Resonance Data

M Vasquez, ElA Scheraga. Calculation of protein conformation by the build-up procedure. Application to bovine pancreatic trypsin inhibitor using limited simulated nuclear magnetic resonance data. J Biomol Struct Dyn 5 705-755, 1988. 

Fig. 20. A. Conformation of the Valinomycin-cation complex derived for solution using a combination of proton magnetic resonance data and conformational energy calculations. This structure agrees within tenths of an Angstrom with the crystal structure subsequently determined (100) and shown in Fig. 21. Reproduced with permission from Ref.99).

A review is given of the application of Molecular Dynamics (MD) computer simulation to complex molecular systems. Three topics are treated in particular the computation of free energy from simulations, applied to the prediction of the binding constant of an inhibitor to the enzyme dihydrofolate reductase the use of MD simulations in structural refinements based on two-dimensional high-resolution nuclear magnetic resonance data, applied to the lac repressor headpiece the simulation of a hydrated lipid bilayer in atomic detail. The latter shows a rather diffuse structure of the hydrophilic head group layer with considerable local compensation of charge density. 

Goslar, J., L. Piekara-Sady et al. (1994). ENDOR data tabulations. In Poole, C. P. and Farach, H. A. (eds.), Handbook of Electron Spin Resonance Data Sources, Computer Technology, Relaxation and ENDOR. New York AIP Press. 

Electron Spin Resonance Data for Hyperfine Interaction... 

While this generally has only small effects on the static magnetic properties, it may play a relevant role in providing a quantitative agreement with experimental resonance data, and in explaining quantum tunnelling relaxation of the magnetization at low temperature [51]. 

Because of the scarcity of electronic paramagnetic resonance data, and because of the frequent unreliability of the data from paramagnetism, boiling point elevation, spectrophotometry, and ortho-para hydrogen conversion, most published radical dissociation constants can be accepted only with reservations. An error of 50 % is not at all improbable in many cases. We are therefore not yet in a position to explain, or rather to test our explanations of, small differences in dissociation constants. Table I shows the values of K corresponding to various hexaarylethanes in benzene at 25°. Because of the order of magnitude differences in Table I, however, it is likely that some of the expected large effects, such as steric and resonance effects, exist. 

Electron spin resonance data for a representative selection of organic nitroxides 1- ... 

Selected electron spin resonance data for spin adducts of C-nitroso-compounds (see also Table l)0 ... 

As indicated in the previous discussion, Mossbauer spectroscopy provides information that when coupled with results using other structural techniques assists in determining the structure of the complex under analysis. The relationships between the various techniques are summarized in Table II. The Mossbauer chemical shift provides information about the 4 electron contribution to the bond between the metal and the ligands in a complex. Similar estimates can be obtained from the results of measurements on the fine structure in the x-ray absorption edge and nuclear magnetic resonance data. The number of unpaired electrons can be evaluated from magnetic susceptibility data, electron spin resonance, and the temperature coeflScient of the Mossbauer quadrupole splitting (Pr). 

Information concerning the symmetry of the electric field at the metal nucleus can be found from this latter parameter, AEq, which can also be measured directly by nuclear quadrupole resonance techniques. Additional information concerning the symmetry of the ligand around the metal can be deduced from x-ray, infrared, and nuclear magnetic resonance data. 

The alkali iodide isomeric shifts (13) number of iodine ion p holes calculated rupole resonance data (25) the sum of overlap integrals (11) the fractional iodine ion density computed from the isomeric shift data. Equation 7, and 8. 

The data indicate good agreement with those of the resonance data. 

Penney and Schlapp, Van Vleck and others applied these results to interpret magnetic susceptibility data of paramagnetic transition group ions in crystals. More recently, the theory has been applied with considerable success to electron magnetic resonance data 126,140,14I) and to the optical spectra 142) of paramagnetic ions in solids. 

Infrared and nuclear magnetic resonance data for the U(C5H5)3R complexes are consistent with a metal-carbon a bond, and this fact has been confirmed by the structural analysis of tricyclopentadienylphenyethynyluranium(IV) (72). The molecular geometry (Fig. 13) about the uranium is a distorted tetrahedron with... 

Obtaining resonance data on elements other than those mentioned above is not very easy and available data are therefore rather scarce. The other nuclei will be reviewed according to the method used for observing the resonance. 

Lopez-Quintela MA (2003) Synthesis of nanomaterials in microemulsions formation mechanisms and growth control. Curr Opin Colloid Interface Sci 8 137-144 Lopez-Quintela MA, Tojo C, Blanco MC, Rio LG, Leis JR (2004) Microemulsion dynamics and reactions in microemulsions. Curr Opin Colloid Interface Sci 9 264-278 Maitra A (1984) Determination of Size Parameters of Water Aerosol Ot Oil Reverse Micelles from Their Nuclear Magnetic-Resonance Data. J Phys Chem 88 5122-5125... 

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