Developments, in NMR

Recent Developments in NMR Spectroscopy Soft Two-Dimensional Experiment... 

A major limitation in using protein NMR spectroscopy in drug discovery has been the molecular weight limitation imposed by nuclear spin relaxation (line broadening) and increased spectral complexity associated with macromolecules larger than 35 kDa [5]. The most recent developments in NMR spectroscopy aimed at overcoming these problems will be briefly reviewed in Sect. 21.2. 

Recording the NMR-spectra is a tedious and time consuming process. However, with the advent of recent developments in NMR-spectroscopy it is quite possible to eliminate some of these short comings adequately. They are ... 

In actual practice, the latter mode is technically more demanding and affords results that are much higher in sensitivity. Recent developments in NMR-spectrometer hardware and technique have made this more-sensitive-mode of operation, termed as inverse-detection , rather readily applicable to modem analysis. 

This book is part of the Analytical Spectroscopy Library series, and is devoted to high-resolution NMR, specifically applications in the structure elucidation of organic molecules of moderate molecular weight. The book contains 16 loosely connected chapters written by some of today s most accomplished NMR scientists. Much emphasis has been given to the latest developments in NMR, in particular to selective pulses and pulsed field gradients. 

This pulsed wave process provides simultaneous information on all the frequencies present. The generalisation of this process, which can be computerised and allows the study of less sensitive nuclei such as 13C, has led to major developments in NMR. 

ERNST. RICHARD R. (I933-). A native of Switzerland who won the Nobel prize in chemistry in 1991 for important methodological developments in NMR spectroscopy. He invented Fourier-transform NMR lET-NMR). which multiplied sensitivity It) to 100 times compared to dispersive instruments. He also devised two-dimensional NMR techniques, increasing resolution and enabling structure determinations of biologically important macromolecules. Ernst received his Pli.D from the Federal Technical Institute (ETH) in Zurich. Switzerland... 

One of the most startling developments in nmr spectroscopy since its inception has been the discovery of chemically induced dynamic nuclear polarization or CIDNP. An especially dramatic example is provided by irradiation of 3,3-dimethyl-2-butanone with ultraviolet light. 

NMR spectroscopy has proven to be an invaluable tool in structure determination of hydrogenated fullerenes ever since the first synthesis of C60H36 (Haufler et al. 1990) and the first structure determination by NMR was reported for C60H2 by Henderson and Cahill in 1993 (Henderson and Cahill 1993). Today, a multitude of both one- and two-dimensional NMR experiments are available for this purpose. Recent developments in NMR technology with higher magnetic field strengths and cryoprobes have dramatically increased the sensitivity and improved the usefulness of NMR in this field even further. 

Further developments in NMR were presented in Sydney (1980) on high-resolution NMR by J. F. G. Vliegenthart, and on two-dimensional NMR by L. D. Hall. More applications of conformational analysis were discussed by K. Bock (Vancouver 1982) on the conformations of oligosaccharides, by H. J. Jennings (Utrecht 1984), on the conformations of some polysaccharides, by I. Tvaroska (Stockholm 1988), on computational methods for determining conformations, and by Y. Kishi (Paris 1992) on the conformations of C-glycosyl compounds. 

Luckily due to recent developments in NMR probe design, there is now a third option, which can, to some extent, be used to address key questions as to the... 

This section highlights the typical applications of 13C- and 1H-detected INADEQUATE and details a selection of examples from different areas of chemistry. These include primary structure determination of small molecules, the use of partially 13C-enriched compounds in biosynthetic studies, the recent structural analysis of fullerenes and the latest development in NMR hardware that promises to advance the use of high-resolution INADEQUATE experiments for polymers. 

Hyphenated analytical and spectroscopic techniques have enhanced the ability of analysts to solve structural problems. Until the advent of recent developments in NMR, LC-MS had been the only hyphenated technique for qualitative analysis of structures on mixtures. NMR could... 

Recent developments in NMR spectroscopy, along with advances in computational techniques, have produced new approaches to the interpretation of spin-spin coupling constants extracted from biomolecules. Quantum chemical studies of useful accuracy are now becoming more routine, and are increasingly being used in conjunction with experimental data to map out the expected structural patterns for oligosaccharides, as well as other biomolecules. 

This book is written from the perspective of an NMR facility manager in an academic research laboratory and as such the topics included are naturally influenced by the areas of chemistry I encounter. The methods are chosen, however, for their wide applicability and robustness, and because, in many cases, they have already become established techniques in NMR laboratories in both academic and industrial establishments. This is not intended as a review of all recent developments in NMR techniques. Not only would this be too immense to fit within a single volume, but the majority of the methods would... 

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