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Nuclear magnetic relaxation dispersion NMRD

The information content of nuclear longitudinal relaxation measurements in both paramagnetic and diamagnetic systems can be greatly increased by performing such measurements as a function of the magnetic field. For paramagnetic species, the reason is apparent from the functional form of the equations discussed in Chapter 3 and from the relevant experimental data, reported in Chapter 5. The field dependence of a relaxation rate is called relaxation dispersion, and is abbreviated as NMRD. In principle, NMRD would be helpful for any chemical system, but practical limitations, as will be shown, restrict its use, with a few exceptions, to water protons. [Pg.324]


In this connection, attention should be paid to an unusual NMR technique called nuclear magnetic relaxation dispersion (NMRD). In contrast with NMR spectroscopy, the NMRD signal arises from the nuclei of the abundant solvent molecules and not from the dissolved substances. The relaxation properties of the solvent molecules are profoundly modified if the solvent contains paramagnetic particles (see a review by Desreux 2005). A solvent molecule sails in the vicinity of an ion-radical and finds itself in the local magnetic field of this paramagnetic particle. Then, induced magnetism of the solvent molecule dissipates in the solvent bulk. This kind of relaxation seems to be registered by NMR. NMRD is applicable to studies on ion-radical solvation/desolvation, ion-pair dynamics, kinetics of ion-radical accumulation/consumption, and so on. [Pg.234]

The dependence of T (B) on the field B was soon nicknamed as the Ti dispersion curve or, more recently, as the Nuclear Magnetic Relaxation Dispersion (NMRD) profile. The first experimental curve of this type (Pig. 1) was published in 1950 by Ramsey and Pound (15,16). [Pg.406]

One effect of this rapid rotational motion is the loss of relaxivity at clinical frequencies. Figure 1 shows a Nuclear Magnetic Relaxation Dispersion (NMRD)... [Pg.203]

Nuclear Magnetic Relaxation Dispersion (NMRD). The Koenig Relaxometer Relaxivity as a function of field/frequency through analysis by simulation models r, q, rR, tm, ts for inner sphere, second sphere, and outer sphere water interactions. Also equilibrium constants for BPCA-protein and BPCA-cell interactions. [Pg.217]

Relaxation Measurements. Measurements of the magnetic fieldz dependence of the solvent water proton relaxation rate (T] l), i.e., nuclear magnetic relaxation dispersion (NMRD), were made by the field cycling method previously described (9,10). [Pg.28]

A methodology for structural studies of the first and second coordination shells in [Cr(OH2)6]3+ and related complexes in aqueous solutions, based on multiple-scattering modeling of XAFS spectra, has been developed by Munoz-Paez and co-workers.523-525 Another technique, recently applied to studying of inner- and outer-sphere H20 coordination in [Cr(OH2)6]3+, is H nuclear magnetic relaxation dispersion (NMRD).526 Applications of different instrumental methods led to consistent results, indicating the presence of 13 1 H20 molecules with an average Cr "0 distance of 4.02 A in the second coordination shell of [Cr(OH2)6]3+ in aqueous solutions.9... [Pg.348]

In addition, these anion-binding studies have been supported by optical titrations and by nuclear magnetic relaxation dispersion (NMRD) measurements. An example is presented of cyanide-treated erythrocuprein (Fig. 16). [Pg.21]

More recent nuclear magnetic relaxation dispersion (NMRD) studies involving water oxygen-17 find a much shorter residence time, in the range 10-50 ps [7]. These results are in better agreement with recent studies that seemed to rule out the existence of slower dynamics. [Pg.127]

Figure 3. Nuclear magnetic relaxation dispersion (NMRD) of MS-325 in phosphate-buffered saline (O) or in HSA solution ( ). Binding to HSA increases the correlation time, increases relaxivity, and alters the field dependence on relaxivity. Figure 3. Nuclear magnetic relaxation dispersion (NMRD) of MS-325 in phosphate-buffered saline (O) or in HSA solution ( ). Binding to HSA increases the correlation time, increases relaxivity, and alters the field dependence on relaxivity.
Measurements of spin-lattice relaxation rate as a function of the magnetic field/resonance frequency are commonly referred to as nuclear magnetic relaxation dispersion, NMRD. Measurements of this kind, when performed over a broad range, are an invaluable source of information on frequency-resolved molecular motions in complex biological or colloidal systems. Several years ago, Halle proposed a theory for relaxation of quadrupolar spins in dynamically heterogeneous systems... [Pg.258]


See other pages where Nuclear magnetic relaxation dispersion NMRD is mentioned: [Pg.277]    [Pg.163]    [Pg.47]    [Pg.105]    [Pg.93]    [Pg.144]    [Pg.324]    [Pg.325]    [Pg.327]    [Pg.90]    [Pg.201]    [Pg.217]    [Pg.263]    [Pg.265]    [Pg.84]    [Pg.90]    [Pg.201]    [Pg.217]    [Pg.159]    [Pg.63]    [Pg.108]    [Pg.230]    [Pg.231]    [Pg.529]    [Pg.236]    [Pg.584]    [Pg.146]    [Pg.629]   
See also in sourсe #XX -- [ Pg.263 , Pg.265 , Pg.270 ]

See also in sourсe #XX -- [ Pg.63 , Pg.64 ]

See also in sourсe #XX -- [ Pg.108 ]




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Magnetic relaxation dispersion:

Magnetization relaxation

Nuclear magnetic relaxation

Nuclear magnetic relaxation dispersion

Nuclear magnetic relaxation dispersion NMRD) profile

Nuclear relaxation

Relaxation dispersion

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