| Tautomers | HOMO (eV) | LUMO (eV) | ΔE(eV) |
| Gas phase | |||
| Q-4-one | −6.248 | −1.355 | 4.893 |
| Q-4-hydroxy | −6.295 | −1.516 | 4.779 |
| DMQ | −5.429 | −0.827 | 4.603 |
| DMHQ | −5.462 | −0.964 | 4.498 |
| DBrQ | −6.303 | −1.844 | 4.459 |
| DBrHQ | −6.435 | −2.049 | 4.387 |
| DMF | |||
| Q-4-one | −6.157 | −1.488 | 4.669 |
| Q-4-hydroxy | −6.050 | −1.595 | 4.455 |
| DMQ | −5.599 | −1.145 | 4.453 |
| DMHQ | −5.628 | −1.238 | 4.389 |
| DBrQ | −6.305 | −1.879 | 4.427 |
| DBrHQ | −6.458 | −2.041 | 4.417 |