Table 1.
Compound | Solvent | λabs/nm | λema/nm | Φ fb |
---|---|---|---|---|
1 | THF | 631 | 650 | 0.61 |
2a | THF | 639 | 659 | 0.70 |
THF–H2O (4 : 1) | 643 | 667 | 0.58 | |
2b | THF–H2O (4 : l) | 650 | 676 | 0.15 |
3 | THF | 644 | 672 | 0.61 |
4 | H2O | 650 | 669 | 0.08 |
6 | CHCl3 | 661 | 704c | 0.47 |
7 | THF | 638 | 657 | 0.74 |
8 | H2O | 653 | 675 | 0.20 |
Solutions were excited at 590 nm and emission monitored in the region 600–750 nm for estimating Φf.
Fluorescence quantum yields were determined using 4,4-[bis(N,N-dimethylamino)phenyl]squaraine dye as the standard (Φf = 0.70 in CHCl3), error limit ±5%.
Solution was excited at 605 nm and emission monitored in the region 620–850 nm for estimating Φf.