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Properties of Parent and F-labeled pH indicators
| Parent Compound |
Mono- fluorinated |
Di- fluorinated |
||||
|---|---|---|---|---|---|---|
| Indicator name | pKa | λ max | pKa | λ max | pKa | λ max |
| Phenol Red | 7.9 | 558 | 7.3 | 564 | 6.4 | 570 |
| Cresol Red | 8.2 | 572 | 7.6 | 576 | 6.8 | 582 |
| Cresol Purple | 8.3 | 578 | 7.5 | 582 | 7.0 | 590 |
| Phenolphthalein | 9.7 | 553 | 9.3 | 558 | 8.7 | 564 |
| Naptholphthalein | 7.8 | 653 | 7.7 | 659 | 7.2 | 665 |
λmax is the absorbance maximum of the basic form in nm.
