Table 2.
Redox potentials, redox stability and conversion after 5 h in anis alcohol oxidation of mediators (10 mM), measured in 0.1 M NaOAc‐buffer, pH 4.5, at a scan rate of 100 mV s−1. Entries 1–7: Stable N‐Oxyl radicals (ionic mechanism); Entry 8: ABTS (ET‐mechanism); Entry 9–11: N‐hydroxy type mediators (HAT‐mechanism).
|
Entry |
Mediator |
E1/2 [mV] vs. NHE |
Conversion to 2 after 5 h [%] |
Redox stability |
|---|---|---|---|---|
|
1 |
Hydroxy‐TEMPO (5) |
693 |
84±4 |
+ |
|
2 |
TEMPO (4) |
696 |
61±5 |
+ |
|
3 |
Methoxy‐TEMPO (8) |
702 |
85±5 |
+ |
|
4 |
Acetamido‐TEMPO (7) |
704 |
78±4 |
∼ |
|
5 |
AZADOL (3) |
774 |
94±3 |
+ |
|
6 |
Amino‐TEMPO (14) |
806 |
11±0 |
+ |
|
7 |
Oxo‐TEMPO (9) |
806 |
7±1 |
− |
|
8 |
ABTS (11) |
742 & 802 |
31±8 |
+ |
|
9 |
VLA (13) |
987 |
45±3 |
+ |
|
10 |
NHP (10) |
1168 |
27±3 |
+ |
|
11 |
HBT (12) |
Not determinable[a] |
51±3 |
[a] |
[a] No distinct redox transition observed within the solvent window.