Table 4.
The result of UV–Vis spectroscopy for L1-L4.
| Compound | Chromophores | Transition | λmax (nm) | ε, L mol−1 cm−1 |
|---|---|---|---|---|
| L1 | Pyridine, C O | n → π*, π → π* | 273 | 2.73 × 107 |
| L2 | Pyridine, C O | n → π*, π → π* | 273 | 2.73 × 107 |
| L3 | Pyridine, C O | n → π*, π → π* | 293 | 2.93 × 107 |
| L4 | Pyridine, C O | n → π*, π → π* | 291 | 2.91 × 107 |