UV-vis data of the dyes 1–3 in EtOH, DCM, AcCN and acidified EtOH.
| λ max EtOH | λ max DCM | λ max AcCN | λ max EtOH (H+) | |
|---|---|---|---|---|
| 1-H | 294, 334 | 302, 344 | 300, 346 | 348, 415, 492 |
| 2-OMe | 304, 344 | 318, 355 | 315, 347 | 309, 361, 440, 517 |
| 3-OCF3 | 293, 331 | 311, 337 | 306, 344 | 307, 345, 407, 481 |