Transition Metal Nuclear Magnetic Resonance

Transition Metal Nuclear Magnetic Resonance PDF Author: P. S. Pregosin
Publisher: Elsevier Publishing Company
ISBN:
Category : Science
Languages : en
Pages : 372

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Book Description
Transition metal NMR spectroscopy has progressed enormously in recent years. New methods, and specifically solid-state methods and new pulse sequences, have allowed access to data from nuclei with relatively low receptivities with the result that chemists have begun to consider problems previously inaccessible. Moreover, theory, and computational science in particular, now permits the calculation of not just 13 C, 15 N and other light nuclei chemical shifts, but also heavy main-group elements and transition metals. This, combined with increasing access to high field pulsed spectrometers has produced a wealth of new data on NMR of transition metals. understanding and using the nuclear magnetic resonance spectra of the metals of Groups 3-12. The reader is provided with a view on how these nuclei are currently being approached, and what information can be obtained. The authors have liberally reproduced spectra as well as correlations relating metal-NMR data to different physical characteristics of their molecules.

Transition Metal Nuclear Magnetic Resonance

Transition Metal Nuclear Magnetic Resonance PDF Author: P. S. Pregosin
Publisher: Elsevier Publishing Company
ISBN:
Category : Science
Languages : en
Pages : 372

Get Book Here

Book Description
Transition metal NMR spectroscopy has progressed enormously in recent years. New methods, and specifically solid-state methods and new pulse sequences, have allowed access to data from nuclei with relatively low receptivities with the result that chemists have begun to consider problems previously inaccessible. Moreover, theory, and computational science in particular, now permits the calculation of not just 13 C, 15 N and other light nuclei chemical shifts, but also heavy main-group elements and transition metals. This, combined with increasing access to high field pulsed spectrometers has produced a wealth of new data on NMR of transition metals. understanding and using the nuclear magnetic resonance spectra of the metals of Groups 3-12. The reader is provided with a view on how these nuclei are currently being approached, and what information can be obtained. The authors have liberally reproduced spectra as well as correlations relating metal-NMR data to different physical characteristics of their molecules.

31P and 13C NMR of Transition Metal Phosphine Complexes

31P and 13C NMR of Transition Metal Phosphine Complexes PDF Author: Paul S. Pregosin
Publisher: Springer Science & Business Media
ISBN: 3642488307
Category : Science
Languages : en
Pages : 164

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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.

The Multinuclear Approach to NMR Spectroscopy

The Multinuclear Approach to NMR Spectroscopy PDF Author: J.B. Lambert
Publisher: Springer Science & Business Media
ISBN: 9400971303
Category : Mathematics
Languages : en
Pages : 552

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Book Description
The field of nuclear magnetic resonance has experienced a number of spectacular developments during the last decade. Fourier transform methodology revolutionized signal acquisition capabilities. Superconducting magnets enhanced sensitivity and produced considerable improvement in spectral dispersion. In areas of new applicat ions, the life sciences particularly bene fited from these developments and probably saw the largest increase in usage. NMR imaging promises to offer a noninvasive alternative to X rays. High resolution is now achievable with solids, through magic angle spinning and cross polarization, so that the powers of NMR are applicable to previously intractable materials such as polymers, coal, and other geochemicals. The ease of obtaining relaxation times brought an important fourth variable, after the chemical shift, the coupling constant, and the rate constant, to the examination of structural and kinetic problems i~ all fields. Software development, particularly in the area of pulse sequences, created a host of useful tech niques, including difference decoupling and difference nuclear Overhauser effect spectra, multidimensional displays, signal enhancement (INEPT), coupling constant analysis for connectivity (INADEQUATE), and observation of specific structural classes such as only quaternary carbons. Finally, hardware development gave us access to the entire Periodic Table, to the particular advan tage of the inorganic and organometallic chemist. At the NATO Advanced Study Institute at Stirling, Scotland, the participants endeavored to examine all these advances, except imaging, from a multidisciplinary point of view.

Magnetic Properties of Layered Transition Metal Compounds

Magnetic Properties of Layered Transition Metal Compounds PDF Author: L.J. de Jongh
Publisher: Springer Science & Business Media
ISBN: 9400918607
Category : Science
Languages : en
Pages : 430

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Book Description
In the last two decades low-dimensional (low-d) physics has matured into a major branch of science. Quite generally we may define a system with restricted dimensionality d as an object that is infinite only in one or two spatial directions (d = 1 and 2). Such a definition comprises isolated single chains or layers, but also fibres and thin layers (films) of varying but finite thickness. Clearly, a multitude of physical phenomena, notably in solid state physics, fall into these categories. As examples, we may mention: • Magnetic chains or layers (thin-film technology). • Metallic films (homogeneous or heterogeneous, crystalline, amorphous or microcristalline, etc.). • I-d or 2-d conductors and superconductors. • Intercalated systems. • 2-d electron gases (electrons on helium, semiconductor interfaces). • Surface layer problems (2-d melting of monolayers of noble gases on a substrate, surface problems in general). • Superfluid films of ~He or 'He. • Polymer physics. • Organic and inorganic chain conductors, superionic conductors. • I-d or 2-d molecular crystals and liquid crystals. • I-d or 2-d ferro- and antiferro electrics.

Spectral Methods in Transition Metal Complexes

Spectral Methods in Transition Metal Complexes PDF Author: K. Sridharan
Publisher: Elsevier
ISBN: 0128096543
Category : Science
Languages : en
Pages : 201

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Book Description
Spectral Methods in Transition Metal Complexes provides a conceptual understanding on how to interpret the optical UV-vis, vibrational EPR, and NMR spectroscopy of transition metal complexes. Metal complexes have broad applications across chemistry in the areas of drug discovery, such as anticancer drugs, sensors, special materials for specific requirements, and catalysis, so a thorough knowledge in preparation and characterization of metal complexes, while niche, is critical. Accessible to both the seasoned researcher and the graduate student alike, this book provides readers with a single source of content that addresses spectral methods in transition metal complexes. - Provides readers with a single reference on metal complexes and coordination compounds - Contains more than 100 figures, tables, and illustrations to aid in the retention of key concepts - Authored by a scientist with nearly 40 years of experience in research and instruction

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.

Electron Paramagnetic Resonance of d Transition Metal Compounds

Electron Paramagnetic Resonance of d Transition Metal Compounds PDF Author: F.E. Mabbs
Publisher: Elsevier
ISBN: 1483291499
Category : Science
Languages : en
Pages : 1347

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Book Description
Electron paramagnetic resonance (epr) spectroscopy is a sensitive and versatile method of studying paramagnets, which is finding increasing use in chemistry, biochemistry, earth and materials sciences. The technique is treated both qualitatively and quantitatively, with a progressive increase in sophistication in each succeeding chapter. Following a general introductory chapter, the first half of the book deals with single unpaired electron systems and considers both metal and ligand Zeeman, hyperfine and quadrupole interactions. The simulation of these spectra is discussed, followed by the relationship between spin-Hamiltonian parameters and models of the electronic structures of paramagnets. The second half of the book treats multiple unpaired electron systems using the same philosophy. An introduction to the epr properties of cluster compounds and of extended exchanging systems is also given. There is a chapter on linewidths and lineshapes, and an extensive appendix containing much additional information. A wide-ranging library of simulated and experimental spectra is given, as well as graphical data which should aid spectrum interpretation. Each chapter contains key references and there is a substantial subject and keyword index. This book is designed to teach epr spectroscopy to students without any previous knowledge of the technique. However, it will also be extremely useful to researchers dealing with paramagnetic d transition metals.

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.

Mössbauer Spectroscopy and Transition Metal Chemistry

Mössbauer Spectroscopy and Transition Metal Chemistry PDF Author: P. Gütlich
Publisher: Springer Science & Business Media
ISBN: 3662125455
Category : Science
Languages : en
Pages : 292

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Book Description
Two decades have passed since the original discovery of recoilless nuclear gamma resonance by Rudolf Mossbauer; the spectroscopic method based on this resonance effect - referred to as Mossbauer spectroscopy - has developed into a powerful tool in solid-state research. The users are chemists, physicists, biologists, geologists, and scientists from other disciplines, and the spectrum of problems amenable to this method has become extraordinarily broad. In the present volume we have confined ourselves to applications of Mossbauer spectroscopy to the area of transition elements. We hope that the book will be useful not only to non-Mossbauer special ists with problem-Oriented activities in the chemistry and physics of transition elements, but also to those actively working in the field of Mossbauer spectroscopy on systems (compounds as well as alloys) of transition elements. The first five chapters are directed to introducing the reader who is not familiar with the technique to the principles of the recoilless nuclear resonance effect, the hyperfme interactions between nuclei and electronic properties such as electric and magnetic fields, some essential aspects about measurements, and the evaluation of Moss bauer spectra. Chapter 6 deals with the interpretation of Mossbauer parameters of iron compounds. Here we have placed emphasis on the information about the electronic structure, in correlation with quantum chemical methods, because of its importance for chemical bonding and magnetic properties.

Biological NMR Spectroscopy

Biological NMR Spectroscopy PDF Author: John L. Markley
Publisher: Oxford University Press
ISBN: 0195094689
Category : Medical
Languages : en
Pages : 375

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Book Description
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.