Table 4. Ion size parameters and values of − log BH for benzoic acids.
| Substituent | Ion size parameter | − Log BH | ||
|---|---|---|---|---|
| Å | ||||
| Hydrogen | 1.25 | 0.10a | 3.46 | 0.17b |
| m-Allyl | 1.19 | 0.07 | 3.40 | 0.18 |
| p-Allyl | 1.25 | 0.07 | 3.57 | 0.17 |
| m-Propenyl | 1.22 | 0.06 | 3.43 | 0.15 |
| p-Propenyl | 1.44 | 0.10 | 4.10 | 0.18 |
a
Estimated standard deviation calculated from the estimated variance of the slope of the pK + log [H2O] against 1/ϵ plot using the method given in reference 22.
b
Estimated standard deviation calculated from the estimated variance of the intercept using the method given in reference 22.