Download or read book Separated Local Field NMR Spectroscopy In Partially Ordered Systems New Methodologies And Applications written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Dipolar couplings are one of the major source of structural information. Due to their dependence on the distance between the nuclei and the angle of orientation of the dipolar vector with respect to the magnetic field, they provide significant insight into the geometry and topology of molecules. As the dipolar interactions are in general present in the solid phase of the compounds, solid state NMR experiments have gained significant popularity and is widely used. Separated Local Field NMR spectroscopy based on cross-polarization technique has been used to measure the heteronuclear dipolar couplings in solid state. However, the technique undergoes many experimental challenges and requires further development. This thesis is concerned mainly with the development of techniques to measure the dipolar couplings accurately in oriented molecules. In this regard, a method for fast data acquisition is also proposed. The first chapter briefly introduces the basics of NMR spectroscopy, methodologies applied for obtaining a high resolution NMR spectrum in the solid state. An introduction to liquid crystals is presented and the nature of NMR interaction in the liquid crystalline phases is described. In chapter-2, a new pulse scheme has been proposed that includes the X-nucleus polarization in the SLF experiments and is shown to provide better sensitivity and resolution. A quantitative analysis with simulation and experimental results are also presented. In chapter-3, the performance of various homonuclear decoupling pulse schemes incorporated into SLF experiments tested on oriented systems are compared. The proposed pulse schemes are shown to provide high resolution spectrum with accurate dipolar coupling measurement for natural abundant samples and for uniformly labeled compounds as well. Theoretical description with simulation and experimental results shown here are found to provide optimum results under several technical complications seen with respect to the conventional met.
Download or read book Development of New Signal Processing and Mixture Separation Techniques for Nuclear Magnetic Resonance Spectroscopy Applications written by Hasan Celik and published by . This book was released on 2011 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although originally designed to treat neither spectroscopic nor multidimensional data, FDM was adapted to process NMR spectra of both large and small molecules in liquids in 1D, 2D, 3D, and 4D spectra, with the multidimensional cases requiring important modifications. FDM outperforms the discrete Fourier Transform (DFT) whenever sensitivity is good, the spectrum is sufficiently sparse, the spectral peaks are sharp and Lorentzian, and the extent of the measured time-domain data is short, so that the FT spectrum exhibits line shapes that are distorted only by the time-frequency uncertainty principle. A further study of FDM to perturbations under non-ideal conditions lead to further improvements and finally a multi-dimensional, phase-sensitive, hybrid FDM (HFDM) algorithm that is introduced for the first time. HFDM can enhance the resolution of peaks distorted by time-frequency uncertainty, while still producing a spectrum in which all the original imperfections are present, such that a true noise floor prevents inadvertent contouring of features that look like resonances but that would in fact be buried in noise in any decent spectral estimate. This opens the door to the application of HFDM on NMR data sets with more reliability. Mixture separation is another important area of NMR research and will be the focus of the third chapter. Separating a mixture of signals into its source components is an engaging but challenging problem relevant to research in a wide variety of fields from neurology and medical signal processing to speech recognition systems. The vast majority of NMR spectroscopic data is taken on isolated, purified compounds; yet mixtures are clearly important to tackle. The pharmaceutical industry is a key example of a field that would benefit tremendously from more robust NMR mixture separation techniques. Structural information about promising candidates from the drug design process must be extracted from samples that also contain the target molecule, side products, and impurities. NMR can identify individual samples with respect to their unique fingerprint spectra; however, it has been traditionally poor at handling mixtures. Diffusion ordered spectroscopy (DOSY) has been one of the few NMR techniques that can be used for mixture separation. It uses translational diffusion to effect a partial separation and can be quite powerful when the individual compounds have a distinguishable difference in their diffusion constants. However, the separation problem becomes more difficult when the component molecules have similar chemical functional group and overlap in their NMR spectra. Blind Source Separation (BSS) is a technique that can be used to extract an individual NMR subspectrum from spectra of a number of different mixtures; and--if the molecules do not interact strongly--these individual subspectra adhere closely to those of the corresponding pure compounds under the same conditions. Furthermore, the "mixture spectra" need not be different physical samples: any method that can modify the intensities of all the peaks from a given molecule, in concert, is applicable. Previously a mixture of two components was successfully separated. Recent efforts have uncovered a flaw in the original BSS algorithm that causes behaves erratically for samples with three or more components. This complication will be described in detail, and a newly developed approach-- dubbed "BISI" for Blind Iterative Source Identification--will be introduced that overcomes those previously unforeseen problems.
Download or read book Modern Methods in Solid state NMR written by Paul Hodgkinson and published by Royal Society of Chemistry. This book was released on 2018-04-05 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solid-state NMR covers an enormous range of material types and experimental techniques. Although the basic instrumentation and techniques of solids NMR are readily accessible, there can be significant barriers, even for existing experts, to exploring the bewildering array of more sophisticated techniques. In this unique volume, a range of experts in different areas of modern solid-state NMR explain about their area of expertise, emphasising the “practical aspects” of implementing different techniques, and illustrating what questions can and cannot be addressed. Later chapters address complex materials, showing how different NMR techniques discussed in earlier chapters can be brought together to characterise important materials types. The volume as a whole focusses on topics relevant to the developing field of “NMR crystallography” – the use of solids NMR as a complement to diffraction crystallography. This book is an ideal complement to existing introductory texts and reviews on solid-state NMR. New researchers wanting to understand new areas of solid-state NMR will find each chapter to be the equivalent to spending time in the laboratory of an internationally leading expert, learning the hints and tips that make the difference between knowing about a technique and being ready to put it into action. With no equivalent on the market, it will be of interest to every solid-state NMR researcher (academic and postgraduate) working in the chemical sciences.
Download or read book Nuclear Magnetic Resonance written by G A Webb and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a spectroscopic method, Nuclear Magnetic Resonance (NMR) has seen spectacular growth over the past two decades, both as a technique and in its applications. Today the applications of NMR span a wide range of scientific disciplines, from physics to biology to medicine. Each volume of Nuclear Magnetic Resonance comprises a combination of annual and biennial reports which together provide comprehensive of the literature on this topic. This Specialist Periodical Report reflects the growing volume of published work involving NMR techniques and applications, in particular NMR of natural macromolecules which is covered in two reports: "NMR of Proteins and Acids" and "NMR of Carbohydrates, Lipids and Membranes". For those wanting to become rapidly acquainted with specific areas of NMR, this title provides unrivalled scope of coverage. Seasoned practitioners of NMR will find this an in valuable source of current methods and applications. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.
Download or read book Biological NMR Spectroscopy written by John L. Markley and published by Oxford University Press. This book was released on 1997-01-30 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a critical assessment of progress on the use of nuclear magnetic resonance spectroscopy to determine the structure of proteins, including brief reviews of the history of the field along with coverage of current clinical and in vivo applications. The book, in honor of Oleg Jardetsky, one of the pioneers of the field, is edited by two of the most highly respected investigators using NMR, and features contributions by most of the leading workers in the field. It will be valued as a landmark publication that presents the state-of-the-art perspectives regarding one of today's most important technologies.
Download or read book Experimental Approaches of NMR Spectroscopy written by The Nuclear Magnetic Resonance Society of Japan and published by Springer. This book was released on 2017-11-23 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the advanced developments in methodology and applications of NMR spectroscopy to life science and materials science. Experts who are leaders in the development of new methods and applications of life and material sciences have contributed an exciting range of topics that cover recent advances in structural determination of biological and material molecules, dynamic aspects of biological and material molecules, and development of novel NMR techniques, including resolution and sensitivity enhancement. First, this book particularly emphasizes the experimental details for new researchers to use NMR spectroscopy and pick up the potentials of NMR spectroscopy. Second, the book is designed for those who are involved in either developing the technique or expanding the NMR application fields by applying them to specific samples. Third, the Nuclear Magnetic Resonance Society of Japan has organized this book not only for NMR members of Japan but also for readers worldwide who are interested in using NMR spectroscopy extensively.
Download or read book Journal written by American Chemical Society and published by . This book was released on 2003 with total page 990 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Magnetic Resonance written by I. Barsukov and published by Royal Society of Chemistry. This book was released on 2000 with total page 587 pages. Available in PDF, EPUB and Kindle. Book excerpt: For those wanting to become rapidly acquainted with specific areas of NMR, this title provides unrivalled scope of coverage.
Download or read book Solid State NMR Spectroscopy written by Melinda J. Duer and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is for those familiar with solution-state NMR who are encountering solid-state NMR for the first time. It presents the current understanding and applications of solid-state NMR with a rigorous but readable approach, making it easy for someone who merely wishes to gain an overall impression of the subject without details. This dual requirement is met through careful construction of the material within each chapter. The book is divided into two parts: "Fundamentals" and "Further Applications." The section on Fundamentals contains relatively long chapters that deal with the basic theory and practice of solid-state NMR. The essential differences and extra scope of solid-state NMR over solution-state is dealt with in an introductory chapter. The basic techniques that all chapters rely on are collected into a second chapter to avoid unnecessary repetition later. Remaining chapters in the "Fundamentals" part deal with the major areas of solid-state NMR which all solid-state NMR spectroscopists should know about. Each begins with an overview of the topic that puts the chapter in context. The basic principles upon which the techniques in the chapter rely are explained in a separate section. Each of these chapters exemplifies the principles and techniques with the applications most commonly found in current practice. The "Further Applications" section contains a series of shorter chapters which describe the NMR techniques used in other, more specific areas. The basic principles upon which these techniques rely will be expounded only if not already in the Fundamentals part.
Download or read book Polymer Science A Comprehensive Reference written by and published by Newnes. This book was released on 2012-12-05 with total page 7752 pages. Available in PDF, EPUB and Kindle. Book excerpt: The progress in polymer science is revealed in the chapters of Polymer Science: A Comprehensive Reference, Ten Volume Set. In Volume 1, this is reflected in the improved understanding of the properties of polymers in solution, in bulk and in confined situations such as in thin films. Volume 2 addresses new characterization techniques, such as high resolution optical microscopy, scanning probe microscopy and other procedures for surface and interface characterization. Volume 3 presents the great progress achieved in precise synthetic polymerization techniques for vinyl monomers to control macromolecular architecture: the development of metallocene and post-metallocene catalysis for olefin polymerization, new ionic polymerization procedures, and atom transfer radical polymerization, nitroxide mediated polymerization, and reversible addition-fragmentation chain transfer systems as the most often used controlled/living radical polymerization methods. Volume 4 is devoted to kinetics, mechanisms and applications of ring opening polymerization of heterocyclic monomers and cycloolefins (ROMP), as well as to various less common polymerization techniques. Polycondensation and non-chain polymerizations, including dendrimer synthesis and various "click" procedures, are covered in Volume 5. Volume 6 focuses on several aspects of controlled macromolecular architectures and soft nano-objects including hybrids and bioconjugates. Many of the achievements would have not been possible without new characterization techniques like AFM that allowed direct imaging of single molecules and nano-objects with a precision available only recently. An entirely new aspect in polymer science is based on the combination of bottom-up methods such as polymer synthesis and molecularly programmed self-assembly with top-down structuring such as lithography and surface templating, as presented in Volume 7. It encompasses polymer and nanoparticle assembly in bulk and under confined conditions or influenced by an external field, including thin films, inorganic-organic hybrids, or nanofibers. Volume 8 expands these concepts focusing on applications in advanced technologies, e.g. in electronic industry and centers on combination with top down approach and functional properties like conductivity. Another type of functionality that is of rapidly increasing importance in polymer science is introduced in volume 9. It deals with various aspects of polymers in biology and medicine, including the response of living cells and tissue to the contact with biofunctional particles and surfaces. The last volume is devoted to the scope and potential provided by environmentally benign and green polymers, as well as energy-related polymers. They discuss new technologies needed for a sustainable economy in our world of limited resources. Provides broad and in-depth coverage of all aspects of polymer science from synthesis/polymerization, properties, and characterization methods and techniques to nanostructures, sustainability and energy, and biomedical uses of polymers Provides a definitive source for those entering or researching in this area by integrating the multidisciplinary aspects of the science into one unique, up-to-date reference work Electronic version has complete cross-referencing and multi-media components Volume editors are world experts in their field (including a Nobel Prize winner)
Download or read book NMR of Quadrupolar Nuclei in Solid Materials written by Roderick E. Wasylishen and published by John Wiley & Sons. This book was released on 2012-12-19 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: NMR OF QUADRUPOLAR NUCLEI IN SOLID MATERIALS Over the past 20 years technical developments in superconducting magnet technology and instrumentation have increased the potential of NMR spectroscopy so that it is now possible to study a wide range of solid materials. In addition, one can probe the nuclear environments of many other additional atoms that possess the property of spin. In particular, it is possible to carry out NMR experiments on isotopes that have nuclear spin greater that 1⁄2 (i.e. quadrupolar nuclei). Since more that two-thirds of all NMR active isotopes are quadrupolar nuclei, applications of NMR spectroscopy with quadrupolar nuclei are increasing rapidly. The purpose of this handbook is to provide under a single cover the fundamental principles, techniques and applications of quadrupolar NMR as it pertains to solid materials. Each chapter has been prepared by an expert who has made significant contributions to out understanding and appreciation of the importance of NMR studies of quadrupolar nuclei in solids. The text is divided into three sections: The first provides the reader with the background necessary to appreciate the challenges in acquiring and interpreting NMR spectra of quadrupolar neclei in solids. The second presents cutting-edge techniques and methodology for employing these techniques to investigate quadrupolar nuclei in solids. The final section explores applications of solid-state NMR studies of solids ranging from investigations of dynamics, characterizations of biological samples, organic and inorganic materials, porous materials, glasses, catalysts, semiconductors and high-temperature superconductors. About EMR Handbooks The Encyclopedia of Magnetic Resonance (EMR) publishes a wide range of online articles on all aspects of magnetic resonance in physics, chemistry, biology and medicine. The existence-of this large number of articles, written by experts in various fields, is enabling the publication of a series of EMR Handbooks on specific areas of NMR and MRI. The chapters of each of these handbooks will comprise a carefully chosen selection of Encyclopedia articles. In consultation with the EMR Editorial Board, the EMR Handbooks are coherently planned in advance by specially-selected Editors, and new articles, are written (together with updates of some already existing articles) to give appropriate complete coverage. The handbooks are intended to be of value and interest to research students, postdoctoral fellows and other researchers learning about the scientific area in question and undertaking relevant experiments, whether in academia or industry. Have the content of this handbook and the complete content of the Encyclopedia of Magnetic Resonance at your fingertips! Visit: www.wileyonlinelibrary.com/ref/emr
Download or read book Compact NMR written by Bernhard Blümich and published by Walter de Gruyter GmbH & Co KG. This book was released on 2014-08-22 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this book is to provide an introduction to the practical use of mobile NMR at a level as basic as the operation of a smart phone. Each description follows the same didactic pattern: introduction, basic theory, pulse sequences and parameters, beginners-level measurements, advanced-level measurements, and data processing. Nuclear Magnetic Resonance (NMR) spectroscopy is the most popular method for chemists to analyze molecular structures while Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool for medical doctors that provides high-contrast images of biological tissue depicting the brain function and the beating heart. In both applications large super-conducting magnets are employed which magnetize atomic nuclei of an object positioned inside the magnet. Their circulating motion is interrogated by radio-frequency waves. Depending on the operating mode, the frequency spectrum provides the chemist with molecular information, the medical doctor with anatomic images, while the materials scientist is interested in NMR relaxation parameters, which scale with material properties and determine the contrast in magnetic resonance images. Recent advances in magnet technology led to a variety of small permanent magnets, by which NMR spectra, images, and relaxation parameters can be measured with mobile and low-cost instruments.
Download or read book Carbon 13 NMR Spectroscopy written by Eberhard Breitmaier and published by Wiley-VCH. This book was released on 1987 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: E. Breitmaier, W. Voelter Carbon-13 NMR Spectroscopy High-Resolution Methods and Applications in Organic Chemistry and Biochemistry Third, completely revised edition New techniques and increased use of computers have led to rapid development in 13C NMR spectroscopy with enhanced instrumental sensitivity and improved quality of the spectra. This necessitated a complete revision when the third edition of this successful monograph was prepared. The new methods described include those for multiplicity analysis and two-dimensional homo- or hetero-nuclear shift correlations. As in the second edition, the authors survey the large number of 13C NMR applications to organic molecules and natural products in a representative and systematic rather than an exhaustive way. New sections about coupling constants, organophosphorus and organometallic compounds as well as synthetic polymers have been added. The scope remains limited to high-resolution methods and molecular systems.
Download or read book Physics Briefs written by and published by . This book was released on 1993 with total page 1212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NMR of Ordered Liquids written by Elliott Burnell and published by Springer Science & Business Media. This book was released on 2003-07-31 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: NMR of Ordered Liquids gives a unique overview of the scope and limitations of the NMR of oriented liquids, based on contributions from acknowledged experts in the field. The book consists of four sections: -detailed general introduction which covers the basic principles and sophisticated experimental techniques; -wide variety of applications ranging from NMR studies of small atoms and molecules in anisotropic liquids to the utilization of residual dipolar couplings for structure determination of biological molecules; -summary of the sophisticated theoretical treatments, computer simulations, and phenomenological models for anisotropic intermolecular interactions that are widely used in the analysis of experimental results; -overview of the dynamical aspects and relaxation processes relevant for orientationally ordered molecules.
Download or read book Amorphous Solid Dispersions written by Navnit Shah and published by Springer. This book was released on 2014-11-21 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume offers a comprehensive guide on the theory and practice of amorphous solid dispersions (ASD) for handling challenges associated with poorly soluble drugs. In twenty-three inclusive chapters, the book examines thermodynamics and kinetics of the amorphous state and amorphous solid dispersions, ASD technologies, excipients for stabilizing amorphous solid dispersions such as polymers, and ASD manufacturing technologies, including spray drying, hot melt extrusion, fluid bed layering and solvent-controlled micro-precipitation technology (MBP). Each technology is illustrated by specific case studies. In addition, dedicated sections cover analytical tools and technologies for characterization of amorphous solid dispersions, the prediction of long-term stability, and the development of suitable dissolution methods and regulatory aspects. The book also highlights future technologies on the horizon, such as supercritical fluid processing, mesoporous silica, KinetiSol®, and the use of non-salt-forming organic acids and amino acids for the stabilization of amorphous systems. Amorphous Solid Dispersions: Theory and Practice is a valuable reference to pharmaceutical scientists interested in developing bioavailable and therapeutically effective formulations of poorly soluble molecules in order to advance these technologies and develop better medicines for the future.
Download or read book LC NMR written by Nina C. Gonnella and published by CRC Press. This book was released on 2020-01-15 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: The isolation and structural characterization of substances present at very low concentrations, as is necessary to satisfy regulatory requirements for pharmaceutical drug degradants and impurities, can present scientific challenges. The coupling of HPLC with NMR spectroscopy has been at the forefront of cutting-edge technologies to address these issues. LC-NMR: Expanding the Limits of Structure Elucidation presents a comprehensive overview of key concepts in HPLC and NMR that are required to achieve definitive structure elucidation with very low levels of analytes. Because skill sets from both of these highly established disciplines are involved in LC-NMR, the author provides introductory background to facilitate readers’ proficiency in both areas, including an entire chapter on NMR theory. The much-anticipated second edition provides guidance in setting up LC-NMR systems, discussion of LC methods that are compatible with NMR, and an update on recent hardware and software advances for system performance, such as improvements in magnet design, probe technology, and solvent suppression techniques that enable unprecedented mass sensitivity in NMR. This edition features methods to quantify concentration and assess purity of isolated metabolites on the micro scale and incorporates computational approaches to accelerate the structure elucidation process. The author also includes implementation and application of qNMR and automated and practical use of computational chemistry combined with QM and DFT to predict highly accurate NMR chemical shifts. The text focuses on current developments in chromatographic-NMR integration, with particular emphasis on utility in the pharmaceutical industry. Applications include trace analysis, analysis of mixtures, and structural characterization of degradation products, impurities, metabolites, peptides, and more. The text discusses novel uses and emerging technologies that challenge detection limits as well future directions for this important technique. This book is a practical primary resource for NMR structure determination—including theory and application—that guides the reader through the steps required for isolation and NMR structure elucidation on the micro scale.
