| Tautomers | ΔfH (Kcal.mol−1) | ΔrH (Kcal.mol−1) | equilibrium | Keq1 | Keq2 |
| Gas phase | |||||
| Q-4-one | −299399.8 | 6.957 | Q-4-one ↔ Q-4-hydroxy | 0.982 | 1.018 |
| Q-4-hydroxy | −299392.9 | ||||
| DMQ | −443115.7 | 0.464 | DMQ ↔ DMHQ | 0.997 | 1.003 |
| DMHQ | −443115.7 | ||||
| DBrQ | −3529303.0 | 3.773 | DBrQ ↔ DBrHQ | 0.989 | 1.011 |
| DBrHQ | −3529299.2 | ||||
| DMF | |||||
| Q-4-one | −299409.9 | 14.680 | Q-4-one ↔ Q-4-hydroxy | 0.997 | 1.003 |
| Q-4-hydroxy | −299394.8 | ||||
| DMQ | −443121.4 | 3.591 | DMQ ↔ DMHQ | 0.989 | 1.011 |
| DMHQ | −443117.6 | ||||
| DBrQ | −3529306.8 | 7.323 | DBrQ ↔ DBrHQ | 0.98 | 1.021 |
| DBrHQ | −3529299.2 | ||||