Table 4.
The observed decay rate constants (kd) of triplet species formed from 4, 3b and 3c in H2O/CH3CN (98:2, v/v) upon excitation at λexc = 266 nm
| compound (observed transient) |
λobs / nm |
kd (aerated) / 106 s−1 |
kd (degassed) / s−1 |
|---|---|---|---|
| 4 (3q4*) | 380 | (1.0 ± 0.3) | (4.3 ± 0.2) × 104 |
| 425 | (1.2 ± 0.3) | (5.3 ± 0.2) × 104 | |
| 500 | (1.6 ± 0.2) | (3.9 ± 0.3) × 104 | |
| 3b (3q3b*) | 380 | (1.0 ± 0.1) | (2.4 ± 0.2) × 105 |
| 425 | (1.3 ± 0.2) | (2.6 ± 0.2) × 105 | |
| 500 | (1.3 ± 0.4) | (3.3 ± 0.2) × 105 | |
| 3c (33c−*) | 460 | (1.7 ± 0.2) | (5.0 ± 0.4) × 105 |