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Natural charging electrostatic effects

The model adopted by Ri and Eyring is not now acceptable, but some of the more recent treatments of electrostatic effects are quite close to their method in principle. In dealing with polar substituents some authors have concentrated on the interaction of the substituent with the electrophile whilst others have considered the interaction of the substituent with the charge on the ring in the transition state. An example of the latter method was mentioned above ( 7.2.1), and both will be encountered later ( 9.1.2). They are really attempts to explain the nature of the inductive effect, and an important question which they raise is that of the relative importance of localisation and electrostatic phenomena in determining orientation and state of activation in electrophilic substitutions. [Pg.136]

The electrostatic force is directly proportional to the net charge of an aerosol particle. Therefore, effective charging of the particles is of great importance. Airborne particles are normally charged either due to their birth processes or due to charge transfer from gas ions to particles. The natural charging of particles is normally so weak that it has no practical importance for electrostatic air cleaning. [Pg.1213]

Balance between repulsive and attractive electrostatic effects depends on charges q +, q- (electronegativity differences of the C-X bonds) or the nature of the dipole (type of bonds) and their orientation. In the case of acetals, one needs to consider an ensemble of not only two dipoles but of, at least, four (Fig. 4). [Pg.14]

In summary, it is dear that the zeolite is a novel host for the entrapment of molecules and the rigidity and the charged nature of the framework allow for steric and electrostatic effects on the encapsulated molecules. Isolation of entrapped molecules can also influence their reactivity. The interest in zeolites as hosts for electron-transfer reactions stems from a combination of properties, including... [Pg.2795]

It is useful to compare the PQS values calculated by Bancroft and from a modern version (Table 18). The modified PQS scale can be obtained from the Bancroft scale by adding 1.3 mm s b This difference was obtained by comparing the PQS values for nioxime, phenanthroline, and bipyridine complexes in both scales. All PQS values obtained are positive, in contrast to Bancroft s scale with negative PQS for all ligands except NO. It is clear that the nature of PQS is rather different from the pure electrostatic effect of the charge of ligand atoms. The reason for a positive PQS value is a decrease in... [Pg.200]

Sternberg, M., F. Hayes, A. Russell, P. Thomas and A. Fersht. (1987). Prediction of electrostatic effects of engineering of protein charges. Nature. 330 86. [Pg.234]


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See also in sourсe #XX -- [ Pg.1535 ]




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Charge effective

Charge, effect

Charging effect

Electrostatic charge effects

Electrostatic charges

Electrostatic effectiveness

Electrostatic effects

Natural charges

Natural effect

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