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Nmr Basic Principles And Progress Nmr Grundlagen Und Fortschritte
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Book Synopsis NMR Basic Principles and Progress / NMR Grundlagen und Fortschritte by : P. Diehl
Download or read book NMR Basic Principles and Progress / NMR Grundlagen und Fortschritte written by P. Diehl and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear magnetic resonance spectroscopy, which has evolved only within the last 20 years, has become one of the very important tools in chemistry and physics. The literature on its theory and application has grown immensely and a comprehensive and adequate treatment of all branches by one author, or even by several, becomes increasingly difficult. This series is planned to present articles written by experts working in various fields of nuclear magnetic resonance spectroscopy, and will contain review articles as well as progress reports and original work. Its main aim, however, is to fill a gap, existing in literature, by publishing articles written by specialists, which take the reader from the introductory stage to the latest development in the field. The editors are grateful to the authors for the time and effort spent in writing the articles, and for their invaluable cooperation. The Editors Contents c. W. Hilbers and C. MacLean NMR of Molecules Oriented in Electric Fields.
Book Synopsis NMR Basic Principles and Progress. Grundlagen und Fortschritte by : P. Diehl
Download or read book NMR Basic Principles and Progress. Grundlagen und Fortschritte written by P. Diehl and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear magnetic resonance spectroscopy, which has evolved only within the last 20 years, has become one of the very important tools in chemistry and physics. The literature on its theory and application has grown immensely and a comprehensive and adequate treatment of all branches by one author, or even by several, becomes increasingly difficult. This series is planned to present articles written by experts working in various fields of nuclear magnetic resonance spectroscopy, and will contain review articles as well as progress reports and original work, its main aim, however, is to fill a gap, existing in literature, by publishing articles written by specialists, which take the reader from the introductory stage to the latest development in the field. The editors are grateful to the authors for the time and effort spent in writing the articles, and for their invaluable cooperation. The Editors Contents P. Diehl and C. L. Khetrapal NMR Studies of Molecules Oriented in the Nematic Phase of Liquid Crystais......................................................... 1 R. G. Jones The Use of Symmetry in Nuclear Magnetic Resonance................. 97 NMR Studies of Molecules Oriented in the Nematic Phase of Liquid Crystals P. DIEHL and C. L. KHETRAPAL * Department of Physics, University of Basel, Switzerland Contents 1. Introduction . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Liquid Crystals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 . . . . . . . . . . . . . . 2.1. Classification of Liquid Crystal Phases . . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Theories of the Liquid Crystalline State . . . . . . . . . . . . . . . . . . . . . . 5 2.3. Nematic Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Experimental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1 4. Basic Theory (for I = I ). . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . 7 . .
Book Synopsis Solid-State NMR I Methods by : B. Blümich
Download or read book Solid-State NMR I Methods written by B. Blümich and published by Springer. This book was released on 1993-12-21 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis NMR Basic Principles and Progress. Grundlagen und Fortschritte by : P. Diehl
Download or read book NMR Basic Principles and Progress. Grundlagen und Fortschritte written by P. Diehl and published by Springer. This book was released on 1969 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear magnetic resonance spectroscopy, which has evolved only within the last 20 years, has become one of the very important tools in chemistry and physics. The literature on its theory and application has grown immensely and a comprehensive and adequate treatment of all branches by one author, or even by several, becomes increasingly difficult. This series is planned to present articles written by experts working in various fields of nuclear magnetic resonance spectroscopy, and will contain review articles as well as progress reports and original work, its main aim, however, is to fill a gap, existing in literature, by publishing articles written by specialists, which take the reader from the introductory stage to the latest development in the field. The editors are grateful to the authors for the time and effort spent in writing the articles, and for their invaluable cooperation. The Editors Contents P. Diehl and C. L. Khetrapal NMR Studies of Molecules Oriented in the Nematic Phase of Liquid Crystais......................................................... 1 R. G. Jones The Use of Symmetry in Nuclear Magnetic Resonance................. 97 NMR Studies of Molecules Oriented in the Nematic Phase of Liquid Crystals P. DIEHL and C. L. KHETRAPAL * Department of Physics, University of Basel, Switzerland Contents 1. Introduction . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Liquid Crystals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 . . . . . . . . . . . . . . 2.1. Classification of Liquid Crystal Phases . . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Theories of the Liquid Crystalline State . . . . . . . . . . . . . . . . . . . . . . 5 2.3. Nematic Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Experimental . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1 4. Basic Theory (for I = I ). . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . 7 . .
Book Synopsis Chlorine, Bromine and Iodine NMR by : B. Lindman
Download or read book Chlorine, Bromine and Iodine NMR written by B. Lindman and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing interest in NMR spectroscopy of what in some confer ences in this field is commonly termed "other nuclei" is unmistakable. Chemists and biologists who employ NMR spectroscopy to study their problems have, however, been somewhat reluctant to study nuclei with electric quadrupole moments. These nuclei frequently give rise to broad NMR signals, sometimes too broad to be detectable with ordinary high resolution NMR spectrometers. Spectrometers that could cope with broad NMR signals of low intensity, "wide-line" spectrometers, have been available since the mid 1950:s but it appears that most of these instruments ended up in physical laboratories where the research was primarily directed towards solid state problems. The study of quadrupolar nuclei can provide unique and very valuable information on a variety of physico-chemical and biological systems. For one thing the relaxation of quadrupolar nuclei is in many ways easier to interpret than the relaxation of non-quadrupolar nuclei, since the former is in many cases caused by purely intramolecular interactions modulated by the molecular motion. Studies of quadrupolar relaxation have therefore furnished important information about molec ular reorientation and association in liquids and have played - and will certainly play for many years - an important role in testing new theoretical models of molecular motion in liquids.
Book Synopsis Computer Assistance in the Analysis of High-Resolution NMR Spectra by : P. Diehl
Download or read book Computer Assistance in the Analysis of High-Resolution NMR Spectra written by P. Diehl and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear magnetic resonance spectroscopy, which has evolved only within the last 20 years, has become one of the very important tools in chemistry and physics. The literature on its theory and application has grown immensely and a comprehensive and adequate treatment ofall branches by one author, or even by several, becomes increasingly difficult. by experts workinginvarious This seriesis planned to present articles written fields of nuclear magnetic resonance spectroscopy, and will contain review articles as well as progress reports and original work. Its main aim, however, is to fill a gap, existing in literature, by publishing articles written by specialists, which take the reader from the introductory stage to the latest development in the field. The editors are grateful to the authors for the time and effort spent in writing the articles, and for their invaluable cooperation. The Editors Computer Assistance in the Analysis of High-Resolution NMR Spectra P. DIEHL and H. KELLERHALS Departmentof Physics, University ofBasle, Switzerland E. LUSTIG Food and Drug Administration, Washington, D.C., U.S.A.
Book Synopsis NMR Crystallography by : Robin K. Harris
Download or read book NMR Crystallography written by Robin K. Harris and published by John Wiley & Sons. This book was released on 2012-12-19 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: The content of this volume has been added to eMagRes (formerly Encyclopedia of Magnetic Resonance) - the ultimate online resource for NMR and MRI. The term "NMR Crystallography" has only recently come into common usage, and even now causes raised eyebrows within some parts of the diffraction community. The power of solid-state NMR to give crystallographic information has considerably increased since the CPMAS suite of techniques was introduced in 1976. In the first years of the 21st century, the ability of NMR to provide information to support and facilitate the analysis of single-crystal and powder diffraction patterns has become widely accepted. Indeed, NMR can now be used to refine diffraction results and, in favorable cases, to solve crystal structures with minimal (or even no) diffraction data. The increasing ability to relate chemical shifts (including the tensor components) to the crystallographic location of relevant atoms in the unit cell via computational methods has added significantly to the practice of NMR crystallography. Diffraction experts will increasingly welcome NMR as an allied technique in their structural analyses. Indeed, it may be that in the future crystal structures will be determined by simultaneously fitting diffraction patterns and NMR spectra. This Handbook is organised into six sections. The first contains an overview and some articles on fundamental NMR topics, followed by a section concentrating on chemical shifts, and one on coupling interactions. The fourth section contains articles describing how NMR results relate to fundamental crystallography concepts and to diffraction methods. The fifth section concerns specific aspects of structure, such as hydrogen bonding. Finally, four articles in the sixth section give applications of NMR crystallography to structural biology, organic & pharmaceutical chemistry, inorganic & materials chemistry, and geochemistry. About EMR Handbooks / eMagRes Handbooks The Encyclopedia of Magnetic Resonance (up to 2012) and eMagRes (from 2013 onward) publish 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 / eMagRes Handbooks on specific areas of NMR and MRI. The chapters of each of these handbooks will comprise a carefully chosen selection of articles from eMagRes. In consultation with the eMagRes Editorial Board, the EMR Handbooks / eMagRes 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 eMagRes at your fingertips! Visit: www.wileyonlinelibrary.com/ref/eMagRes View other eMagRes publications here
Book Synopsis Solid State NMR Studies of Biopolymers by : Anne E. McDermott
Download or read book Solid State NMR Studies of Biopolymers written by Anne E. McDermott and published by John Wiley & Sons. This book was released on 2012-12-19 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt: The content of this volume has been added to eMagRes (formerly Encyclopedia of Magnetic Resonance) - the ultimate online resource for NMR and MRI. The field of solid state NMR of biological samples [ssNMR] has blossomed in the past 5-10 years, and a cohesive overview of the technology is needed for new practitioners in industry and academia. This title provides an overview of Solid State NMR methods for studying structure dynamics and ligand-binding in biopolymers, and offers an overview of RF pulse sequences for various applications, including not only a systematic catalog but also a discussion of theoretical tools for analysis of pulse sequences. Practical examples of biochemical applications are included, along with a detailed discussion of the many aspects of sample preparation and handling that make spectroscopy on solid proteins successful. About EMR Handbooks / eMagRes Handbooks The Encyclopedia of Magnetic Resonance (up to 2012) and eMagRes (from 2013 onward) publish 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 / eMagRes Handbooks on specific areas of NMR and MRI. The chapters of each of these handbooks will comprise a carefully chosen selection of articles from eMagRes. In consultation with the eMagRes Editorial Board, the EMR Handbooks / eMagRes 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 eMagRes at your fingertips! Visit: www.wileyonlinelibrary.com/ref/eMagRes View other eMagRes publications here
Book Synopsis Nuclear Magnetic Resonance Studies in Lyotropic Liquid Crystals by : CL Khetrapal
Download or read book Nuclear Magnetic Resonance Studies in Lyotropic Liquid Crystals written by CL Khetrapal and published by Springer Science & Business Media. This book was released on 2013-03-13 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: 1. Lyotropic Liquid Crystals The class of compounds known as thermotropic liquid crystals has been widely utilized in basic research and industry during recent years. The properties of these materials are such that on heating from the solid to the isotropic liquid state, phase transitions occur with the formation of one or more intermediate anisotropic liquids. The unique and sometimes startling properties of these liquid crystals are the properties of pure compounds. However, there exists a second class of substances known as lyotropic liquid crystals which obtain their anisotropic properties from the mixing of two or more components. One of the components is amphiphilic, containing a polar head group (generally ionic or zwitterionic) attached to one or more long-chain hydrocarbons; the second component is usually water. Lyotropic liquid crystals occur abundantly in nature, particularly in all living systems. As a consequence, a bright future seems assured for studies on such systems. Even now, many of the properties of these systems are poorly understood. It is the purpose of this review to consolidate the results obtained from nuclear magnetic resonance studies of such systems and to provide a coherent picture of the field. Probably the most familiar example of a lyotropic liquid crystal is soap in water. A common soap is sodium dodecylsulphate where an ionic group (sulphate) is attached to a hydrocarbon chain containing twelve carbons.
Book Synopsis High Resolution NMR Spectroscopy in Solids by : M. Mehring
Download or read book High Resolution NMR Spectroscopy in Solids written by M. Mehring and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis 15N-NMR Spectroscopy by : G.J. Martin
Download or read book 15N-NMR Spectroscopy written by G.J. Martin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: After the proton and carbon, nitrogen is, with oxygen, the most impor tant atom in organic and especially bioorganic molecules. However, the development of nitrogen spectroscopy is indeed very recent. This is due to the fact that nitrogen-14, which is the naturally abundant iso tope, suffers, for structural studies, from the disadvantages inherent in nuclei with a quadrupolar moment (Table 1.1). Actually, indirect 15N measurements were reported in the early days of double resonance spectroscopy and the first direct detection of 15N resonance signals at the natural abundance level was realized in 1964 (R 17) at 4.33 MHz 1 (~ 1T) using a 15 mm o.d. cell in the field sweep mode (~ 0.16 min- ). Signal-to-noise ratios only of 3-4 were obtained for neat liquids and this low sensitivity of the 15N resonance still remains the main dis advantage for 15 spectroscopy (Table 1.1). However, nitrogen-15 has, N probably more than any other nucleus, benefited from the advances of NMR technology, i.e. Fourier transformation, multinuclear facilities, wide-bore super conducting solenoids, and, with the new generation of spectrometers, 15N-NMR is entering the field of routine investigation. Nevertheless, in spite of these spectacular improvements, obtaining 15N spectra of diluted species or large biochemical molecules is often not very easy and a good knowledge of the relaxation properties pecu liar to 15N may be necessary in order to adjust the pulse sequences and the decoupler duty cycle correctly (Section 2).
Book Synopsis 31P and 13C NMR of Transition Metal Phosphine Complexes by : Paul S. Pregosin
Download or read book 31P and 13C NMR of Transition Metal Phosphine Complexes written by Paul S. Pregosin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Book Synopsis Ab Initio Calculations by : Petr Carsky
Download or read book Ab Initio Calculations written by Petr Carsky and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Until recently quantum chemical ab initio calculations were re stricted to atoms and very small molecules. As late as in 1960 Allen l and Karo stated : "Almost all of our ab initio experience derives from diatomic LCAO calculations ••• N and we have found in the litera ture "approximately eighty calculations, three-fourths of which are for diatomic molecules ••• There are approximately twenty ab initio calculations for molecules with more than two atoms, but there is a decided dividing line between the existing diatomic and polyatomic wave functions. Confidence in the satisfactory evaluation of the many -center two-electron integrals is very much less than for the diatom ic case". Among the noted twenty calculations, SiH was the largest 4 molecule treated. In most cases a minimal basis set was used and the many-center two-electron integrals were calculated in an approximate way. Under these circumstances the ab initio calculations could hard ly provide useful chemical information. It is therefore no wonder that the dominating role in the field of chemical applications was played by semiempirical and empirical methods. The situation changed essentially in the next decade. The problem of many-center integrals was solved, efficient and sophisticated computer programs were devel oped, basis sets suitable for a given type of problem were suggested, and, meanwhile, a considerable amount of results has been accumulated which serve as a valuable comparative material. The progress was of course inseparable from the development and availability of computers.
Book Synopsis Analysis of NMR Spectra by : R. A. Hoffman
Download or read book Analysis of NMR Spectra written by R. A. Hoffman and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nuclear magnetic resonance spectroscopy, which has evolved only within the last 20 years, has become one of the very important tools in chemistry and physics. The literature on its theory and application has grown immensely and a comprehensive and adequate treatment of all branches by one author, or even by several, becomes increasingly difficult. This series is planned to present articles written by experts working in various fields of nuclear magnetic resonance spectroscopy, and will contain review articles as well as progress reports and original work. Its main aim, however, is to fill a gap, existing in literature, by publishing articles written by specialists, which take the reader from the introductory stage to the latest development in the field. The editors are grateful to the authors for the time and effort spent in writing the articles, and for their invaluable cooperation. The Editors Analysis of NMR Spectra A Guide for Chemists R. A. HOFFMAN t S. FORSEN Division of Physical Chemistry, Chemical Center, Lund Institute of Technology, Lund, Sweden B. GESTBLOM Institute of Physics, University of Uppsala, Sweden Contents I. Principles of NMR Spectroscopy 4 1. 1. The Magnetic Resonance Phenomenon 4 a) Nuclear Moments. . . . . . . . 4 b) Magnetic Spin States and Energy Levels 5 c) The Magnetic Resonance Condition. 7 d) The Larmor Precession. . 7 e) Experimental Aspects . . . . 8 1. 2. Chemical Shifts . . . . . . . . 9 a) The Screening Constant 11. . . 9 b) Chemical Shift Scales (11 and r) 10 1. 3. Spin Coupling Constants 12 1. 4. Intensities. . . . . . . .
Download or read book Oxygen-17 and Silicon-29 written by and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although it was shown very early [1] that the isotope 29Si is very valuable for NMR research, severe technical difficulties had to be overcome before silicon spectra could be recorded. This was due to the low sensitivity of the isotope resulting from its low gyro magnetic ratio, its low abundance and the rather long relaxation times. The introduction of the Fourier-Transform-Technique (FT-NMR) helped to surmount most of these problems, with the result, that more and more papers concerning silicon NMR appear. Thus, it seems now that most of the salient features of 29Si-NMR are known today. Some resume of the state of the art of 29Si_NMR have been reported [1-4]. Although the theory of 29Si-NMR is not yet understood beyond the basic features, it promises to be of value mainly for two reasons: 1. Silicon is strategically located in the Periodic Table of the elements between the elements carbon, aluminum and phosphorus. For an unified theory of chemical shifts and coupling constants of the heavier elements silicon NMR values will be important. 2. The normal coordination number of silicon is four. If the current view of the chemical shifts of the heavier elements is correct, then the paramagnetic part is dominant for the measured shift data. Two of the parameters used for the calcu lation of the paramagnetic part are bond orders and angles. Bond angles are rare ly determined experimentally with high precision.
Book Synopsis Chemically Induced Dynamic Nuclear and Electron Polarizations-CIDNP and CIDEP by : C. Richard
Download or read book Chemically Induced Dynamic Nuclear and Electron Polarizations-CIDNP and CIDEP written by C. Richard and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anomalous electron-spin state populations in the Electron Paramagnetic Re sonance (EPR) spectra of radicals formed during radio lysis experiments were observed in 1963 by FESSENDEN and SCHULER [170a]. This phenomenon did not receive much attention at the time. In 1967, BARGON, FISCHER, and JOHNSEN [5] and independently WARD and LAWLER [7,8] reported a similar phenomenon for Nuclear Magnetic Resonance (NMR) spectra taken during radical reactions: emission or enhanced absorption, or both. The earliest attempts to explain this new NMR phenomenon treated these effects in a way similar to that of Dynamic Nuclear Polarization (DNP) or the Overhauser effect. Although the polarization has a completely different origin, DNP gave its name to this effect: Chemically Induced Dynamic Nuclear Polariza tion (CIDNP). [The name Chemically Induced Dynamic Electron Polarization (CIDEP) was introduced later by analogy with CIDNP]. After the initial publica tions, all the new data demonstrated that the first theory could not be correct. In 1969, a new theory was proposed by CLOSS [18] and independently by KAPTEIN and OOSTERHOFF [23] and called the radical-pair theory. This mechanism was proposed to account for the observations of polarization in both NMR and EPR. The radical-pair theory is based on weak interactions in a pair of radicals: the strength of interaction between the electronic states of the radicals depends in particular on the nuclear-spin states.
Book Synopsis Introductory Essays by : M. M. Pintar
Download or read book Introductory Essays written by M. M. Pintar and published by Springer Science & Business Media. This book was released on 2013-03-12 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: This set of essays was given as lectures at the 4th Waterloo International Summer School on Nuclear Magnetic Resonance held in June 1975 at the University of Water loo. The school was sponsored by the National Research Council of Canada and by the Canadian Association of Physicists. These Contributions are introductory and were not intended to be review papers. For valuable help, I would like to thank R. S. Hallsworth, D. W. Nicoll, and R. T. Thompson. M.M.Pintar Table of Contents A Guide to Relaxation Theory. By A. G. Redfield .................... 1 Thermodynamics of Spin Systems in Solids. An Elementary Introduction. By J. Jeener. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 . . . . . . . . . . . . Coherent Averaging and Double Resonance in Solids. By J. S. Waugh. . . . . .. . 23 Macroscopic Dipole Coherence Phenomena. By. E. L. Hahn . . . . . . . . . .. . . 31 . Nuclear Spins and Non Resonant Electromagnetic Phenomena. By G. J. Bene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 45 . . . . . . . . . Nuclear Spin Relaxation in Molecular Hydrogen. By F. R. McCourt. . . . . . .. . 55 Longitudinal Nuclear Spin Relaxation Time Measurements in Molecular Gases. By R. L. Armstrong . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 71 . . . . . . . Spin-Lattice Relaxation in Nematic Liquid Crystals Via the Modulation of the Intramolecular Dipolar Interactions by Order Fluctuations. By R. Blinc . . .. 97 NMR Studies of Molecular Tunnelling. By S. Clough . . . . . . . . . . . . .. . . . 113 . . Effect of Molecular Tunnelling on NMR Absorption and Relaxation in Solids. By M. M. Pintar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . 125 . . . . . . . . . .
