Induced properties

In Chapter 16, we studied the so-called primary properties, which I defined as those that could be obtained by direct calculation from the electron density (or equivalently the wavefunction). We also touched on derivative or gradient properties. It is now time to mm our attention to those properties that measure the response of a system to an external field. In the language of Boys and Cook, these are the induced properties. 

As I mentioned earlier, this classification is not unique and other authors concentrate on classification with respect to gradients. The electric dipole can be understood as the gradient of a certain interaction energy with respect to the components of an applied field, and so on. 

Molecules do not consist of rigid arrays of point charges, and on application of an external electrostatic field the electrons and protons will rearrange themselves until the interaction energy is a minimum. In classical electrostatics, where we deal with macroscopic samples, the phenomenon is referred to as the induced polarization. I dealt with this in Chapter 15, when we discussed the Onsager model of solvation. The nuclei and the electrons will tend to move in opposite directions when a field is applied, and so the electric dipole moment will change. Again, in classical electrostatics we study the induced dipole moment per unit volume. 

Both the permanent dipole and the applied field are vector quantities, and the direction of the induced dipole need not be the same as the direction of the applied field. Hence, we need a more general property than a vector to describe the polarizability. 

Since we normally deal with electrostatic field perturbations that are small, we can profitably expand the electric moments as a Taylor series in the external field  

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Studies have considered the effect of crystallinity on the performance of CR adhesives (97), on segmental mobiUty as determined by nqr studies (101), on strain induced property changes (102), and on relaxation processes (103). 

Thirdly, induced properties are those that measure the response of a system to an applied field. I will concentrate on polarizabilities (for which the external field is electric) and magnetizabilities (for which the apphed field is magnetic) in a later chapter. 

The adverse properties of red beet preparations are without doubt, their high nitrate content, their unpleasant smell due to pyrazine derivatives and geosmin with a low odor threshold, and finally the risk of carry-over of earth-bound germs. - " Since nitrate has been associated with nitrite and nitrosamine formation, the latter exhibiting cancer-inducing properties, procedures have been developed to reduce the nitrate content of red beet preparations. This has been achieved by microbial denitrification. - ... 

The atomic properties satisfy the necessary physical requirement of paralleling the transferability of their charge distributions - atoms that look the same in two molecules contribute identical amounts to all properties in both molecules, including field-induced properties. Thus the atoms of theory recover the experimentally measurable contributions to the volume, heats of formation, electric polarizability, and magnetic susceptibility in those cases where the group contributions are found to be transferable, as well as additive additive [4], The additivity of the atomic properties coupled with the observation that their transferability parallels the transferability of the atom s physical form are unique to QTAIM and are essential for a theory of atoms in molecules that purports to explain the observations of experimental chemistry. 

To improve the interfacial bonding between the PP fiber and a cementitious matrix, commercially available PP fibers with different geometries were fluori-nated and the effect evaluated with regard to crack control, impact resistance (AC1 Committee 544 Report), and water absorption (ASTM C-948).M,34a In all cases, as seen in Table 16.13, fluorination improved the induced properties. 

Unfortunately, direct Ugi reaction of 85 predominantly led to the formation of DHOPs (87) [172]. However, by applying a MCR-alkylation-MCR strategy, the Ugi products (88) could be isolated in high yields [173]. The obtained conformationally constrained peptidomimetics allow for unprecedented diversification and were ultimately evaluated for their turn-inducing properties, indicating an open turn structure for 88a (Fig. 27). 

CYP450 Rifabutin has liver enzyme-inducing properties. The related drug, rifampin, is known to reduce the activity of a number of other drugs. Because of the structural... 

Has liver enzyme-inducing properties similar to rifampin although less potent... 

Prolonged use of medications with sleep-inducing properties, such as sedatives or antihypertensives... 

Ternary and Other Induced Spectra. Three-particle induced dipoles and the associated ternary collision-induced absorption spectra and dipole autocorrelation functions have been studied for fluids composed of mixtures of rare gases, and for neat fluids of nonpolar molecules — that is for systems that are widely thought to interact with radiation only by virtue of interaction-induced properties. A convenient framework is thus obtained for understanding the variety of experimental observations. The computer simulation studies permit an insight into the involved basic processes, but were not intended for direct comparison with measurements [57]. Methods have been developed for computer... 

Symmetry-adapted perturbation theory applied to interaction-induced properties of collisional complexes. Molec. Phys., 89 81, 1996. 

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