Calorimetry electrostatic interactions

F a aiid are considered to be the susceptibiUties of the acid and base to undergo electrostatic interactions, and Ca and Cg are their susceptibilities to form covalent bonds. The heats of reaction can be measured by direct calorimetry or from shifts in IR spectra. An example of the latter is the shift in the OH stretching frequency of phenols (Av), when they react with amines in tetrachloromethane or tetrachloroethene, which is given by Eq. (4) [2]. 

When the adsorption of organic molecules is governed by non-electrostatic interactions, such as TT-TT-dispersion or hydrophobic interactions, the area of the adsorbent occupied by the adsorbate depends on the porosity of the former and the molecular size of the latter. Thus, it has been shown by Stoeckli etal. (2001), using immersion calorimetry measurements, that... 

Barton et al. (1972) used immersion calorimetry with butyl derivatives with different polarity (n-butanol, -butyric acid, -butyl chloride, n-butylaldehyde, n-butyl nitrile and n-butylamine) to study the polarity of the surface of graphite covered by surface oxygen complexes. For a non-polar liquid such as n-hexane, the enthalpies of immersion of the oxidized graphite and that of an oxygen-free sample were similar, this indicating that the surface polarity hardly affects the interaction with -hexane. However, a series of different values were obtained with the butyl derivatives, which were attributed to the interaction of the electrostatic field at the surface with the dipole moment of the molecules of these wetting liquids. 

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