Nuclear magnetic resonance dipole interaction

Nuclear magnetic resonance (NMR) has been used to determine electrical properties in a conventional setup [23], but recently, applied electric fields have been incorporated for the determination of properties [24, 25]. Polar liquids and solutions of polar molecules align when a strong electric field (about 300 kV/cm) is applied. The anisotropic spin interactions essentially modify the NMR spectrum, and determinations of the lowest order dipole polarizability can be made. To low order, the interaction energy may be taken to be... 

Abstract Modern solid state nuclear magnetic resonance presents new powerful opportunities for the elucidation of medium range order in glasses in the sub-nanometer region. In contrast to standard chemical shift spectroscopy, the strategy presented here is based on the precise measurement and quantitative analysis of internuclear magnetic dipole-dipole interactions, which can be related to distance information in a straightforward manner. The... 

It can now be predicted with confidence that machine calculations will lead gradually toward a really fundamental quantitative understanding of the rules of valence and the exceptions to these toward a real understanding of the dimensions and detailed structures, force constants, dipole moments, ionization potentitils, and other properties of stable molecules and equally unstable radicals, anions, and cations, and chemical reaction intermediates toward a basic understanding of activated states in chemical reactions, and of triplet and other excited states which are important in combustion and explosion processes and in photochemistry and in radiation chemistry and also of intermolecular forces further, of the structure and stability of metals and other solids of those parts of molecular wave functions which are important in nuclear magnetic resonance, nuclear quadrupole coupling, and other interaction involving electrons and nuclei and of very many other aspects of the structure of matter which are now understood only qualitatively or semi-empirically. 

We define the hydration number as the average number of water molecules in the first sphere about the metal ion. The residence time of these molecules is determined generally by the nature of the bonding to the metal ion. For the f-element cations, ion-dipole interactions result in fast exchange between the hydration layer and the bulk solvent. The techniques for studying the nature (number and/or structure) of the hydration shell can be classified as either direct or indirect methods. The direct methods include X-ray and neutron diffraction, luminescence and NMR (nuclear magnetic resonance) relaxation measurements. The indirect methods involve compressibility, NMR exchange and absorption spectroscopy measurements. 

Nuclear magnetic resonance has been used extensively in the last decade to study the structure and dynamics of model and biological membranes. However, the complexity of these systems, which should manifest itself in a corresponding richness of their NMR snectra, has in most cases not been observed because of the substantial breadth of the NMR lines. It is now understood that this breadth is due nrimarily to residual chemical shift anisotropy and dipole-dipole interactions. 

---