Author: Olaf Kühl
Publisher: Springer Science & Business Media
ISBN: 3540791183
Category : Science
Languages : en
Pages : 138
Get Book Here
Book Description
Nuclear Magnetic Resonance is a powerful tool, especially for the identification of 1 13 hitherto unknown organic compounds. H- and C-NMR spectroscopy is known and applied by virtually every synthetically working Organic Chemist. Con- quently, the factors governing the differences in chemical shift values, based on chemical environment, bonding, temperature, solvent, pH, etc. , are well understood, and specialty methods developed for almost every conceivable structural challenge. Proton and carbon NMR spectroscopy is part of most bachelors degree courses, with advanced methods integrated into masters degree and other graduate courses. In view of this universal knowledge about proton and carbon NMR spectr- copy within the chemical community, it is remarkable that heteronuclear NMR is still looked upon as something of a curiosity. Admittedly, most organic compounds contain only nitrogen, oxygen, and sulfur atoms, as well as the obligatory hydrogen and carbon atoms, elements that have an unfavourable isotope distribution when it comes to NMR spectroscopy. Each of these three elements has a dominant isotope: 14 16 32 16 32 N (99. 63% natural abundance), O (99. 76%), and S (95. 02%), with O, S, and 34 14 S (4. 21%) NMR silent. N has a nuclear moment I = 1 and a sizeable quadrupolar moment that makes the NMR signals usually very broad and dif cult to analyse.
Author: David G. Gorenstein
Publisher: Academic Press
ISBN: 0080918417
Category : Science
Languages : en
Pages : 619
Get Book Here
Book Description
Phosphorous-31 NMR: Principles and Applications focuses on the evolution of phosphorus-31 nuclear magnetic resonance (NMR) as a widely applied spectroscopic probe of the structure and dynamics of phosphorus-containing compounds. The selection first offers information on the principles and empirical observations of phosphorus-31 chemical shifts and the principles and applications of phosphorus-31 spin-spin coupling constants. Discussions focus on introduction and basic principles, directly bonded phosphorus coupling constants, and two-bond and three-bond coupling constants. The text then ponders on phosphorus-31 NMR of enzyme complexes and paramagnetic probes of enzyme complexes with phosphorus-containing compounds. The manuscript elaborates on the use of chiral thiophosphates and the stereochemistry of enzymatic phosphoryl transfer and DNA and RNA conformations. Topics include helix-coil transitions, sequence dependence of double-stranded DNA conformations, dynamic behavior of RNA and DNA, biological and genetic significance, and stereochemical problems studied with chiral thiophosphates. The conformation and dynamics of nucleic acids and phosphoproteins, relaxation behavior of nucleic acids, and theory and applications of solid-state phosphorus-31 NMR to nucleic acids are also discussed. The selection is a valuable reference for readers interested in the principles and applications of phosphorus-31 nuclear magnetic resonance.
Author: Louis D. Quin
Publisher: Wiley-VCH
ISBN:
Category : Science
Languages : en
Pages : 480
Get Book Here
Book Description
This is a methods-oriented book, which contains enormous amounts of information on 31P NMR, in a concise and well-edited format. It is an invaluable resource for every NMR spectroscopist. This book consists of 33 chapters, which together 'constitute a compendium that will be of optimal utility to the majority of 31P NMR spectroscopy users as well as to those perhaps not as familiar with the technique but curious about potential applications in their own research.' (From the editors' preface) There have been a number of new developments in NMR techniques in the 6 years since Verkade and Quin edited the first, successful book on 31P NMR. This new book does not supersede the previous book; it offers a wide cross-section of recent research. Compard to the first, basic, grounding volume, this book presents more results (it is more applied); it directly reflects a more mature science. Arguably, VCH has published the best NMR books in recent years (Neuhaus/Williamson, Croasmun/Carlson, etc.). This new addition to VCH's NMR list ensures the continued visibility and excellence of VCH in this field.
Author: John C. Tebby
Publisher: CRC Press
ISBN: 1351362038
Category : Science
Languages : en
Pages : 1140
Get Book Here
Book Description
To fully utilize Nuclear Magnetic Resonance (NMR) spectroscopy, a comprehensive and well-organized compilation of NMR data is necessary. While compilations have been available for other important NMR nuclei, such as carbon and fluorine, no comprehensive collection of data has been prepared for phosphorus-until now. The CRC Handbook of Phosphorus-31 Nuclear Magnetic Resonance Data provides a collection of 31P NMR chemical shifts for nearly 20,000 organic and inorganic phosphorus compounds. Each class of phosphorus compound is discussed. Bond types, stereochemistry (with the exception of metal complexes), media, important coupling constants, and data sources are included. The information is systematically organized according to coordination state, the atoms bound to phosphorus, and their connectivities. A comprehensive series of bar charts is also included to allow structure types to be assigned to chemical shift data. This handbook is an invaluable resource for all scientists working with phosphorus compounds, including chemists, biochemists, medical researchers, and pharmaceutical chemists.
Author: Paul S. Pregosin
Publisher: Springer Science & Business Media
ISBN: 3642488307
Category : Science
Languages : en
Pages : 164
Get Book Here
Book Description
For almost a quarter of a century the words "nuclear magnetic reso nance" were synonymous with proton I,leasurements. During this period the literature abounded with a seemingly infinite variety of 1H NHR studies concerned primarily with carbon chemistry. Occasionally a "novel" nucleus was studied and, even in those early days, the poten- 13 14 31 19 tial offered by C, N, P and F was clearly recognized. Despite the allure, the technical difficulties involved in measuring some of these nuclei were far from trivial. Small magnetic moments and low natural abundance in combination with spin-spin coupling from other nuclei, mostly protons, resulted in a signal-to-noise problem whose severity effectively excluded the study of metal complexes with unfa vorable solubility characteristics. The first important breakthrough came with the advent of broad band 1H-decoupling. For example, the featureless broad 31p resonance associated with the commonly used ligand triphenyl phosphine is converted to a sharp, more readily ob served singlet when wide-band decoupling is employed (see Fig. 1). Despite this improvement investigation of more interesting molecules, such as catalytically active complexes was forced to await the devel opment of Fourier Transform methods since only with relatively rapid signal averaging methods could sufficient signal-to-noise ratios be achieved.
Author: Kolio D. Troev
Publisher: Elsevier
ISBN: 008047649X
Category : Science
Languages : en
Pages : 308
Get Book Here
Book Description
Chemistry and Application of H-Phosphonates is an excellent source for those planning the synthesis of new phosphorus-containing compounds and in particular derivatives containing a phosphonate, phosphoramide or phosphonic acid diester group. The rich chemistry, low cost and easy availability of diesters of H-phosphonic acid makes them an excellent choice as synthone in a number of practically important reactions. Phosphonic acid esters are intermediates in the synthesis of important classes of compounds such as alpha-aminophosphonic acids, bisphosphonates, epoxyalkylphosphonates, alpha-hydroxyalkylphosphonates, phosphoramides, poly(alkylene H-phosphonate)s, poly(alkylene phosphate)s, nucleoside H-phosphonates. The synthesis of each of these compound classes is reviewed in detail. Alpha-Aminophosphonic acids are an important class of biologically active compounds, which have received an increasing amount of attention because they are considered to be structural analogues of the corresponding Alpha-amino acids. The utilities of alpha-aminophosphonates as peptide mimics, haptens of catalytic antibodies, enzyme inhibitors, inhibitors of cancers, tumours, viruses, antibiotics and pharmacologic agents are well documented. Alpha-Hydroxyalkanephosphonates are compounds of significant biological and medicinal applications. Dialkyl epoxyalkylphosphonates are of interest because of their use as intermediates in the synthesis of bioactive substances, and as modifiers of natural and synthetic polymers. Bisphosphonates are drugs that have been widely used in different bone diseases, and have recently been used successfully against many parasites. Poly(alkylene H-phosphonate)s and poly(alkylene phosphate)s are promising, biodegradable, water soluble, new polymer-carriers of drugs. Nucleoside H-phosphonates seem to be the most attractive candidates as starting materials in the chemical synthesis of DNA and RNA fragments. The 5'-hydrogen phosphonate-3'-azido-2',3'-dideoxythimidine is one of the most significant anti-HIV prodrug, which is currently in clinical trials. Chapters review the synthesis; physical and spectral properties (1H, 13C, 31P and 17O NMR data); characteristic reactions; important classes of compounds based on these esters of H-phosphonic acid; their application as physiologically active substances, flame retardants, catalysts, heat and light stabilizers, lubricants, scale inhibitors, polymer-carriers of drugs; preparation of H-phosphonate diesters and general procedures for conducting the most important reactions.* provides ideas for the synthesis of phosphonates, phosphoramides and diesters of phosphonic acid (new phosphorus-containing compounds)* reviews structure, spectra and biological activity of H-phosphonates and their derivatives* examines new areas of application of phosphorus-containing compounds
Author: Viktor Iaroshenko
Publisher: John Wiley & Sons
ISBN: 3527335722
Category : Science
Languages : en
Pages : 586
Get Book Here
Book Description
Filling the gap for an up-to-date reference that presents the field of organophosphorus chemistry in a comprehensive and clearly structured way, this one-stop source covers the chemistry, properties, and applications from life science and medicine. Divided into two parts, the first presents the chemistry of various phosphorus-containing compounds and their synthesis, including ylides, acids, and heterocycles. The second part then goes on to look at applications in life science and bioorganic chemistry. Last but not least, such important practical aspects as 31P-NMR and protecting strategies for these compounds are presented. For organic, bioinorganic, and medicinal chemists, as well as those working on organometallics, and for materials scientists. The book, a contributed work, features a team of renowned scientists from around the world whose expertise spans the many aspects of modern organophosphorus chemistry.
Author: M. Witanowski
Publisher: Springer Science & Business Media
ISBN: 1468481754
Category : Science
Languages : en
Pages : 406
Get Book Here
Book Description
To date nitrogen NMR has been discussed in research papers and review articles throughout the scientific literature. It has been our aim in preparing this book to provide a comprehen sive account of the widely spread applications of nitrogen NMR. The relevant literature has been surveyed from the beginnings of NMR until early 1972. The steady annual growth in the number of references cited since 1965 is ample evidence of the ever increasing importance of the subject. Sufficient theoretical and experimental background is given for an understanding of the applications dealt with in later chapters. The basic principles of NMR are developed with a theoretical approach to chemical shifts and spin-spin coupling constants, particular emphasis being given to nitrogen nuclei. Following this the experimental aspects of nitrogen NMR are adequately described. Special emphasis is given to the observable effects of the nuclear quadrupole moment of the 14 N nucleus. It is appro priate that this topic be dealt with in depth since quadrupolar interactions frequently dominate the information available from a study of the 14 N nucleus and other nuclei spin coupled to it. The applications of nitrogen chemical shift data to organic and inorganic molecules are covered in two extensive chapters which include the effects of paramagnetism on nitrogen NMR.
Author: William Kemp
Publisher: Free Press
ISBN: 9780029494011
Category : Nuclear magnetic resonance spectroscopy
Languages : en
Pages : 240
Get Book Here
Book Description
Author: Neil E. Jacobsen
Publisher: John Wiley & Sons
ISBN: 1119047145
Category : Science
Languages : en
Pages : 652
Get Book Here
Book Description
Through numerous examples, the principles of the relationship between chemical structure and the NMR spectrum are developed in a logical, step-by-step fashion Includes examples and exercises based on real NMR data including full 600 MHz one- and two-dimensional datasets of sugars, peptides, steroids and natural products Includes detailed solutions and explanations in the text for the numerous examples and problems and also provides large, very detailed and annotated sets of NMR data for use in understanding the material Describes both simple aspects of solution-state NMR of small molecules as well as more complex topics not usually covered in NMR books such as complex splitting patterns, weak long-range couplings, spreadsheet analysis of strong coupling patterns and resonance structure analysis for prediction of chemical shifts Advanced topics include all of the common two-dimensional experiments (COSY, ROESY, NOESY, TOCSY, HSQC, HMBC) covered strictly from the point of view of data interpretation, along with tips for parameter settings
