Table 1.
Photophysical data of COUPY fluorophores 1–6 in different solvents. a Wavelength of the absorption maximum; b Molar absorption coefficient at λmax; c Wavelength of the emission maximum upon excitation at the wavelength shown in parentheses; d Stokes’ shift (nm); e Fluorescence quantum yields, measured as described by Resch-Genger and Rurack [38] using Cresyl Violet in MeOH (ΦF = 0.55) [39] as reference.
| ||||||
|---|---|---|---|---|---|---|
| Compound | Solvent | λabs a | ε(mM−1cm−1) b | λem (λexc) c | Stokes’ Shift d | ΦF e |
| 1 | MeOH | 549 | 51.2 | 602 (546) | 53 | 0.23 |
| ACN | 548 | 41.3 | 603 (546) | 55 | 0.20 | |
| DCM | 570 | 64.2 | 603 (546) | 33 | 0.70 | |
| 2 | MeOH | 570 | 25.2 | 651 (578) | 81 | 0.02 |
| ACN | 568 | 23.9 | 654 (578) | 86 | 0.01 | |
| DCM | 601 | 37.9 | 646 (578) | 45 | 0.05 | |
| 3 | MeOH | 553 | 1.6 | 595 (546) | 42 | <0.01 |
| ACN | 554 | 2.6 | 592 (546) | 38 | <0.01 | |
| DCM | 573 | 3.8 | 604 (546) | 31 | 0.01 | |
| 4 | MeOH | 572 | 43.4 | 633 (578) | 61 | 0.14 |
| ACN | 572 | 50.4 | 638 (578) | 66 | 0.15 | |
| DCM | 598 | 65.4 | 633 (578) | 35 | 0.59 | |
| 5 | MeOH | 572 | 47.8 | 627 (578) | 55 | 0.01 |
| ACN | 572 | 39.3 | 628 (578) | 56 | <0.01 | |
| DCM | 599 | 54.0 | 637 (578) | 38 | 0.04 | |
| 6 | MeOH | 613 | 23.1 | 685 (578) | 72 | 0.03 |
| ACN | 614 | 22.9 | 690 (578) | 76 | 0.03 | |
| DCM | 652 | 35.7 | 690 (578) | 38 | 0.13 | |