Handbook of Solvents - George Wypych - ChemTech - Ventech!

716 Ranieri Urbani and Attilio Cesàro
Figure 12.2.6. Conformational energy maps calculated for (a) D-maltose and (b) D-cellobiose. Contours are in
kcal·mol -1 with increments above the minimum (x) of 0.5 kcal·mol -1 .
Figure 12.2.7. General scheme of the theoretical approach
for the solvation energy calculation.
where the total conformational free energy,
G tot, is given by the sum of the contribution
due to the in vacuo conformational state energy,
G conf, and the solvation contribution,
G solv. The latter term is a sum of contributions
due to the energy required to create, in
a given solvent, a cavity of suitable size to
accommodate the solute molecule in a
given conformational state and the interaction
energy between the solute and the surrounding
solvent molecules, as
schematically shown in Figure 12.2.7: 49
Gsolv = Gcav + Gel + Gdisp
[12.2.2]
The expression for G cav, that is the free
energy required for the formation of a cavity
(first step in Figure 12.2.7), at a temperature
T and a pressure P, is taken from the
Scaled Particle Theory (SPT) which has
been successfully applied in the study of
thermodynamic properties of aqueous and
non-aqueous solutions: 47,50