Some Correlations of Rates with Solubility Parameter

10 SOME CORRELATIONS OF RATES WITH SOLUBILITY PARAMETER 

A reaction that is widely cited as one in which solvent polarity plays a major role is the formation of quaternary ammonium salts as shown in the 

For this reaction, it was found that the rate increases when solvents having large solubility parameters are used. Moreover, the volume of activation for the reaction is negative in aU of the solvents, but it is more negative in solvents having smaller solubility parameters. 

The free energy of activation for a reaction having a compact, polar (or ionic) transition state wiU be decreased by solvents having large solubility 

FIGURE 5.6 Relationship between the rate constants for the reaction shown in Eq. (5.126) and the solubility parameter of the solvent. (Constructed using the data of Kondo, et al. (1972).) 

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