Preparation of XeOF3+·Sb2F11–and XeO2F+·Sb2F11–.19F nuclear magnetic resonance and Raman spectra of XeOF3+and XeO2F+

The infrared and Raman spectra of chloryl hexafluoroarsenate have been obtained. The observed vibrations have been interpreted in terms of an ionic compound ClO2+AsF6−, where strong cation–anion interaction results in a symmetry lowering of the AsF6− ion. The compound together with chloryl fluoride produces the chloronium cation ClO2+(solv) in solution of fluorosulfuric acid. The solvolysis of FClO2 is studied by conductometry and 19F nuclear magnetic resonance (n.m.r.) in order to elucidate the observed anion–cation interaction for ClO2AsF6 more fully. 19F n.m.r. studies of FClO2 and related molecules have been used to discuss the bonding in chloronium compounds.

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Analysis by Optimized Gas Chromatography/Infrared/Nuclear Magnetic Resonance Techniques

Applied Spectroscopy ◽

10.1366/000370277774463328 ◽

1977 ◽

Vol 31 (5) ◽

pp. 456-463 ◽

Cited By ~ 6

Author(s):

Kenneth L. Gallaher ◽

Jeanette G. Grasselli

Keyword(s):

Nuclear Magnetic Resonance ◽

Gas Chromatography ◽

Magnetic Resonance ◽

Raman Spectra ◽

Vapor Phase ◽

Nmr Spectra ◽

Proton Nmr ◽

Phase Spectra ◽

Nuclear Magnetic

A method is described for obtaining infrared and proton NMR spectra of the same GC fraction from a mixture. The infrared vapor phase spectra are provided by a Norcon GC/ir instrument. Peaks of interest are then collected directly into a disposable 1.2 mm capillary for the microinsert of a Varian XL-100 probe. The versatility and power of this optimized combination are illustrated with several examples, including several where GC/MS was not specific. Raman spectra can also be obtained on the same GC fraction.

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An emerging technology: Nuclear magnetic resonance microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010706x ◽

1988 ◽

Vol 46 ◽

pp. 1000-1001

Author(s):

M.J. Hennessy ◽

E. Kwok

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Relaxation Times ◽

Basic Research ◽

Local Environment ◽

Magnetic Resonance Images ◽

Nmr Microscopy ◽

Mri Scans ◽

Temperature Relaxation ◽

Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

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Nuclear magnetic resonance microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156110 ◽

1989 ◽

Vol 47 ◽

pp. 828-829

Author(s):

Paul C. Lauterbur

Keyword(s):

Magnetic Field ◽

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Magnetic Fields ◽

Signal To Noise ◽

Field Gradients ◽

Useful Signal ◽

Magnetic Field Gradients ◽

Observation Times ◽

Nuclear Magnetic

Nuclear magnetic resonance imaging can reach microscopic resolution, as was noted many years ago, but the first serious attempt to explore the limits of the possibilities was made by Hedges. Resolution is ultimately limited under most circumstances by the signal-to-noise ratio, which is greater for small radio receiver coils, high magnetic fields and long observation times. The strongest signals in biological applications are obtained from water protons; for the usual magnetic fields used in NMR experiments (2-14 tesla), receiver coils of one to several millimeters in diameter, and observation times of a number of minutes, the volume resolution will be limited to a few hundred or thousand cubic micrometers. The proportions of voxels may be freely chosen within wide limits by varying the details of the imaging procedure. For isotropic resolution, therefore, objects of the order of (10μm) may be distinguished.Because the spatial coordinates are encoded by magnetic field gradients, the NMR resonance frequency differences, which determine the potential spatial resolution, may be made very large. As noted above, however, the corresponding volumes may become too small to give useful signal-to-noise ratios. In the presence of magnetic field gradients there will also be a loss of signal strength and resolution because molecular diffusion causes the coherence of the NMR signal to decay more rapidly than it otherwise would. This phenomenon is especially important in microscopic imaging.

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