Logarithms of the equilibrium constants for the interaction of Zn2+ with L124 and L2 obtained by potentiometric measurements. The logarithms constants were determined in 0.15 M NaClO4 at 298.1 ± 0.1 Ka.
| Entry | Reaction | L124 | L2 |
|---|---|---|---|
| 1 | [CuZnH2(H−1L)]5+ + H+ ⇄ [CuZnH3(H−1L)]6+ | — | 5.58(4) |
| 2 | [CuZnH(H−1L)]4+ + H+ ⇄ [CuZnH2(H−1L)]5+ | — | 7.11(4) |
| 3 | Cu2+ + Zn2+ + H−1L− + H+ ⇄ [CuZnH(H−1L)]4+ | — | 33.54(5) |
| 4 | Cu2+ + Zn2+ + H−1L− + H2O ⇄ [CuZn(H−1L)(OH)]2+ + H+ | 19.93(5) | 17.42(5) |
| 5 | Cu2+ + Zn2+ + H−1L− + 2H2O ⇄ [CuZn(H−1L)(OH)2]+ + 2H+ | 12.19(3) | 9.10(5) |
| 6 | Cu2+ + Zn2+ + H−1L− + 3H2O ⇄ [CuZn(H−1L)(OH)3] + 3H+ | 1.20(7) | — |
a
Values in parentheses are standard deviations in the last significant figure.