Water diamagnetic susceptibility

For the spherical compartment (IMCL), the BMS is determined by the diamagnetic susceptibility outside the sphere (muscular water), and can therefore be approximated by... 

The diamagnetic susceptibility is a measure of the averaged electronic distribution in bulk matter. Careri et al. (1977, 1980) showed that the differential diamagnetic susceptibility per gram of water adsorbed on lysozyme powders reached the bulk water value at 0.2 h. Lysozyme behaved as a normal diamagnetic substance. The diamagnetic susceptibility and the enthalpy of sorption for lysozyme change similarly at low hydration. 

The effect of "residual water" on either protein stability or enzyme activity continues to be a topic of great interest. For example, several properties of lysozyme (e.g., heat capacity, diamagnetic susceptibility (Hageman, 1988), and dielectric behavior (Bone and Pethig, 1985 Bone, 1996)) show an inflection point at the hydration limit. Detailed studies on the direct current protonic conductivity of lysozyme powders at various levels of hydration have suggested that the onset of hydration-induced protonic conduction (and quite possibly for the onset of enzymatic activity) occurs at the hydration limit. It was hypothesized that this threshold corresponds to the formation of a percolation network of absorbed water molecules on the surface of the protein (Careri et al., 1988). More recently. Smith et al., (2002) have shown that, beyond the hydration limit, the heat of interaction of water with the amorphous solid approaches the heat of condensation of water, as we have shown to be the case for amorphous sugars. 

Carerl, G.C. Gratton, E. Yang, P.-H. Rupley, J.A. "Protein-Water Interactions. Correlation of Infrared Spectroscopic, Heat Capacity, Diamagnetic Susceptibility and Enzymatic Measurements on Lysozyme Powders," submitted for publication, 1979. 

Weak diamagnetic materials have magnetic susceptibility values close to zero their molar magnetic susceptibility is of the order of Xmoi = —10 x Kr9m3mol 1. Diamagnetic susceptibility is a temperature independent quantity (Fig. 7.1). Some diamagnetic materials (water, benzene) are used to calibrate (check) the experimental equipment. 

Liquid water attacks the 123 compound more severely than water vapor. Samples of this material were found to lose one-third of their diamagnetic susceptibility upon exposure to distilled water at 60°C for 5 min [59]. The mechanism of attack followed the same reaction sequence indicated for water vapor, given by Equations 5.21a through 5.21c [60]. 

A diamagnetic body such as a droplet of water has, by its very definition, negative magnetic susceptibility. In the presence of a magnetic field, a force acts on the body when the scale of the magnetic-field... 

Hydrogen peroxide is diamagnetic, and that to a greater extent than water. Representing magnetic susceptibility by K, the values for air, water and peroxide at 10 C. are as follow 5... 

Neglecting the third term of Eq. (12), the mass susceptibility of a paramagnetic solute is readily determined from m and Ai. The diamagnetic mass susceptibilities 0 of the solvents, in SI units of m kg are -8.8 X 10 (benzene), —9.0 X 10 (toluene), and -9.0 X 10 (t-butyl alcohol-water solvent). For temperature-dependence studies, correct m according to Eq. (18), calculate A A/and plot versus HT. The slope of the best straight... 

Phenoxaselenin is oxidized in acetonitrile at a platinum anode to give a cation-radical. However, this radical gave a broad, featureless ESR spectrum from which only a Se hyperfine splitting of 39.5 G could be measured. The radical dimerizes to a diamagnetic product, a process which has been studied in acetonitrile and in concentrated sulfuric acid, The radical is also susceptible to nucleophilic attack at Se by water in these solvents. Galasso s study of -factors in group VI heterocyclic radicals included phenoxaselenin cation-radical. ... 

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