Table 1.
Characterization of precursors tested using the agar-plate screening test
| Name of precursor | Acronym | Substituents | Eo (mV) | Er (mV) |
|---|---|---|---|---|
| benzene derivatives | ||||
| 1,2-dihydroxybenzene | Cat | 1-OH, 2-OH | 548 | 285 |
| aniline-2-sulfonic acid | A2SA | 1-SO3H, 2-NH2 | 1013 | -0.5 |
| 3-aminobenzenesulfonic acid | 3ABS | 1-SO3H, 3-NH2 | 968 | 5.4a |
| 3-amino-4-hydroxybenzenesulfonic acid | AHBS | 1-SO3H, 3-NH2, 4-OH | 518 | -103 |
| 2,4-diaminobenzenesulfonic acid | 2,4DABS | 1-SO3H, 2-NH2, 4-NH2 | 818 | |
| 2,5-diaminobenzenesulfonic acid | 2,5DABS | 1-SO3H, 2-NH2, 5-NH2 | 433 | -356a |
| 3-amino-4-hydroxy-5-nitrobenzenesulfonic acid | AHNBS | 1-SO3H, 3-NH2, 4-OH, 5-NO2 | 339a, 579 | -92 |
| 5-sulfosalicylic acid hydrate | 5SSA | 1-COOH, 2-OH, 5-SO3H | - | - |
| 2-formylbenzenesulfonic acid sodium salt | 2FBSA | 1-SO3Na, 2-CHO | - | - |
| 4,5-dihydroxy-1,3-benzene-disulfonic acid | dHBdSA | 1-SO3Na, 3-SO3Na, 4-OH, 5-OH | 914b | |
| 2-amino-3-hydroxypyridine | 2A3HP | 2-NH2, 3-OH | 647 | 144, 6.8 |
| 2-phenylphenol sodium salt tetrahydrate | 2PP | 2-ONa | 790 | |
| naphtalene derivatives | ||||
| 2,7-dihydroxynaphtalene | DHN | 2-OH, 7-OH | 672 | |
| 6-hydroxy-2-naphthalenesulfonic acid sodium salt | HNSA | 2-SO3Na, 6-OH | 893 | -144 |
| 4-amino-3-hydroxy-1-naphthalenesulfonic acid | 4AHNS | 1-SO3Na, 3-OH, 4-NH2 | 251 | 194,-1.4 |
| 6-amino-4-hydroxy-2-naphthalenesulfonic acid | 6AHNS | 2-SO3Na, 4-OH, 6-NH2 | 499 | |
| 5-amino-1-naphthalenesulfonic acid | ANS | 1-SO3Na, 5-NH2 | 680 |
Table summarizes the chemical structure of precursors in comparison with their oxidation (Eo) and reduction (Er) potentials. The potentials of the precursors were obtained at the scan rate 50 mV/s with the exception of dHBdSA, which was tested at the scan rate 25 mV/s. a very small peak, b scan rate - 25 mV/s.