Alcohol increasing basic strength

The formation of a weakly basic tertiary amine in reaction 4.102 does not alter the titrant normality, but in the titration of an acid it may suppress the height of the titration curve on the basic side. In an extensive study of twelve quaternary ammonium titrants in non-aqueous media (mainly isopropyl alcohol), Harlow73 observed large differences in stability the presence of water had a profound stabilizing action but at the sacrifice of basic strength inert and basic solvents increased the rate of decomposition (see Fig. 4.18). 

The ease of alkoxo group exchange also depends on the respective M—O and O—H bond strengths and steric factors. Alkoxo group exchange proceeds by nucleophilic attack of R OH to the Lewis acidic metal center. Therefore, any electronic effect that increases the Lewis acidity of the metal or the Lewis basicity of the entering alcohol (relative to the leaving alcohol) facilitates the reaction. 

The increase in temperature enhances the dissociation of water and leads to a decrease in its acidity scale (defined by — log Ke). The strength of acids and bases is therefore appreciably modified compared with normal conditions. Concurrent with the decrease in the dielectric constant of the medium, the effect of hydrothermal conditions on the behavior of acid-base couples of the type HA/A and may therefore be very different. This is the case for solvents such as water or alcohol, for example [43). This explains why (he basicity of the chlorine ion is much higher under hydrothermal conditions. In water at 500°C and 2kbar, the equilibrium constant of... 

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