Table 2.
Calculated gas-phase deprotonation energies (PA), solvation energies, and experimental and calculated pKa values
| Acid | pKa (exp)* | PA (calc, gas),† kcal/mol | ΔΔGsolvation,‡ kcal/mol | pKa, (calc)§ |
|---|---|---|---|---|
| Trifluoroacetic acid | 0.2 | 314.6 | 60.9 | −0.5 |
| Trichloroacetic acid | 0.7 | 312.7 | 59.8 | −1.0 |
| Nitrous acid | 3.3 | 331.5 | 75.8 | 0.6 |
| Dinitromethane | 3.6 | 314.9 | 53.4 | 3.8 |
| Formic acid | 3.8 | 335.6 | 74.8 | 3.4 |
| Benzoic acid | 4.2 | 333.8 | 67.9 | 6.2 |
| Acrylic acid | 4.3 | 337 | 72.2 | 5.6 |
| Hydrazoic acid | 4.6 | 336.2 | 72.6 | 4.9 |
| Acetic acid | 4.8 | 340.6 | 74.3 | 6.4 |
| Dimethyl malonate | 9 | 336.1 | 58.5 | 12.6 |
| Hydrogen cyanide | 9.2 | 346.4 | 79.6 | 6.7 |
| Phenol | 10.0 | 341.5 | 70.6 | 8.9 |
| Nitromethane | 10.2 | 352.2 | 72.1 | 14.0 |
| Methanethiol | 10.3 | 352 | 75.2 | 12.2 |
| Ethanethiol | 10.6 | 350.4 | 71.0 | 13.6 |
| Dicyanomethane | 11.2 | 328 | 55.2 | 10.0 |
| Trichloroethanol | 12.2 | 345.7 | 72.9 | 10.0 |
| Trifluoroethanol | 12.4 | 352 | 71.2 | 14.4 |
| Propargyl alcohol | 13.6 | 362.9 | 84.1 | 13.4 |
| Allyl alcohol | 15.5 | 365.8 | 84.1 | 14.9 |
| Methanol | 15.5 | 373.9 | 92.3 | 14.8 |
| Water | 15.7 | 384.7 | 102.8 | 15.0 |
| Ethanol | 15.9 | 371.0 | 88.6 | 15.2 |
| Isopropanol | 17.1 | 369.2 | 85.6 | 15.9 |
| t-Butanol | 18 | 368.5 | 83.2 | 16.8 |
| Acetone | 19.3 | 366.8 | 73.1 | 21.5 |
| Acetonitrile | 25 | 370.2 | 70.1 | 25.0 |
| Methyl acetate | 25.4 | 370.5 | 66.8 | 27.0 |
| Dimethyl sulfone | 33 | 365.7 | 56.5 | 30.0 |
| Dimethyl sulfoxide | 33.5 | 374.6 | 63.2 | 31.2 |
| HNO | 349.6 | 81.9 | 7.2 |