Nuclear Magnetic Resonance Spectroscopy of Boron Compounds

Nuclear Magnetic Resonance Spectroscopy of Boron Compounds PDF Author: Heinrich Nöth
Publisher: Springer Science & Business Media
ISBN: 3642667570
Category : Science
Languages : en
Pages : 474

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Book Description
The revolutionary impetus of the NMR methods in organic chemistry has parallels in the field of boron chemistry. lIB NMR spectroscopy provided a basis for the elucida tion of structures and reactions of the boron hydrides. However, although many studies have been carried out with the higher boranes, carboranes, metalloboranes, etc. , and although certain patterns have emerged, the correlation between the observed chemical shift and the assigned structural unit is still not fully understood. Therefore, predictions in this area are still rather limited, and semiquantitative interpretations are not yet pos sible. Several years ago Eaton and Lipscomb sUpImarized the status in this field in their book "NMR Studies of Boron Hydrides and Related Compounds" and a plethora of new data has accumulated since then. The book also contained material on simple bo rane derivatives, but they were not discussed in any detail. On the other hand many systematic studies, both synthetic and spectroscopic, have been conducted on these simple boron materials in the last decade. Thus a large amount of NMR information is available, not only on lIB but also on 1 H, 1 3 C, and 14 N. However, this information is widely scattered in the literature, and often the data are not discussed at all. It see med appropriate, therefore, to collect these data and to present them in one volume.

Nuclear Magnetic Resonance Spectroscopy of Boron Compounds

Nuclear Magnetic Resonance Spectroscopy of Boron Compounds PDF Author: Heinrich Nöth
Publisher: Springer Science & Business Media
ISBN: 3642667570
Category : Science
Languages : en
Pages : 474

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Book Description
The revolutionary impetus of the NMR methods in organic chemistry has parallels in the field of boron chemistry. lIB NMR spectroscopy provided a basis for the elucida tion of structures and reactions of the boron hydrides. However, although many studies have been carried out with the higher boranes, carboranes, metalloboranes, etc. , and although certain patterns have emerged, the correlation between the observed chemical shift and the assigned structural unit is still not fully understood. Therefore, predictions in this area are still rather limited, and semiquantitative interpretations are not yet pos sible. Several years ago Eaton and Lipscomb sUpImarized the status in this field in their book "NMR Studies of Boron Hydrides and Related Compounds" and a plethora of new data has accumulated since then. The book also contained material on simple bo rane derivatives, but they were not discussed in any detail. On the other hand many systematic studies, both synthetic and spectroscopic, have been conducted on these simple boron materials in the last decade. Thus a large amount of NMR information is available, not only on lIB but also on 1 H, 1 3 C, and 14 N. However, this information is widely scattered in the literature, and often the data are not discussed at all. It see med appropriate, therefore, to collect these data and to present them in one volume.

Principles of High Resolution NMR in Solids

Principles of High Resolution NMR in Solids PDF Author: M. Mehring
Publisher: Springer Science & Business Media
ISBN: 3642687563
Category : Science
Languages : en
Pages : 352

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Book Description
The field of Nuclear Magnetic Resonance (NMR) has developed at a fascinating pace during the last decade. It always has been an extremely valuable tool to the organic chemist by supplying molecular "finger print" spectra at the atomic level. Unfortunately the high resolution achievable in liquid solutions could not be obtained in solids and physicists and physical chemists had to live with unresolved lines open to a wealth of curve fitting procedures and a vast amount of speculations. High resolution NMR in solids seemed to be a paradoxon. Broad structure less lines are usually encountered when dealing with NMR in solids. Only with the recent advent of mUltiple pulse, magic angle, cross-polarization, two-dimen sional and multiple-quantum spectroscopy and other techniques during the last decade it became possible to resolve finer details of nuclear spin interactions in solids. I have felt that graduate students, researchers and others beginning to get involved with these techniques needed a book which treats the principles, theo retical foundations and applications of these rather sophisticated experimental techniques. Therefore I wrote a monograph on the subject in 1976. Very soon new ideas led to the developement of "two-dimensional spectroscopy" and "multiple-quantum spectroscopy", topics which were not covered in the first edition of my book. Moreover an exponential growth of literature appeared in this area of research leaving the beginner in an awkward situation of tracing back from a current article to the roots of the experiment.

Compact NMR

Compact NMR PDF Author: Bernhard Blümich
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 3110374587
Category : Technology & Engineering
Languages : en
Pages : 305

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Book Description
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.

High Resolution NMR Spectroscopy in Solids

High Resolution NMR Spectroscopy in Solids PDF Author: M. Mehring
Publisher: Springer Science & Business Media
ISBN: 3642963323
Category : Science
Languages : en
Pages : 257

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Book Description
Manipulation and Dilution Tools for Ruling Abundant Species "NMR is dead" was the slogan heard in the late 1960s at least among physicists, until John S. Waugh and his co-workers initiated a series of new NMR experiments, which employed the coherent modulation of interactions by strong radiofrequency fields. A wealth of new phenomena was observed, which are summarized in the introduction for the convenience of the unbiased reader, whereas Section 2 collects the basic spin interactions observed in solids. Line-narrowing effects in dipolar coupled solids by the application of multiple pulse experiments are extensively discussed in Section 3. Numerous extensions of the basic Waugh, Huber, and Haeberlen experiment have been developed by different groups and have been applied to the nuclei IH, 9Be, 19F, 27Al, 31p, 63CU in solids. Application of this technique to a variety of systems is still in progress and should reveal interesting insights into weak spin interactions in solids. It was soon realized that rare spins could be used as monitors for molecular fields in the solid state; however, rare spin observation is difficult because of the small signal-to-noise ratio. Pines, Gibby, and Waugh introduced a new concept of cross-polarization, based on ideas of Hahn and co-workers, which allows the detection ofrare spins with increased sensitivity. The dynamics involved are treated in detail. Other sections merely list results obtained by the techniques described and demonstrate their usefulness in the investigation of dynamical problems in molec ular and solid state physics.

Dynamic NMR Spectroscopy

Dynamic NMR Spectroscopy PDF Author:
Publisher: Springer Science & Business Media
ISBN: 3642669611
Category : Science
Languages : en
Pages : 220

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Book Description
Since the first successful NMR experiments in 1946 it was well appreciated that dynamic processes play an important role in the NMR spectroscopy of bulk matter [1]. Early theories on the dependence of the relaxation parameters Tl and T2 on the motions of nuclear spins were successful in explaining the dipolar broadening of the NMR signal in solids and the motional narrowing in liquids [2]. With the discovery of chemical shifts and spin-spin couplings another type of dynamical process affect ing the NMR line shape became apparent, the chemical exchange. As a consequence, dynamical NMR studies split into two groups differing not only in the dynamical topics but also in the method of investigation: physical studies of the motion of spins in liquids and solids by measurement of the relaxation times of single resonances and, on the other hand, chemical studies based on band shape analysis of NMR spectra recorded under steady state conditions. The two fields of research lost some of their basic differences with the development of the Fourier transform NMR method [3], which allows the measurement of relaxation times of different resonances at the same time, i. e. the study of differential motional behavior of different parts of mole cules, thus providing a new tool in conformational analyses. For example, informa tion can be obtained by this method on the relative importance of overall motions and internal motions [4].

Biomolecular NMR Spectroscopy

Biomolecular NMR Spectroscopy PDF Author: Andrew J. Dingley
Publisher: IOS Press
ISBN: 1607506947
Category : Medical
Languages : en
Pages : 488

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Book Description
Nuclear Magnetic Resonance (NMR) spectroscopy is the most powerful technique for characterization of biomolecular structures at atomic resolution in the solution state. This timely book, entitled "Biomolecular NMR Spectroscopy," focuses on the latest state-of-the-art NMR techniques for characterization of biological macromolecules in the solid and solution state. The editors, Dr. Andrew Dingley (University of Auckland, New Zealand) and Dr. Steven Pascal (Massey University, New Zealand) have organized the book into four sections, covering the following topics: sample preparation, structure and dynamics of proteins, structure and dynamics of nucleic acids and protein-nucleic acid complexes, and rapid and hybrid techniques--

Experimental Approaches of NMR Spectroscopy

Experimental Approaches of NMR Spectroscopy PDF Author: The Nuclear Magnetic Resonance Society of Japan
Publisher: Springer
ISBN: 9811059667
Category : Science
Languages : en
Pages : 634

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Book Description
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.

Gas Phase NMR

Gas Phase NMR PDF Author: Karol Jackowski
Publisher: Royal Society of Chemistry
ISBN: 1782623817
Category : Medical
Languages : en
Pages : 419

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Book Description
This book covers the recent NMR studies with the application of gaseous molecules. Among the comprehensively discussed aspects of the area it includes in particular: new multinuclear experiments that deliver spectral parameters of isolated molecules and provide the most accurate values of nuclear magnetic shielding, isotropic spin–spin coupling and relaxation times; advanced, precise and correct theoretical descriptions of spectral parameters of molecules as well as the application of gas-phase NMR measurements to chemical analysis and medicine. The progress of research in these fields is enormous and has rapidly changed our knowledge and understanding of molecular parameters in NMR spectroscopy. For example, accurate studies of the shielding for isolated molecules allow the exact determination of nuclear magnetic dipole moments, the calculated values of spectral parameters can be verified by precise gas-phase NMR measurements, and the application of hyperpolarized noble gases provides excellent MRI pictures of lungs. Aimed at graduates and researchers in spectroscopy, analytical chemistry and those researching the applications of NMR in medicine, this book presents the connections between sophisticated experiments, the theory of magnetic parameters and the exploration of new methods in practice.

NMR Spectroscopy in Organic Chemistry

NMR Spectroscopy in Organic Chemistry PDF Author: B. I. Ionin
Publisher: Springer Science & Business Media
ISBN: 1468417851
Category : Science
Languages : en
Pages : 396

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Book Description
In recent years high-resolution nuclear magnetic resonance spec troscopy has found very wide application in organie chemistry in structural and physicochemical investigations and. also in the study of the characteristics of organic compounds which are re lated to the distribution of the electron cloud in the molecules. The vigorous development of this method, which may really be re garded as an independent branch of science, is the result of ex tensive progress in NMR technology, the refinement of its theory, and the accumulation of large amounts of experimental material, which has been correlated by empiricallaws and principles. The literature directly concerned with the NMR method and its applica tion has now grown to such an extent that a complete review of it is practically impossible. Therefore the authors have limited themselves to an examination of only the most important, funda mental, and general investigations. The book consists of six chapters. In the first chapter we have attempted to present the fundamentals of the NMR method in such a way that the reader with little knowledge of the subject will be able to use the method in practical work for investigating simple compounds and solving simple problems. The three subsequent chapters give a deeper analysis of the method, while the last two chapters and the appendix illustrate the various applications of NMR spectroscopy in organic chemistry.

Spectroscopy, Luminescence and Radiation Centers in Minerals

Spectroscopy, Luminescence and Radiation Centers in Minerals PDF Author: A.S. Marfunin
Publisher: Springer Science & Business Media
ISBN: 3642671128
Category : Science
Languages : en
Pages : 364

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Book Description
The development of mineralogy, the evolutionary changes in compre hending the mineral substance of the earth are closely associated with the progress of research methods. Over a space of more than two and half centuries, from the goniometry of the mineral crystals to microscopic petrography and optical mineralogy, to crystal structure determinations, electron micros copy and electron diffraction and finally investigations into their electri cal, magnetic and mechanical properties, all this has led to the formation of the existing system of mineralogy, its notions, theories and to a proper description of minerals. However, no matter how great the variety of methods employed in mineralogy, they all come to a few aspects of substance characteristics. These are methods of determining the composition, structure and proper ties of the minerals. Thus the X-ray micro analyzer, the atom-absorption, neutron-activation, chromatographic and other analyses open up new opportunities for determining nothing else but the elementary com position of minerals.