Table 1.
Gibbs energies of tautomers and equilibrium constants.
| Entry | Adduct (X) | Medium | ΔGketo (kcal mol−1) a |
ΔGenol (kcal mol−1) a |
Keq b |
|---|---|---|---|---|---|
| 1 | 5 (O) | Gas Chloroform |
0.0 0.0 |
4.2 3.9 |
8.0 × 10−4 1.4 × 10−3 |
| 2 | 6NH (NH) | Gas Chloroform |
0.0 0.0 |
2.0 2.5 |
3.4 × 10−2 1.5 × 10−2 |
| 3 | 6NMe (NCH3) | Gas Chloroform |
6.7 5.6 |
0.0 0.0 |
8.1 × 104 1.2 × 104 |
| 4 | 6 (NCH2C6H5) | Gas Chloroform |
7.2 6.3 |
0.0 0.0 |
1.9 × 105 4.0 × 104 |
| 5 | 6NtBu (NC(CH3)3) | Gas Chloroform |
15.1 13.4 |
0.0 0.0 |
1.2 × 1011 7.0 × 109 |
a Gibbs energy referred to the most stable tautomer. b Equilibrium constant calculated using the Arrhenius equation.