Strong-binding approximation

In the strong-binding approximation, valid for an aromatic molecular crystal, the intramolecular degrees of freedom are practically uncoupled in... 

The picture described corresponds to the so-called strong-binding approximation. In a weak-binding approximation the electron behavior in a periodic crystal field is considered. For the analysis of the latter case it is necessary to solve the Schrbdinger equation for a particle moving in a periodic field F. Bloch has offered a function consisting of the product of two functions ... 

In response to the presence of detrimental Cd +, Hg +, Pb +, and other heavy metal ions, the human hver and kidneys synthesize more metallothionein, an unusual small protein in which approximately one-third of the 61 amino acid residues are cysteine see Metallothioneins). The frequency and juxtaposition of sulfhydryl groups provide strong binding sites for several heavy metal ions. Though not as profusely as metallothionein, many proteins contain sulfhydryl groups that may become metalated by toxic heavy metal ions such as Cd +, Hg +, and Pb +, and it is widely believed that this complex formation explains the toxicity of these metal ions. The exact proteins where the most consequential damage occurs remain uncertain. 

Finally, we attempt to propose a hydration model of the mucopolysaccharides, at least In the deeply cooled solutions. The model is shown In Figure 13. The data in Table HI clearly indicate that, similar to non-lonlzable hydrophilic polymers (8), the mucopolysaccharides chains are associated with a rather small number of water molecules, so that It may not be adequate to use the word "shell to show their sequence of association. Not only the Ionic but also hydroxyl groups strongly bind a few (approximately two) molecules of water (Wnf) per hydrophilic group and are further... 

The FQ complexation parameters were much less sensitive to pH than the ISE parameters. For Well 1, ISE showed no significant binding at pH 6 but strong binding at pH 8.3. The FQ titration curves for Well 1, on the other hand, showed approximately the same amount of quenching at pH 6 as at pH 8.3. This implies that FQ may not be a reliable independent metal speciation method. Cabaniss and Shuman (41) have suggested that FQ may be a useful speciation method if fluorescence is calibrated by another method, such as ISE. The results of the present work suggest that FQ may not be useful without calibration. 

When the energy levels of the occupied orbitals in the spherical potentials are added up, one obtains the electronic energy of the cluster of size n, E n) = T,nE n). When this energy is plotted as a function of n, it shows particularly strong binding when a shell is completed. However, on the average it has a monotonic behavior that is often approximated as... 

Association constants were determined by Cram extraction methods, which revealed that the macrocycle 50 formed a strong complex with chloride (12 800 1300 M ). Proton NMR titration experiments conducted in CD2CI2 also revealed the size dependence selectivity of the caUx[n]pyrroles where bromide was foimd to bind approximately seven times stronger to the larger caUx[6]pyrrole compared to calix[4]pyrrole (710 25M for 50 against 10 for 47) [68]. 

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