The ionization constants (k1 and k2), of 2HPy and 2MPy, their X- and N-methyl derivatives (k1(XMe) and k1(NMe)) and the equilibrium constants (KT = [B]/[A]) in the water at room temperature.
| k 1, k2, KT, ΔG | 2-Hydroxypyridine | 2-Mercaptopyridine |
|---|---|---|
| pk1 | 0.76 ± 0.01 (0.75) | −1.38a (—) |
| pk2 | 12.14 ± 0.02 (11.62) | 10.10 ± 0.01 (9.81) |
| pk1(XMe) | 3.25 ± 0.01 (3.28) | 3.37 ± 0.01 (3.59) |
| pk1(NMe) | 0.31 ± 0.01 (0.32) | — |
| K T | 912 ± 29 (910) | 56 230 ± 1000 (70 000) |
| log KT | 2.96 ± 0.01 (2.96) | 4.75 ± 0.01 (4.82) |
| ΔG (kJ mol−1) | −16.88 ± 0.06 (−16.90) | −27.09 ± 0.06 (−27.50) |
a
From ref. 17. The literature values are listed in the parenthesis.