PIM2 system through the electrochemistry of the azido diiron(II) derviatives. Chapter 5: Synthesis and Characterization of a Linear Dinitrosyl-Triiron Complex Nitric oxide is released during the immune response by the host during bacterial infection. To counteract this response, bacteria have evolved nitric oxide reductases to convert NO to N2O. Some of these nitric oxide reductases contain a flavodiiron active site that have bridging carboxylates and hydroxides. Only a handful of synthetic complexes currently exist as models for the protein reactivity. Here we report the reaction of [chemical formula ...] (4) with NO(g) and Ph3CSNO to prepare the dinitrosyl-triiron complex [chemical formula ...] (5). The reaction was monitored by U V-Vis and ReactIR spectroscopy and compound 5 was characterized by X-ray crystallography, 5 7Fe M6ssbauer spectroscopy, Evans' method, and FTIR spectroscopy. The IR spectrum of compound 5 compares favorably to experimental spectroscopic data obtained for the proposed mononitrosylated intermediate of the protein. Chapter 6: Doubly and Triply Carboxylate Bridged Bis(ethylzinc) Complexes and Formation of the ([mu]-Oxo)tetrazinc Carboxylate [chemical formula ...] Ethylzinc 2,6-bis(p-tolyl)benzoate converts between two forms in solution. Through NMR spectroscopic techniques and X-ray crystallography, the species in equilibrium were identified as [chemical formula ...] (1), [chemical formula ...] (2), and diethyl zinc [chemical formula ...]. The equilibrium provides a model for understanding the speciation between doubly and triply m-terphenylcarboxylate-bridged diiron(II) and mononuclear iron(II) complexes. Evidence is presented for the occurrence of coordinatively unsaturated trigonal zinc species in solution. Both 1 and 2 decompose in air to form the T-symmetric oxozinc carboxylate, [chemical formula ...] (3). Appendix A: Synthesis and Characterization of Mononuclear, Pseudotetrahedral Cobalt(III) Compounds The preparation and characterization of two mononuclear cobalt(III) tropocoronand complexes, [chemical formula ...] and [chemical formula ...], are reported. The cobalt(III) centers exist in rare pseudotetrahedral conformations, with twist angles of 65° and 74° for the [Co(TC-5,5]+ and [Co(TC-6,6)]+ species, respectively. Structural and electrochemical characteristics are compared with those of newly synthesized [chemical formula ...] and [chemical formula ...] analogs. The spin state of the pseudotetrahedral [chemical formula ...] was determined to be S = 2, a change in spin state from the value of S = 1 that occurs in the square-planar and distorted square-planar complexes, [chemical formula ...] and [chemical formula ...], respectively. Appendix B: Synthetic Strategies toward Sterically Demanding Macrocyclic Ligands In order to prevent the formation of iron complexes of nuclearity higher than 2, a picket-fence macrocyclic ligand, H2tipp4PIM was designed. This chapter discusses the progress towards the synthesis of this ligand as well as design strategies.

Download or read book Advances in Non heme Diiron Modeling Chemistry written by Loi Hung Do and published by . This book was released on 2011 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chapter 1 A comprehensive review of diiron modeling in the Lippard group over the past thirty years is presented. This account describes the different strategies employed to prepare biomimetic complexes of non-heme diiron protein active sites, highlighting the accomplishments of the past as well as the challenges for the future. Studies of various model systems have led to a more profound understanding of the fundamental properties of carboxylate-bridged diiron units and their reactivity toward molecular oxygen and organic substrates. The key principles and lessons that have emerged from these studies have been an inspiration for the original work presented in this thesis. Chapter 2 A series of phenoxylpyridyl and phenoxylimine ligands, H2LR,R' (compounds derived from bis(phenoxylpyridyl)diethynylbenzene, where R = H, Me, or t-Bu, and R' = H, or Ph) and H2BIPSMe,Ph (bis((phenylphenoxyl)iminephenyl)sulfone) were synthesized as platforms for non-heme diiron(II) protein (III) core and molecular oxygen as the source of the bridging oxo group. The [LMe,Ph]2- ligand is robust toward oxidative decomposition and does not display any reversible redox activity. Chapter 3 A dinucleating macrocycle, H2PIM, containing phenoxylimine metal-binding units has been prepared. Reaction of H2PIM with [Fe2(Mes)4] (Mes = 2,4,6-trimethylphenyl) and sterically hindered carboxylic acids, Ph3CCO2H or ArTolCO2H (2,6-bis(p-tolyl)benzoic acid), afforded complexes [Fe2(PIM)(Ph3CCO2)2] (1) and [Fe2(PIM)(ArTolCO2)2] (2), respectively. X-ray diffraction studies revealed that these diiron(II) complexes closely mimic the active site structures of the hydroxylase components of bacterial multi-component monooxygenases (BMMs), particularly the syn disposition of the nitrogen donor atoms and the bridging [mu]--n1n2 and [mu]-n1n1 modes of the carboxylate ligands at the diiron(II) centers. Cyclic voltammograms of 1 and 2 displayed quasi-reversible redox couples at +16 and +108 mV vs. ferrocene/ferrocenium, respectively, assigned to metal-centered oxidations. Treatment of 2 with silver perchlorate afforded a silver(I)/diiron(III) heterotrimetallic complex, [Fe2([mu]-OH)2(CIO4)2(PIM)(ArTolCO2)Ag] (3), which was structurally and spectroscopically characterized. Complexes 1 and 2 both react rapidly with dioxygen. Oxygenation of 1 afforded a ([mu]-hydroxo)diiron(III) complex [Fe2([mu]- OH)(PIM)(Ph3CCO2)3] (4), a hexa([mu]-hydroxo)tetrairon(III) complex [Fe4([mu]- OH)6(PIM)2(Ph3CCO2)2] (5), and an unidentified iron(III) species. Oxygenation of 2 exclusively formed di(carboxylato)diiron(III) products. X-ray crystallographic and 57Fe Mössbauer spectroscopic investigations indicated that 2 reacts with dioxygen to give a mixture of ([mu]- oxo)diiron(III) [Fe2([mu]-O)(PIM)(ArTolCO2)2] (6) and di([mu]-hydroxo)diiron(III) [Fe2([mu]- OH)2(PIM)(ArTolCO2)2] (7) complexes in the same crystal lattice. Compounds 6 and 7 spontaneously convert to a tetrairon(III) complex, [Fe4([mu]-OH)6(PIM)2(ArTolCO2)2] (8), when treated with excess H2O. The possible biological implications of these findings are discussed. Chapter 4 To investigate how protons may be involved in the dioxygen activation pathway of non-heme diiron enzymes, the reaction of H+ with a synthetic ([mu]-1,2-peroxo)(carboxylato)diiron(III) complex was explored. Addition of an H+ donor to [Fe2(O2)(N-EtHPTB)(PhCO2)]2+ (1.O2, where N-EtHPTB = anion of N,N,N' ,N' -tetrakis(2-benzimidazolylmethyl)-2-hydroxy-1,3-diaminopropane) resulted in protonation of the carboxylate rather than the peroxo ligand. Mössbauer and resonance Raman spectroscopic measurements indicate that the Fe2(O2) core of the protonated complex [1.O2]H+ is identical to that of 1.O2. In contrast, the benzoate ligand of [1.O2]H+ displays significantly different IR and NMR spectral features relative to those of the starting complex. The [1.O2]H+ species can be converted back to 1.O2 upon treatment with base, indicating that protonation of the carboxylate is reversible. These findings suggest that in the reaction cycle of soluble methane monooxygenases and related diiron proteins, protons may 6 induce a carboxylate shift to enable substrate access to the diiron core and/or increase the electrophilicity of the oxygenated complex. Chapter 5 To explore additional methods to interrogate the properties of diiron protein intermediates, studies of the vibrational profiles of ([mu]-1,2-peroxo)diiron(III) species were pursued using nuclear resonance vibrational spectroscopy (NRVS). Comparison of the NRVS of [Fe2(O2)(NEtHPTB)(PhCO2)]2+ (1.O2) to that of the diiron(II) starting material [Fe2(N-EtHPTB)(PhCO2)]2+ (1) revealed that the oxygenated complex displays new frequencies above 350 cm-1, which are attributed to the Fe-O-O-Fe core vibrations based on 18O2/16O2 isotopic labeling studies. The peak at 338 cm-1 has not been previously observed by resonance Raman spectroscopy. Empirical normal mode analysis provides a qualitative description of these isotopic sensitive modes. The NRVS of [Fe2([mu]-O2)(HB(iPrpz)3)2(PhCH2CO2)2] (4.O2, where HB(iPrpz)3 = tris(3,5-diisopropylpyrazoyl) hydroborate) was also measured and shows several Fe2(O2) modes between 350-500 cm-1. Appendix A Attempts to prepare a diiron(IV) complex described in the literature led to several unexpected discoveries. Reaction of tris((3,5-dimethyl-4-methoxy)pyridyl-2-methyl)amine (R3TPA) with iron(III) perchlorate decahydrate and sodium hydroxide afforded a ([mu]-oxo)([mu]-hydroxo)diiron(III) [Fe2([mu]-O)([mu]-OH)(R3TPA)2](ClO4)3 complex (1), rather than [Fe2([mu]-O)(OH)(H2O)-(R3TPA)2](ClO4)3 (B) as previously reported. The putative diiron(III) starting material B is formed only at low temperature when excess water is present. Compound 1 hydrolyzes acetonitrile to acetate under ambient conditions. The acetate-bridged diiron compound, [Fe2([mu]- O)([mu]-CH3CO2)(R3TPA)2](ClO4)3 (4A), was characterized by X-ray crystallography as well as various spectroscopic methods and elemental analysis. The identity of the acetate bridged complex was confirmed by comparing the structural and spectroscopic characteristics of 4A to those of an independently prepared sample of [Fe2([mu]-O)([mu]-CH3CO2)(R3TPA)2](ClO4)3.

Download or read book Biomimetic Oxidations Catalyzed By Transition Metal Complexes written by Bernard Meunier and published by World Scientific. This book was released on 2000-03-08 with total page 697 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the classic work Metal-Catalyzed Oxidations of Organic Compounds (edited by R A Sheldon and J K Kochi, 1991), no book has been devoted to advances in the field of biomimetic oxidations, which was created nearly 18 years ago. This expanding research field is covered in this volume. All the different aspects of the modeling of oxidations catalyzed by metalloenzymes are dealt with.This invaluable book will be useful to postgraduates as well as researchers in academia and industry, and will also benefit second year university students.

Download or read book New Trends in Enzyme Catalysis and Biomimetic Chemical Reactions written by Gertz I. Likhtenshtein and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book is a view of enzyme catalysis by a physico-chemist with long-term experience in the investigation of structure and action mechanism of biological catalysts. This book is not intended to provide an exhaustive survey of each topic but rather a discussion of their theoretical and experimental background, and recent developments. The literature of enzyme catalysis is so vast and many scientists have made important contribution in the area, that it is impossible in the space allowed for this book to give a representative set of references. The author has tried to use reviews, and general principles of articles. He apologizes to those he has not been able to include. . ... The monograph is intended for scientists working on enzyme catalysis and adjacent areas such as chemical modeling of biological processes, homogeneous catalysis, biomedical research and biotechnology. The book can be use as a subsidiary manual for instructors, graduate and undergraduate students of university biochemistry and chemistry departments."--Pages ix-x.

Download or read book Model Complexes for Active Sites of Diiron Metalloproteins Dioxygen Reactivity and Water Effects written by Sungho Yoon and published by . This book was released on 2004 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) tetrairon(II) cubane complex was identified and structurally characterized. Chapter 4: Synthesis and Characterization of [Fe2 ... CR)]3 and [Fe2 ... CR)]3+ Complexes with Carboxylate-Rich Metal Coordination Environment as Models for Diiron Centers in Oxygen-Dependent Non-Heme Enzymes. Utilizing hydrogen bonding interactions and sterically bulky carboxylates, synthetic routes were developed to prepare the mononuclear iron(II) complexes with the vacant coordination sites for O2 binding. Reactions of such complexes with O2 resulted in rare asymmetric complexes having an [Fe2 ... CR)]3+ or [Fe2 ... CR)]3+ unit. These diiron(III) complexes with carboxylate-rich metal coordination environments reproduce the diiron(III) cores housed in four-helix bundles found in nature. Compound 3, which replicates the [Fe2 ... CR)] core of sMMOH[ox], shares several physical properties with the enzyme, electronic transitions, Mossbauer spectra, and magnetic exchange interactions. On the other hand, the structure of 4, ([mu]-oxo)([mu]-carboxylato)diiron(III) complex, mimics the diiron(III) sites of RNR-R2. The electronic and Mbssbauer spectral transitions of 4 are typical of diiron(III) complexes with an Fe-O-Fe moiety. Magnetic exchange coupling interaction between the two iron atoms is within the expected range for oxo-bridged diiron(III) sites. These results demonstrate how the diiron(III) structures in different metalloproteins, namely, the [mu]-oxo cores of RNR-R2 and the [mu]-dihydroxo unit in MMOH, can be replicated by subtle changes in ligand composition ...

Download or read book Aziridines and Epoxides in Organic Synthesis written by Andrei K. Yudin and published by John Wiley & Sons. This book was released on 2006-12-13 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aziridines and epoxides are among the most widely used intermediates in organic synthesis, acting as precursors to complex molecules due to the strains incorporated in their skeletons. Besides their importance as reactive intermediates, many biologically active compounds also contain these three-membered rings. Filling a gap in the literature, this clearly structured book presents the much needed information in a compact and concise way. The renowned editor has succeeded in gathering together excellent authors to cover synthesis, applications, and the biological aspects in equal depth. Divided roughly equally between aziridines and epoxides, the twelve chapters discuss: * Synthesis of aziridines * Nucleophilic ring-opening of aziridines and epoxides * Organic synthesis with aziridine building blocks * Vinyl aziridines in organic synthesis * Diastereoselective aziridination reagents * Synthetic aspects of aziridinomitocene chemistry * Biosynthesis of biologically important aziridines * Organic catalysis of epoxide and aziridine ring formation * Metal-mediated synthesis of epoxides * Asymmetric epoxide ring opening chemistry * Epoxides in complex molecule synthesis * Biological activity of epoxide-containing molecules A high-quality reference manual for academic and industrial chemists alike.

Download or read book Modern Oxidation Methods written by Jan-Erling Bäckvall and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: At the very latest, with the award of the 2001 Nobel Prize for work on asymmetric oxidation, there has been a need for a comprehensive book on such methods. Edited by J.-E. Backvall, one of the world's leaders in the field, this book fills that gap by covering the topic, from classical to green chemistry methods. He has put together a plethora of well-established authors from all over the world who cover every important aspect in high-quality contributions -- whether aerobic oxidation or transition metal-catalyzed epoxidation of alkenes. By providing an overview of this huge topic, this book represents an unparalleled aid for any chemist working in the field. Chapters include: Recent Developments in the Osmium-Catalyzed Dihydroxylation of Olefins Transition Metal-Catalyzed Epoxidation of Alkenes Organocatalytic Oxidation - Ketone-Catalyzed Asymmetric Epoxidation of Olefins Modern Oxidation of Alcohols using environmentally Benign Oxidants Aerobic Oxidations and Related Reactions Catalyzed by N-Hydroxyphthalimide Ruthenium-Catalyzed Oxidation of Alkenes, Alcohols, Amines, Amides, b-Lactams, Phenols, and Hydrocarbons Selective Oxidations of Sulfides and Amines Liquid Phase Oxidation Reactions Catalyzed by Polyoxometalates Oxidation of Carbonyl Compounds Mn-catalysed Oxidation with Hydrogen Peroxide

Download or read book The Activation of Dioxygen and Homogeneous Catalytic Oxidation written by D.H.R. Barton and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph consists of the proceedings of the Fifth International Symposium on the Activation of Dioxygen and Homogeneous Catalytic Oxidation, held in College Station, Texas, March 14-19, 1993. It contains an introductory chapter authored by Professors D. H. R. Barton and D. T. Sawyer, and twenty-nine chapters describing presentations by the plenary lecturers and invited speakers. One of the invited speakers, who could not submit a manuscript for reasons beyond his control, is represented by an abstract of his lecture. Also included are abstracts of forty-seven posters contributed by participants in the symposium. Readers who may wish to know more about the subjects presented in abstract form are invited to communicate directly with the authors of the abstracts. This is the fifth international symposium that has been held on this subject. The first was hosted by the CNRS, May 21-29, 1979, in Bendor, France (on the Island of Bandol). The second meeting was organized as a NATO workshop in Padova, Italy, June 24-27, 1984. This was followed by a meeting in Tsukuba, Japan, July 12-16, 1987. The fourth symposium was held at Balatonfured, Hungary, September 10-14, 1990. The sixth meeting is scheduled to take place in Delft, The Netherlands (late Spring, 1996); the organizer and host will be Professor R. A. Sheldon.

Download or read book Mechanical Catalysis written by Gerhard Swiegers and published by John Wiley & Sons. This book was released on 2008-10-03 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a clear and systematic description of the key role played by catalyst reactant dynamism including: (i) the fundamental processes at work, (ii) the origin of its general and physical features, (iii) the way it has evolved, and (iv) how it relates to catalysis in man-made systems. Unifies homogeneous, heterogeneous, and enzymatic catalysis into a single, conceptually coherent whole. Describes how to authentically mimic the underlying principles of enzymatic catalysis in man-made systems. Examines the origin and role of complexity and complex Systems Science in catalysis--very hot topics in science today.

Download or read book Journal written by American Chemical Society and published by . This book was released on 2004 with total page 1124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comprehensive Natural Products III written by and published by Elsevier. This book was released on 2020-07-22 with total page 4266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Natural Products III, Third Edition, Seven Volume Set updates and complements the previous two editions, including recent advances in cofactor chemistry, structural diversity of natural products and secondary metabolites, enzymes and enzyme mechanisms and new bioinformatics tools. Natural products research is a dynamic discipline at the intersection of chemistry and biology concerned with isolation, identification, structure elucidation, and chemical characteristics of naturally occurring compounds such as pheromones, carbohydrates, nucleic acids and enzymes. This book reviews the accumulated efforts of chemical and biological research to understand living organisms and their distinctive effects on health and medicine and to stimulate new ideas among the established natural products community. Provides readers with an in-depth review of current natural products research and a critical insight into the future direction of the field Bridges the gap in knowledge by covering developments in the field since the second edition published in 2010 Split into 7 sections on key topics to allow students, researchers and professionals to find relevant information quickly and easily Ensures that the knowledge within is easily understood by and applicable to a large audience

Download or read book Reactions of Unsymmetrical Diiron Complexes Bridged by Tetramethylfulvene Or Phosphido Ligand written by Hisako Hashimoto and published by . This book was released on 1995 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physical Inorganic Chemistry written by Andreja Bakac and published by John Wiley & Sons. This book was released on 2010-04-22 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt: This go-to text provides information and insight into physical inorganic chemistry essential to our understanding of chemical reactions on the molecular level. One of the only books in the field of inorganic physical chemistry with an emphasis on mechanisms, it features contributors at the forefront of research in their particular fields. This essential text discusses the latest developments in a number of topics currently among the most debated and researched in the world of chemistry, related to the future of solar energy, hydrogen energy, biorenewables, catalysis, environment, atmosphere, and human health.

Download or read book Modeling the Active Sites of Non heme Diiron Metalloproteins with Sterically Hindered Carboxylates and Syn N Donor Ligands written by Simone Friedle and published by . This book was released on 2009 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) These Mossbauer parameters are comparable to those observed for a peroxo intermediate formed in the reaction of reduced toluene/o-xylene monooxygenase hydroxylase (ToMOH) with dioxygen. Resonance Raman studies reveal an unusually low-energy 0-0 stretching mode in the peroxo intermediate that is consistent with a short diiron distance. Although peroxodiiron(lll) intermediates generated from 6, 7, and 8 are poor O-atom transfer catalysts, they display highly efficient catalase activity, with turnover numbers up to 10,000. In contrast to hydrogen peroxide reactions of diiron(Ill) complexes that lack a dinucleating ligand, the intermediates generated here could be reformed in significant quantities after a second addition of H20 2, as observed spectroscopically and by mass spectrometry. Appendix 1. Supporting Tables and Figures for Chapter 2 Appendix 2. Supporting Information for Chapter 4 Appendix 3. Synthesis of Triptycene Carboxylate-Bridged Dimetallic Complexes with First Row Transition Metals The synthesis and structural characterization of dimetallic complexes of the type [M2(1t-02CTrp) 4(THF)2] (M = Mn, Co, Ni, Cu, Zn) supported by triptycenecarboxylate ligands ( -O2CTrp) is described. Appendix 4. Synthesis and Structure of a Molecular Ferrous Wheel, [Fe(0 2CH)(O 2CArPro)(1,4-dioxane)]6 The structural characterization of a novel, hexanuclear iron(ll) compound with the carboxylate ArPrOCO2- is described.

Download or read book Methanotrophs written by Eun Yeol Lee and published by Springer Nature. This book was released on 2019-09-05 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers a comprehensive overview of the microbiological fundamentals and biotechnological applications of methanotrophs: aerobic proteobacteria that can utilize methane as their sole carbon and energy source. It highlights methanotrophs’ pivotal role in the global carbon cycle, in which they remove methane generated geothermally and by methanogens. Readers will learn how methanotrophs have been employed as biocatalysts for mitigating methane gas and remediating halogenated hydrocarbons in soil and underground water. Recently, methane has also attracted considerable attention as a potential next-generation carbon feedstock for industrial biotechnology, because of its abundance and low price. Methanotrophs can be used as biocatalysts for the production of fuels, chemicals and biomaterials including methanobactin from methane under environmentally benign production conditions. Sharing these and other cutting-edge insights, the book offers a fascinating read for all scientists and students of microbiology and biotechnology.

Download or read book Advances in the Development of Artificial Metalloenzymes written by Tatjana N. Parac-Vogt and published by Frontiers Media SA. This book was released on 2019-11-05 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reactions catalyzed by metalloenzymes have great potential for applications in the biotechnology and pharmaceutical industries. While only a few of these enzymes have yet been used in such applications, in the last few decades numerous efficient, selective, environmentally friendly and economical synthetic analogues have been described, including supramolecular, polymeric, nanoparticulate and lowmolecular- weight organometallic complexes, and metal organic frameworks. In this Research Topic, we present a collection of original research and review articles that show significant recent advances made in the rational design of such artificial metalloenzymes.

Download or read book Use of Sterically Hindered Carboxylate Ligands to Model Structural and Functional Features of Dioxygen activating Centers in Non heme Diiron Enzymes written by Dongwhan Lee and published by . This book was released on 2002 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) By using sterically hindered carboxylate ligands, 2,6-di(p-tolyl)benzoate (ArTolCO2- ) and 2,6-di(4-tert-butylphenyl)benzoate (Ar4-tBPhCO2- ), series of four-, five-, and six-coordinate iron(II) complexes were synthesized. The compounds are [Fe(O2CArTol)2(1-BnIm)2] (3), [Fe(O2CArTol)2(1-MeBzIm)2] (4), [Fe(02C-Ar4-tBuPh)2(2,2'-bipy)2] (5), [Fe(O2CArTol)2(TMEDA)] (6), and [Fe(O2CArTol)2(BPTA)] (7). Structural analyses of 3-7 revealed that the overall stereochemistry of the [Fe(O2CAr')2Ln] units is dictated by electronic and steric factors of the N-donor ligands (L), as well as by the flexible coordination of the carboxylate ligands. Distinctive MOss-Bauer parameters obtained for these and related compounds facilitated the spectral assignment of a diiron(II) complex having asymmetric metal sites, [Fe2(p-02CArTol)3(2CArTol)(2,6-lutidine)] (2). Well-defined mononuclear iron carboxylate complexes thus may serve as subsite models for higher nuclearity species in both synthetic and biological systems. Chapter III. Functional Mimic of Dioxygen-Activating Centers in Non-Heme Diiron Enzymes: Mechanistic Implications of Paramagnetic Intermediates in the Reactions between Diiron(II) Complexes and Dioxygen Tetracarboxylate diiron(II) complexes, [Fe2( -O02CArTOl)2(02CArToll)2(C5H5N)2] (la) and [Fe2(Pl-02CArTol)4(4-tBuC5H4N)2] (2a), where ArTloCO2- = 2,6-di(p-tolyl)benzoate, react with 02 in CH2C12 at -78 C to afford deep green intermediates ...