Table 5.
Axial Ligand Substitution Rate Constants of [Co(Schiff base)(L)2]+ Complexes at 37 °C and Activation Parameters Determined by Eyring Analysis
| Complex | k1 × 107 (s−1) (37 °C) | k2 × 107 (s−1) (37 °C) | k1 ∆H‡ (kJ/mol)a | k1 ∆S‡ (J·mol−1 ·K−1) a | k2 ∆H‡ (kJ/mol) a | k2 ∆S‡ (J·mol−1 ·K−1)) a |
|---|---|---|---|---|---|---|
| [Co(3F-salen)(NH3)2]+ | 64.5 ± 0.6 | 33.5 ± 0.2 | 115.3 ± 1.8 | 27.6 ± 0.9 | 130.1 ± 2.9 | 69.9 ± 2.3 |
| [Co(3F-salen)(3F-BnNH2)2]+ | 734 ± 40 | 164 ± 9 | 115.7 ± 3.7 | 50.2 ± 2.4 | 119.3 ± 1.8 | 49.3 ± 1.8 |
| [Co(tfacen)(NH3)2]+ | 39.6 ± 0.2 | 7.98 ± 0.7 | 115.6 ± 0.7 | 24.0 ± 0.2 | 137.4 ± 3.4 | 78.9 ± 2.9 |
| [Co(tfacen)(3F-BnNH2)2]+ | 172 ± 1.0 | 22.5 ± 0.7 | 115.0 ± 3.0 | 35.8 ± 1.3 | 129.4 ± 4.6 | 66.0 ± 3.7 |
a
Values obtained from Eyring-style plots of reaction rate constant versus temperature. The reported errors are the standard errors based on the least square regression analysis of the data.