| Molecule | pKa(1) | pKa(2) | pKa(3) | DH, kcal/mol, Gas (4) |
|---|---|---|---|---|
| PhCH3 | 41.2 | 43 | 39 | 381 |
| Ph2CH2 | 33.4 | 32.3 | 31 | -- |
| Ph3CH | 31.4 | -- | 30.6 | -- |
| Fluorene | 22.7 | 22.6 | -- | 351.8 |
| Indene | 19.9 | 20.1 | -- | -- |
| Cyclopentadiene | 16.6 | 18.1 | -- | -- |
| Methane | -- | -- | 48 | 418.8 |
| Ethane | -- | -- | 51 | 419.0 |
| Ethylene | -- | -- | -- | 407.5 |
| Cyclopropane | -- | -- | -- | 411.5 |
| Cyclopentane | -- | -- | 49 | -- |
| Benzene | -- | -- | -- | 400.8 |
| Cyclohexene | 45 | -- | -- | 386.5 |
| Phenylacetylene | 23.2 | -- | -- | 370.7 |
| Ammonia | -- | -- | -- | 403.6 |
| Acetone | -- | 20 | -- | -48.5 |
| tBuOH | -- | -- | -- | -65.8 |
1. Based on H exchange with cesium cyclohexylamide in cyclohexylamine
2. Based on H exchange with dimsyl potassium in DMSO
3. From electrochemical reduction of radicals in DMF
4. ICR measurements of BH = B- H+