Table 5.
Photophysical properties of 1H-pyridines 5.
| Entry | Compound | R1 | R2 | λmax,abs [nm]a (ε [L·mol−1·cm−1]) | λmax,em [nm]b (Φf)c | Stokes shift Δν̃ [cm−1] |
| 1 | 5a | Ph | Ph | 281 (26100), 319 (17400), 418 (9800) | 545 (0.02) | 5600 |
| 2 | 5b | p-F3CC6H4 | Ph | 272 (27000), 326 (17500), 424 (8900) | 565 (0.01) | 5600 |
| 3 | 5c | p-NCC6H4 | Ph | 280 (37600), 333 (17300), 431 (9500) | 585 (0.01) | 6100 |
| 4 | 5d | Ph | p-F3CC6H4 | 274 (32000), 321 (18100), 428 (10000) | 565 (0.01) | 5700 |
| 5 | 5e | Ph | p-NCC6H4 | 283 (36000), 322 (15600), 434 (8600) | 579 (0.01) | 5800 |
| 6 | 5f | p-MeOC6H4 | p-F3CC6H4 | 261 (26200), 306 (28400), 429 (10400) | 557 (0.02) | 5400 |
| 7 | 5g | p-F3CC6H4 | p-MeOC6H4 | 260 (20300), 324 (43800), 420 (10000) | 562 (0.02) | 6000 |
| 8 | 5h | 2-thienyl | Ph | 273 (21800), 308 (26700), 433 (9200) | 560 (0.03) | 5200 |
aRecorded in dichloromethane, T = 293 K, c(5) = 10−6 M; brecorded in dichloromethane, T = 293 K, c(5) = 10−7 M; cfluorescence quantum yields were determined relative to coumarin153 (Φf = 0.54) as a standard in ethanol [58].